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HP 8970B User's Manual

1. Enter IF and LO Frequencies IF for Modes 1 1 amp 1 3 for Modes 1 6 amp 1 8 zZ mel lt NC 30 MHz30 MHz Fixed IF or LO Frequency Selection LO for Modes 1 2 amp 1 4 for Modes 1 7 amp 1 9 Display the User Con trolled LO Frequency in Measurement Modes 1 6 through 1 9 3 0 IF 3 1 LF 3 2 UL none Normal Talker and NY NC NC On Controller Cap ae Listener Leen ae z ae os ability of the Noise Figure none Talk Only NIY Meter ENR THOT Use ENR Table NY Spot ENR Tror Settings and Use Spot ENR YY Tcoup and ENR a R Table Display Current ENR NIN Table Selection election in dB Enter and Use Spt ENR N Y Enter and Use THOT NIY Enter Noise Source NIY Identifier Noise Source catalog NIN ENR table number for Nii Y calibration ENR table number for NIY the measurement TCOLD TC Enter TCOLD Spot ENR Tron Setting Tootp and ENR Table Selection z we z zzzzz A AZ Bee Zed 2 Output to Noise Figure and Gain N Y Data Output to Oscilloscope Test Pattern NIY Oscilloscopes Noise Figure Only NiY ia re and Gain Only N Y Cursor enabled for oscil N Y loscope display Cursor disabled for oscil N Y loscope display Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes
2. b Select the start stop and step size frequencies using the START FREQ STOP FREQ and STEP SIZE keys Refer to the Sweep Detailed Operating Instruction for an explanation of START FREQ STOP FREQ and STEP SIZE c The Noise Figure Measurement System is now ready to perform a Fine Tuning Calibration The Fine Tuning Calibration will be performed each time the Noise Figure Measurement System is calibrated if Special Function 36 0 has been selected Or Special Function 36 3 can be selected to perform a Fine Tuning Calibration from the START FREQ to the STOP FREQ immediately The calibration will take from five to ten seconds per frequency point NOTE When a Fine Tuning Calibration has been enabled and the decimal point is flashing in the NOISE FIGURE display the Noise Figure Test Set is not at operating temperature The calibration cannot be com pleted until the instrument is up to temperature The Noise Figure Meter is waiting for the YIG filter temperature control loop in the Noise Figure Test Set to lock The flashing decimal can also be caused by a power loss to the Noise Figure Test Set The time needed for the temper ature control loop to lock could be fifteen minutes if the Noise Figure Test Set was cold or four to five minutes if the Noise Figure Test Set was warmed up before it lost power When the loop locks the Fine Tuning Calibration will be completed Itis normal for the system local oscillator to change frequency a
3. HP 8970B Uperation Fixed IF or LO Frequency Selection cond Special Functions 3 and 19 Procedure To select a fixed IF or LO frequency key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Next enter the appropriate value using the DATA keys and press ENTER 5 ael En z 5E Z 28 Z Special Function Program Se agi E SS 22 toc 8 E3 S g5 5 2 code CEE 2 3s 2a El amp 3 Fixed IF 3 0 IF or N Y Y NC 30 30 for modes 1 1 and 1 3 3 0SP MHz MHz for modes 1 6 and 1 8 3500 MHz Fixed LO Frequency 3 1 LF or N Y Y NC 10000 10000 for modes 1 2 and 1 4 3 1SP MHz MHz for modes 1 7 and 1 9 44000 MHz Display User Controlled 3 2 ULor N N N OFF OFF OFF LO frequency in 3 25P Measurement Modes 1 5 through 1 9 Fixed IF for Noise 19 2 S2 or N Y Y NC 700 700 Figure Test Set 19 2SP MHz MHz band 2 SSB2 Fixed IF for Noise 19 3 S3 or N Y Y NC 450 450 Figure Test Set 19 35P MHz MHz band 3 SSB3 Fixed IF for Noise 19 4 S4 or N Y Y NC 25 25 Figure Test Set 19 4SP MHz MHz band 4 DSB Display Noise Figure 19 5 S5 or N N N NC NC NC Meter input frequency 19 5SP Example To select a fixed IF of 70 MHz LOCAL pom CODE mmm Function poms Data mom Function men OOO la OF P HP B 4 IF70MZ Function E I T iy eea Function program codes Data 3 111 Operation Program Codes lt gt indications Comments Related Sections 3 112 HP syv 0B
4. ee Fixed Exponent ENR Table Number ENR Table Entry Number ENR Catalog 80 TNNE 06 Fixed Data L_ Fixed Exponent ENR Table Number ENR Table Entry Number or Entries in Table Noise Figure Test Set Fine Tuning Calibration 80363E 06 Fixed Data Fixed Exponent Special Function number fora Fine Tuning Calibration Noise Figure Test Set Coarse Tuning Calibration 80640E 06 Fixed Data as Li Fixes Exponent Specia Function number for a Coarse Tuning Calibration One purpose for these special codes would be to read back from the Noise Figure Meter until the codes stop being sent which would mean the task is complete This would be useful when doing a coarse of fine tune calibration Timeouts should not be used with these special codes Ifa timeout is used it should be at least sixty seconds This is necessary because it may take the Noise Figure Meter many seconds to set up the special code for output This is the case for coarse and fine tune calibration There are three types of error displays All three use the format shown above to output the error message to the HP IB The following examples illustrate each type The display above shows the general error display format E means error while the number is the error code HP 8970B Error Displays cont d Error Messages Operation Error Messages and Recovery contd This display indicates that a measurement overflow has occurred or that the measure
5. 3 41 Receiving the Clear Lockout Set Local NMOSBAGO gt ooiey 2h ob cohiee sas VEN eee aeii 3 41 Receiving the Pass Control Message 3 41 ree gt Sending the Require Service Message 3 4 sedis 2l Enabling the Service Request Condition 3 41 ere 21 Sending the Status Byte Message 3 42 wees 2 1 Clearing the Status Byte 2 0 2 0 ccc cece ees 3 43 s 2 1 Sending the Status Bit Message 3 44 tees BL Receiving the Abort Message 6 3 44 22 HP IB Syntax and Characteristics seve 2 3 PINT BEY odara a EA ENE Se eee 3 45 sees OO Detailed Operating Instructions dens 23 Ca hprate sve s ie ci ue Get euewaataal E 3 59 ee 23 Calibration Frequency ccccceeuees 3 65 wera 283 Calibration IF Attenuators c e008 3 67 wees 23 Calibration Input Gain Selection 3 69 ii Rell d MA LAA RR Nd MIR RD CONTENTS cont d Page Page Controller Capability of the Preset Conditions and Power Up Sequence 3 205 Noise Figure Meter cccccccccceeees 3 71 Programming the System LO 3 210 Data Output to Oscilloscopes Recorders Programs Available to Control the and Plotters ccc ee rb yainaanebees 3 73 System LO uc Ma ticecieneess A ETES 3 219 Display Control cccccecccesceueas 3 81 RF Attenuation Selection 005 3 222 Display Resolution 0ccccecceceees 3 83 Seguente ardar coe a a ee Bes 3 224 Di
6. Coaxial Connectors Coaxial mating connectors used with the Noise Figure Meter should be 50 ohm BNC or type N male connectors 500 type N and APC 3 5 male coaxial connectors are used with the Noise Figure Test Set 2 11 Operating Environment The operating environment for the Noise Figure Meter should be within the following limitations Temperature 0 0c cece eeeee 0 to 55 C Humidity os ioscan edd ak en eo lt 95 relative Altitude lt 4570 metres 15 000 feet 2 12 Bench Operation The instrument cabinet has plastic feet and fold away tilt stands for convenience in bench operation The plastic feet are shaped to ensure self aligning of the Installation instruments when stacked with other HP equip ment The tilt stands raise the front of the instru ment for easier viewing of the front panel Table 2 2 ASCII Address Codes to Decimal Equivalents ASCII Address Codes Decimal LISTEN TALK Equivalents gt A gt ow Hos WM kK O gt B C D E F G H I J K L M N O P Q R S T U V W X Y Z N VEA 2 13 Rack Mounting The Noise Figure Meter weighs 18 5 kg 40 Lb therefore care must be exercised when lifting to avoid personal injury Use equipment slides when rack mounting Rack mounting information is provided with the rack mounting kits If the kits were not ordered with the instrument as options they may be ordered through the nearest Hewlett Packard
7. Lights Special Function Key Stored in Gon tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Noise Figure and Gain 7 0 A0 or 7 0SP N Test Pattern 1 Al or 7 1SP Noise Figure Only 2 A2 or 7 28P Gain Only 3 A3 or 7 3SP Off Off Off Off Off Off Cursor enabled for 4 A8 or 7 4SP oscilloscope display Cursor disabled for AQ or 7 5SP oscilloscope display Enter Oscilloscope Limits On On On Z ZZZZ teed mee bet e Z ZAZA LDZYy Off Off Off Noise Figure Lower 8 1 NLor8 amp 1SP N Y Y NC 0 0 Limit Noise Figure Upper 8 2 j NUor8 amp 2SP N Y Y NC 8 8 Limit Gain Lower Limit 8 3 IGL or8 35P N Y Y NC 0 0 Gain Upper Limit 84 GUor84SP N Y Y NC 40 40 Recorder Functions Go to Lower Left LL or 20 0SP N off Off Off Go to Upper Right UR or 21 0SP Off Off Off Plot Noise Figure A4 or 22 0SP Off Off Off Off Off Off Off Off Off Plot Gain 0 A5 or 23 0SP Strip Chart Mode 0 A6 or 24 0SP X Noise Figure Y Gain ZAZZZ Meg Z Z ZZZ Z 1Table categories are explained in the Special Function Detailed Operating Instruction 3 73 Operation HP 8970B Data Output to Oscilloscopes Recorders and Plotters contd Special Functions 7 8 and 20 through 25 Procedure contd Special Function Program Code Description cade c2 Piot
8. No sideband selection i required uniess Special Function 3 2 is used to find user LO frequency Sideband selection is required to calculate correct measurement signal or user LO fre quency when Special Function 3 2 is used HP 8970B Signal Comparison cont d indications Operation Measurement Modes cont d Special Function 1 Measurement Modes 1 2 and 1 4 the fixed system local oscillator frequency can be set to any point within the 10 to 99999 MHz range In Measurement Modes 1 7 and 1 9 the fixed user controlled local oscillator frequency can be set to any point necessary The limiting factors within each range are the frequency range of the local oscillator and the noise source There is no mixer used in Measurement Modes 1 0 and 1 5 Looking back into the mixer in Measurement Modes 1 1 1 3 1 6 and 1 8 the Noise Figure Meter passband translates into two sidebands Each sideband is separated from the local oscillator frequency by a fixed IF the receiving frequency of the Noise Figure Meter or Noise Figure Test Set As the local oscillator sweeps the sidebands move with it The frequency can beincreased or decreased within the allowable frequency range In Measurement Modes 1 2 1 4 1 7 and 1 9 the local oscillator frequency is held fixed As the variable IF sweeps the sidebands move away from the system local oscillator frequency in opposite directions for an increasing IF sweep and toward the local
9. Refer to Table 3 14 in the Special Functions Detailed Operating Instruction for a list of the Special Func tions that are turned off or not affected by the Clear Message 3 23 Receiving the Trigger Message When in remote and addressed to listen the Noise Figure Meter responds to a Trigger message by executing one measurement cycle The Noise Fig ure Meter responds equally to a Trigger message the Group Execute Trigger bus command GET and a Data message program code T2 execute a measurement 3 24 Receiving the Remote Message The Remote message has two parts First the remote enable bus contro line REN is held true second the device listen address is sent by the con troller These two actions combine to place the Noise Figure Meter in remote mode Thus the Noise Figure Meter is enabled to go into remote when the controller begins the Remote message but it does not actually switch to remote until addressed to listen the first time No instrument settings are changed by the transition from local to remote When actually in remote the Noise Figure Meter s 3 40 HP 8970B Noise Figure Meter front panel REMOTE annunciator lights When the Noise Figure Meter is being addressed whether in remote or local its front panel LISTEN or TALK annunciator turns on 3 25 Receiving the Local Message The Local message is the means by which the controller sends the Go To Local GTL bus com mand If addressed to l
10. The address of the Noise Figure Test Set is the one stored in the Noise Figure Meter Special Function 40 2 The address of the System Local Oscillator is the one stored in the Noise Figure Meter Special Function 40 1 The appropriate System Local Oscillator program Special Function 41 is active SYSTEM LOCAL OSCILLATOR OUTPUT 5599 goog 0 wM 000o m NOISE SOURCE DRIVE OUTPUT Figure 3 11 Noise Figure Measurement System Check Setup HP 8970B Operation OPERATOR S CHECKS Noise Figure Measurement System Check cont d Procedure cont d 10 11 12 13 NOTE Steps 4 through 9 will verify that the Noise Figure Test Set and the System Local Oscillator are properly connected to the Noise Figure Meter and that the Noise Figure Meter can talk to the Noise Figure Test Set and System Local Oscillator If steps 4 through 9 do not perform as indicated go to step 17 On the Noise Figure Meter press 1 5 SPECIAL FUNCTION Verify that 3000 and E28 are displayed Error code E28 can be ignored Press FREQUENCY and key in 100 Press ENTER Verify that the SSBi annun ciator on the Noise Figure Test Set is on Press FREQUENCY and key in 2000 Press ENTER Verify that the SSB2 annunciator on the Noise Figure Test Set is on and the LO is set to 2700 MHz Press FREQUENCY and key in 3000 Press ENTER Verify that the SSB3 annun ciator on the Noise Figure Test Set is on and the LO is
11. The left display shows each frequency at which a measurement is made The INSER TION GAIN display shows the gain of the DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency Calibrate Noise Figure Test Set YIG Filter Calibration Measurement Modes Sideband Selection Special Functions 3 159 Operation Description Requirements 3 160 HP 8970B Measurement Mode 1 6 Special Function 1 6 NOTES If the IF into the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator can be re duced below 1600 MHz Measurement Mode 1 1 is a better choice than Measurement Mode 1 6 Measurement Mode 1 1 requires less equipment less noise figure is contributed by the measurement system and a pre amplifier may not be required for the measurement Measurement Mode 1 6 requires the use of the HP 8971B Noise Figure Test Set a system local oscillator and a user controlled local oscillator Measurement Mode 1 6 uses two stages of frequency conversion The user controlled local oscillator and an external mixer provide the first stage of conversion The user controlled local oscillator is not controlled by the Noise Figure Meter the user controlled local oscillator must be controlled by the user The second stage of conversion is provided by the system local oscillator and the Noise Figure Test Set The Noise Figure Meter does cont
12. To display the smoothing factor key in 13 2 SPECIAL FUNCTION If a change is desired key in the new smoothing factor and then press the ENTER key The smoothing factor can also be changed from the front panel Press INCREASE for more smoothing or press DECREASE for less smoothing Each time one of these keys is pressed the smoothing factor changes by a factor of two To select exponential or arithmetic smoothing for fixed frequency measurements only key in the corresponding Special Function code and then press the SPECIAL FUNCTION key HP 8970B Operation Smoothing Averaging cont d Includes Special Function 13 Procedure cont d se de ge S5 EE Z FE ZE Special Function Program ae de a ea 2 5 gt 23 Code zg Ea 2 188 e s f O Bescription coe Gump 8 28 5 33 8 2 Exponential smoothing mode for fixed frequency measurements Arithmetic smoothing mode for fixed frequency measurements Displays and allows entry of smooth ing factor V0 or 13 0SP V1 or 13 1SP AF or 13 2SP Table categories are explained in the Specia Functions Detailed Operating Instruction Example To select exponential smoothing and a smoothing factor of 4 Code Function ocr OA GE keystrokes G T ereen a gt program codes les el Program Code lt 2 Parameter gt INCREASE IN DECREASE DE Smoothing Fact
13. b Special Function 48 0 must be active Noise Figure Meter is system controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 45 0 must be active Noise Figure Test Set enabled in measure ment modes 1 5 through 1 9 Special Function 45 0 is the default setting after using Special Function 0 9 or Special Function 45 1 Noise Figure Test Set enabled always must be active d The address of the Noise Figure Test Set must match the Noise Figure Test Set address that is stored in the Noise Figure Meter Use Special Function 40 2 Noise Figure Test Set System Interface Bus address to display and change this address if necessary The default address for the Noise Figure Test Set is 10 after using Special Function 0 9 3 183 Operation Requirements cont d Procedure 3 184 HP 8970B Measurement Mode 1 9 conta Special Function 1 9 e Special Function 46 0 must be active Enable system local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 f The address of the system local oscillator must match the address of the system local oscillator stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator System Interface Bus address to display and change this address if necessary The default address is 19 after using Special Function 0 9 g The correc
14. 10 dBm Input Power gt 65 dB Between noise source and HP 8970B RF Input Maximurm Net External Gain lt 0 03 dB change in measured noise figure Spurious Response For spurious levels below 45 dBm in the 10 to 2100 MHz range and 15 dBm in the 2 1 to 18 GHz range 1 Resolution over the Hewlett Packard Interface Bus is 0 001 dB 2 Peak to peak is defined as five times the standard deviation of a statistically valid set of readings Five standard deviations about the mean includes 99 of the readings for a Gaussian distribution 3 Resolution over the Hewlett Packard Interface Bus is 0 001 dB 4 Resolution over the Hewlett Packard Interface Bus is 0 01 dB 1 5 General Information HP 8970B Table 1 1 Noise Figure Meter Specifications 2 of 2 Characteristics Performance Limits Conditions INPUT contd Reducing System Noise Figure with Preamplification lt 1 8 dB noise figure of the external system Low noise external preamplification with net gain gt 20 dB ELECTROMAGNETIC COMPATIBILITY EMI Conducted and radiated interference is in compliance with MIL STD 461B Methods CE03 and REO2 CISPR publication 11 1975 and Messem pfaenger Postverfuegung 526 527 1979 Kennzeichnung Mit F Nummer Funkschutzeichen MIL STD 461B CISPR publication 11 and Messem pfaenger Postverfuegung 526 527 1979
15. Description Special Functions are off or set to their zero suffix mode The exception is Service cont d Request which is set to enable an HP IB code error to cause an SRQ Special Function 44 3 In addition default data values are set for the special functions listed in Table 3 13 Special Function 0 0 Special Function 0 0 initializes selected special functions It is similar to PRESET except that default data values are not set Existing values do not change Refer to Table 3 14 Special Function Summary in the Special Functions Detailed Operating Instruction for a complete list of Special Function 0 0 conditions Procedure To set the Noise Figure Meter to a known state press the PRESET key or key in 0 9 and press the SPECIAL FUN CTION key To initialize selected special functions key in 0 0 then press the SPECIAL FUNCTION key Example To initialize selected special functions LOCAL Function keystrokes e SPECIAL FUNCTION LHP i program codes Program Code Parameter cz Special Function 0 9 0 9SP PRESET Special Function 0 0 Program Codes indications After entering Special Function 0 9 or pressing PRESET the INSERTION GAIN display shows Fr and the NOISE FIGURE display shows CAL while a frequency calibration is performed After approximately five seconds the left display shows 30 MHz the INSERTION GAIN display is blank and the NOISE FIGURE display shows noise figure in units of F dB
16. Figure 2 3 Hewlett Packard Interface Bus and System Interface Bus Connections HP 8970B 2 14 RECORDING IF ATTENUATOR VALUES IF attenuator data is used to correct the gain readings during the gain measurement It is criti cal that the Noise Figure Meter know the value of its internal IF attenuators in order to meet its gain accuracy specification Recording these values ensures a backup record is kept if a nonvolatile memory failure should occur HP recommends that IF attenuator values be recorded in Table 4 1 when the Noise Figure Meter is turned on for the first time and after its annual calibration Table 4 1 is located in the Gain Measurement Uncertainty Performance Test in Section IV This performance test also includes a procedure for reading the IF attenuator values Refer to the Entering IF Atten uator Values portion of the performance test 2 15 STORAGE AND SHIPMENT 2 16 Environment The instrument should be stored in a clean dry environment The following environmental lim itations apply to both storage and shipment Temperature 05 55 C to 75 C H midity 5 5 iiadei teenagers lt 95 relative Altitude lt 15 300 metres 50 000 feet 2 17 Packaging Tagging for Service If the instrument is being returned to Hewlett Packard for service please com plete one of the blue repair tags located at the back of this manual and attach it to the instrument SYSTEM LOCAL OSCILLATOR
17. Special Function 40 There are two HP IB and six SIB System Interface Bus addresses The two HP IB addresses are really both addresses of the Noise Figure Meter One address is the address of the Noise Figure Meter The other address is called the Pass Through Address of the Noise Figure Meter The Pass Through Address is used when an externa controller on the Hewlett Packard Interface Bus HP IB wants to control a device on the System Interface Bus SIB The Pass Through Address is set up automatically by the Noise Figure Meter only after Pass Through Mode has been initialized using Special Function 40 6 or HP IB code PT The Pass Through Address is one greater than the Noise Figure Meter s address if it is even and is one less than the Noise Figure Meter s address if it is odd Refer to the System Interface Bus Control Detailed Operating Instruction for more information about Pass Through Mode and the Pass Through Address Special Function 40 7 can be used to display the Pass Through Address The six SIB addresses are listed below e System Local Oscillator e System Interface Bus e Noise Figure Test Set e Pass Through Device Plotter e Pass Control The System Local Oscillator is used with the Noise Figure Meter in Measurement Modes 1 1 through 1 4 and the Noise Figure Meter and Noise Figure Test Set in Measurement Modes 1 5 through 1 9 The Noise Figure Test Set is configured with the Noise Figure Meter in Measu
18. g Set up for a calibration with the DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction h Send the command RM 2EN RS CA Wait for a serial poll to return a non zero value indicating calibration is complete i Insert the DUT into the measurement system j Special Function 30 1 trigger hold must be active HP IB code is T1 k Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 l Set the system LO to the appropriate frequency Refer to the LO s operating manual for the required HP IB codes Allow sufficient time for the output of the system LO to stabilize m Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep HP 8970B Operation Measurement Mode 1 3 conta Special Function 1 3 Comments n Amethod must be determined when to step to a new frequency and read the noise cont d figure results This read operation cannot be completed until the new data is ready Itis possible to write an SRQ interrupt routine on the Data Ready SRQ Refer to Enabling the Service Request Condition paragraph 3 30 o Continue to loop through steps 1 m and n A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the frequency that was read from the Noise Figure Meter with the
19. Error code E38 is generated when the signal being input to the Noise Figure Test Set does not fall between 10 to 18000 MHz Check the parameter START FREQ STOP FREQ STEP SIZE Special Functions 3 0 or 3 1 and Special Functions 2 0 through 2 3 that may have caused E38 or do a PRESET and re enter the parameters Verify that the measurement signal falls between 10 to 18000 MHz 3 101 Operation Comments cont d 3 102 HP 8970B Error Messages and Recovery conta Error code E42 is generated when the System Local Oscillator is not found at the address specified with Special Function 40 1 Verify that the System Local Oscillator is connected to the SYSTEM INTERFACE BUS connector and not to the HEWLETT PACKARD INTERFACE BUS HP IB connector Also verify that the address of the System Local Oscillator is the same address that is specified with Special Function 40 1 If the Noise Figure Meter is not going to control the System Local Oscillator error E42 can be eliminated by using Special Function 46 1 Special Function 46 1 is retained in memory when the Noise Figure Meter is turned off The next time it is desired to have the Noise Figure Meter control the System Local Oscillator Special Function 46 0 will have to be active Error code E44 is generated when the Noise Figure Test Set is not found at the address specified by Special Function 40 2 Verify that the Noise Figure Test Set is connected to the SYSTEM INTERFACE BUS connec
20. HP B CONTROLLER Installation Original Packaging Containers and materials iden tical to those used in factory packaging are avail able through Hewlett Packard offices Mark the container FRAGILE to assure careful handling In any correspondence refer to the instrument by model number and full serial number Other Packaging The following general instruc tions should be used for re packaging with com mercially available materials a Wrap the instrument in heavy paper or plas tic If shipping to a Hewlett Packard office or serv ice center complete one of the blue tags and attach it to the instrument b Use a strong shipping container A double wall carton made of 2 4 MPa 350 psi test material is adequate c Use enough shock absorbing material 75 to 100 mm layer 3 to 4 inches around all sides of the instrument to provide firm cushion and prevent movement in the container Protect the front panel with cardboard d Seal the shipping container securely e Mark the shipping container FRAGILE to assure careful handling NOISE SOURCE Figure 2 4 Noise Figure Measurement System Interconnections 2 5 2 6 HP 8970B Operation SECTION Ill OPERATION 3 1 INTRODUCTION This section provides complete operating infor mation for the Noise Figure Meter Included in this section are both genera and detailed operat ing instructions detailed descriptions of the front and rear panel local
21. HP 8970B Operation Data Output to Oscilloscopes Recorders and Plotters contd Special Functions 7 8 and 20 through 25 Example b To display the test pattern on the oscilloscope screen press 7 1 SPECIAL FUNC cont d TION or send HP IB code A1 NOTE In the following step first adjust the position controls on the oscillocope to place the test pattern on the left side and the bottom Then adjust the gain controls to position the right side and top c Adjust the oscilloscope controls until the test pattern just fills the screen touching the outer lines on all four sides See figure below Verify that the vertical and horizontal lines cross near the center of the screen Test Pattern on Oscilloscope NOTE In the following steps it is assumed that the DUT has a noise figure range of 0 5 to 4 dB and a gain range of 0 to 25 dB over the specified frequency range d To display the noise figure and gain traces on the oscilloscope screen press 7 0 SPECIAL FUNCTION or send HP IB code A0 e Todisplay the noise figure lower limit in the left display press the front panel key GRAPHIC SCALE NOISE MIN or press 8 1 SPECIAL FUNCTION or send HP IB code NL If the left display shows the default value of 0 000 dB continue with the next step If the display shows a different value press 0 and ENTER or send HP IB code OEN f Todisplay the noise figure upper limit in the left display press the front panel key GRAPHIC SC
22. Use Logic Analyzer Input Lines 43 HP 1630A HP 1630D Timing Analysis 16 lines or HP 1631D Noise Source Power Required 28V_ HP 346B Option 001 ENR 15 2 dB or HP 346C Connector Type N male HP 1740A or HP 1980A Oscilloscope Measuring System HP 1980B or HP 54200A D Power Meter Uncertainty 0 02 dB HP 436A PAT Mode dB Relative Power Sensor Frequency Range 10 to 4000 MHz HP 8484A HP 8482A Power Range 0 1 nW to 10 aW or HP 8485A SWR 30 to 4000 MHz 1 15 Power Splitter Frequency Range 10 to 1600 MHz HP 11667A PA Oscilloscope Inputs 2 Channel A vs B or X vs Y and Z Axis Signal Generator Frequency Range 10 to 1600 MHz HP 8340B Sweep Osci l C T System LO Frequency Accuracy 1 kHz lator or HP 8672A or PA Output Level 13 dBm HP 8673B Synthesized Signal Generators Frequency Range 1380 to 2300 MHz Output Level 10 dBm Fundamental signal generator Signal Generator HP 8614A HP 5005A or HP 5005B or HP 5006A i Signature Because the signatures documented are unique to Multimeter a given signature analyzer no substitution is Analyzer recommended Spectrum Analyzer Frequency Range 10 to 1600 MHz HP 8565A or HP 8566A zs Sweep Oscillator Frequency Range 20 to 2400 MHz HP 8620C 86222B Attenuation 70 dB in 10 dB steps Option 002 or HP 8340B or HP 8350B SWR Bridge Frequency Range 10
23. gt 2 661 lt 3 758 for 5 dB attenuator For example Vrefl 0 986622 volts and Vavg 5 dB 0 312579 volts 0 986622 volts 0 312579 volts 3 15639 This value is within the stated limits On the Noise Figure Meter press 70 3 SPECIAL FUNCTION to switch in the internal 10 dB attenuator Take 10 voltmeter readings Using at least four digits to the right of the decimal point calculate and record the average of the readings Vavg 10 dB Compute the 10 dB attenuator value as shown Vrefl Vavg 10 dB _______ gt 8 414 lt 11 885 for 10 dB attenuator On the voltmeter select internal triggering If the voltmeter has filtering turn it off Reduce the 10 dB step attenuator by 10 dB and adjust the 1 dB step attenuator until the voltmeter reads as close to 1 volt as possible Select single triggering on the voltmeter If the voltmeter has filtering turn it on Take 10 voltmeter readings HP 8970B Performance Tests PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure contd 13 14 15 16 Lis 18 19 20 21 Using at least four digits to the right of the decimal point calculate and record the average of the readings This is the reference voltage for the 15 dB and 20 dB attenuator calculations Vref2 On the Noise Figure Meter press 70 4 SPECIAL FUNCTION to switch in the internal 15 dB attenuator Take 10 voltmeter readings Then calculate and record th
24. protect Noise Figure Test Set switches Section VHI Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 99 Operation Error Messages cont d Comments 3 100 HP 8970B Error Messages and Recovery cont d Error Volatile V or Code Nonvolatile NV Message Recommended Action Comments Noise Figure Test Set Errors cont d Noise Figure Test Set cannot Select Special Function 17 1 perform a single sideband measurement at this frequency Interpolating across the Ensure that the frequency of Noise Figure Test Set s interest is a calibrated point bands is not permitted The YIG filter temperature Repeat the procedure that was control loop will not lock used prior to error E105 being inside the Noise Figure Test generated Refer to Section VHI Set Service for the Noise Figure Meter or the Noise Figure Test Set Error code E19 can be generated for either a coarse or fine tuning calibration of the Noise Figure Test Set Check all cables and ensure thatthe LO INPUT RF INPUT and IF OUTPUT signal paths have been properly connected If the error occurs after another attempted calibration the Noise Figure Meter is unable to locate the Noise Figure Test Set s YIG filter passband If a fine tune calibration is being performed a coarse tune calibration may be needed A coarse tune calibration is needed when the Noise Figure Measurement S
25. up period is required for the tests Line voltage must be within 5 and 10 of nominal if the perfor mance tests are to be considered valid 4 2 EQUIPMENT REQUIRED Equipment required for the performance tests is listed in Table 1 5 Recommended Test Equipment in Section I Any equipment that satisfies the crit ical specifications given in the table may be sub stituted for the recommended model s 4 3 TEST RECORD Results of the performance tests may be tabulated on the Test Record at the end of the procedures The Test Record lists all of the tested specifica tions and their acceptable limits The results recorded at incoming inspection can be used for comparison in periodic maintenance and trouble shooting and after repairs or adjustments System performance is guaranteed if each instru ment in the system is calibrated 4 4 CALIBRATION CYCLE This instrument requires periodic verification of performance Depending on the use and environ mental conditions the instrument should be checked using the following performance tests at least once every year The instruments that are part of the HP 8970S Noise Figure Measurement System should be cali brated once a year 4 1 Performance Tests HP 8970B PERFORMANCE TESTS 4 5 TUNING ACCURACY PERFORMANCE TEST Specification Description Equipment Procedure TUNING ACCURACY from 10 to 40 C 1 MHz 1 of frequency 6 MHz maximum
26. 001 Calculator sesio Getcha ieee eset iseie HP 41C Digital Voltmeter c cece eee eee HP 3456A Filter Low Pass 4 60s 0080 bead dea eesees HP 360B Power Meter c2 sic chs 205 Siseeeereegaiss HP 436A Power Sensor 0ccccsereceeeeeeues HP 8484A Power Splitter cccceeceseeees HP 11667A Signal Generator 2 e0e eee eeeee HP 8340B Procedure 1 Connect equipment as shown in Figure 4 2 except do not connect the power sensor to the step attenuator 2 Turn on all equipment and allow it to warm up for one hour Set the signal generator for a 50 MHz continuous wave output at 17 dBm On the Noise Figure Meter set FREQUENCY to 50 MHz Key in 80 0 SPECIAL FUNCTION to display the noise power detector output in volts voltmeter mode Key in 31 1 SPECIAL FUNCTION to inhibit frequency calibrations Key in 60 5 SPECIAL FUNCTION to set the input gain to 20 dB Key in 70 6 SPECIAL FUNCTION to set the IF attenuation to 25 dB Set the smoothing factor to 4 using the INCREASE and DECREASE keys 5 Zero the power meter and set the 1 dB step attenuator to 10 dB Connect the power sensor to the 1 dB step attenuator as shown in Figure 4 2 HP 8970B Performance Tests PERFORMANCE TESTS NOISE FIGURE RANGE AND ACCURACY PERFORMANCE TEST cont d Procedure cont d 10 11 12 13 14 SIGNAL GENERATOR POWER METER RECORDER OUTPUT RF OUTPUT SENSOR STEP POWER ATTENUATOR SENSOR LOW PA
27. 3 145 Operation HP 8970B Measurement Mode 1 3 cont d Special Function 1 3 Procedure There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement un certainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selec tion Detailed Operating Instruction a Verify thatthe minimum requirements specified under Requirements are satisfied b Press 1 3SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 3 c Set frequency parameters including the fixed IF Special Function 3 0 d Calibrate in Mode 1 3 If a preamplifier will be used during the measurement the preamplifier must be used during the calibration e Insert DUT and initiate sweep Example To make a swept CORRECTED NOISE FIGURE AND GAIN measurement in the 3 0 to 4 5 GHz range in 20 MHz steps with a fixed IF of 70 MHz NOTE This example assumes that the Noise Figure Meter is acting as a con troller on the System Interface Bus and the minimum requirements specified under Requirements are satisfied Refer to Comments for a brief description of using an externa
28. 5 Exponential Smoothing Smoothing Averaging Q ty Arithmetic Averaging rt 3 Q ch w O Hs Z Q pow Smoothing Factor Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 3 241 Uperation HP Syv U0b Table 3 14 Special Function Summary 4 of 15 References and Description P Comments Lights Special Function Key Stored in Con tinuous Memory Can be Stored and Recalled Special Functions 0 0 Conditions Preset fand HP IB Clear Conditions Special Function 0 9 Conditions Manual A Cold Measurement Measurement SOURCE off Functions Manual Measurement Hot Measurement Functions SOURCE on Cold Calibration SOURCE off Hot Calibration SOURCE on Display Current _ Measurement Display Manual Measurement Results lt Z BZ we ne a x ee Display 3 Measurement frequency Control is displayed in left window Input to Noise Figure Meter Modes 1 0 through 1 4 or Noise Figure Test Set Modes 1 5 through 1 9 displayed Frequency display is blanked All displays are blanked Display Control Sideband j Single Sideband Sideband Frequency Operation Modes 1 5 Selection Offset through 1 9 Double Sideband Operation Modes 1 5 through 1 9 Upper and Lower side band crossover frequency selection Noise Figure Internal IF for SSB
29. Codes Comments For the oscilloscope recorder and plotter modes whatever is displayed in the NOISE FIGURE display is treated as a noise figure trace For example if Special Function 9is active the power measurement information displayed is output to the oscilloscope recorder or plotter as ifit were noise figure information Noise figure is displayed in the units selected by Special Function 10 and gain is displayed in dB Special Function 8 or the front panel Graphic Scale Keys are used to set both noise figure and gain limits Special Function 24 selects the strip chart mode This mode is useful in plotting noise figure and gain versus time For example it can be used to plot noise figure versus emitter current on an X Y recorder or to drive an external meter The X AXIS output is the noise figure information and the Y AXIS output is the gain information Related Display Units Selection Sections Measurement Modes 1 0 through 1 9 Special Functions 3 80 HP 8970B Description Procedure Operation Display Control Special Function 16 Special Function 16 allows the user to select the kind of information that will be shown by the left front panel display or to disable the front panel displays Special Function 16 0 enables the left display to display the measurement frequency In this mode the front panel displays function normally Special Function 16 1 enables the left display to display the IF into the Noise Fig
30. Comments An external controller cannot be used when Special Function 4 2 is active cont d The active function of Special Function 4 is not affected by PRESET Special Function 0 0 or the LINE switch Related Special Functions Sections System Interface Bus Control 3 72 HP 8970B Operation Data Output to Oscilloscopes Recorders and Plotters Description Procedure Special Functions 7 8 and 20 through 25 The Noise Figure Meter can output analog data to an oscilloscope an X Y recorder ora strip chart recorder The Noise Figure Meter can only be used with an analog oscilloscope Also digital data can be output to a plotter on the Hewlett Packard Interface Bus or the System Interface Bus However only one of these devices can be used at a time Since the setup procedures and operation are similar for all four devices the operating information for all are covered in this operating instruction Normally itis simpler to perform a setup procedure using the oscilloscope and then doa plot or switch to a recorder mode or use an oscilloscope camera if a permanent record is required In the example following the general procedure this type of setup will be shown To select one of the oscilloscope recorder or plotter output functions key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Special Function Program twin e gD Output to Oscilloscope On On On Off Off Off
31. Function 3 1 Mixer Yes variable frequency Receiver No Mixer Yes fixed fre quency set with Special Function 3 1 Receiver No Yes Variable frequency Yes Fixed frequency set with Special Function 3 1 Mixer Yes variable frequency Receiver No Mixer Yes fixed fre quency set with Special Function 3 1 Receiver No Special Function 2 1 Specia Function 2 2 Fixed IF into NF Meter set with Special Function 3 0 Variable IF into NF Meter Fixed IF into NF Meter set with Special Function 3 0 Variable IF into NF Meter Fixed IF into NF Test Set set with Special Function 3 0 Variable IF into NF Test Set Fixed IF into NF Test Set set with Specia Function 3 0 Variable iF into NF Test Set Single sideband signal up conversion IF measurement frequency LO frequency Special Function 2 3 An external filter is required for single sideband measurements N A Not Applicable 3 128 Sideband selection is required only if NF Meter controls System LO Double sideband is not allowed Sideband selection is required to calculate IF Sideband selection is required only if NF Meter controls System LO Sideband selection is required to calculate measurement frequency No sideband selection is required unless Special Function 3 2 is used to find user LO frequency Double sideband is not allowed Sideband selection is required to caiculate IF
32. Function EEE Data ELA Function meae SC lr Oe a gt TH9800EN pare ae i program codes Code ne Th Function For HP IB codes for Special Functions 5 and 6 refer to Procedure above The program code for ENTER is EN When Special Function 5 2 or 5 3 is active the current ENR or spot ENR is shown in the left display in units of dB If a new spot ENR value is entered it appears in the left display for as long as the ENTER key is depressed When Special Function 5 4 or 6 0 is active Tho or Teona is shown in the left display in the temperature unit selected by Special Function 11 If a new value is entered for either Thot Or Toona it appears in the left display for as long as the ENTER key is depressed 3 255 Operation HP 8970B Spot ENR Thot Teotia and ENR Table Selection contd indications cont d Related Sections 3 256 Special Functions 5 and 6 When Special Function 5 5 is active the left display shows five digits No units are displayed When Special Function 5 6 is active the left display shows the ENR identification number of one of the ENR tables The right display shows the ENR table number and the number of entries in the table When Special Function 5 7 or 5 8 is active the left display shows the number of the table that is currently being used for calibration or measurement If a new table number is entered for calibration or measurement it appears in the left display for as long a
33. HP 8340B 8341B Sweep Oscillator Special Function 41 4 e custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or output power wwe HP 897UBK Operation Measurement Mode 1 4 conta Special Function 1 4 Description Use Special Function 42 to define a new program for other system local oscillators cont d Procedure There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement un certainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selec tion Detailed Operating Instruction a Set frequency parameters including the fixed frequency for the system LO Spe cial Function 3 1 b Press 1 4 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 4 c Calibrate in Mode 1 4 this is only required fora CORRECTED NOISE FIGURE AND GAIN measurement If a preamp
34. HP IB code is T0 e The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes f Set the user controlled local oscillator to the appropriate frequency Refer to the local oscillator s operating manual for the required HP IB codes Allow sufficient time for the output of the local oscillator to stabilize g Perform a Noise Figure Test Set Fine Tuning Calibration and a Noise Figure Measurement System Calibration with the DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction and the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction HP 8970B Comments cont d Related Sections Operation Measurement Mode 1 9 contd Special Function 1 9 h Send the command RM 2EN RS CA Wait for a seria poll to return a non zero value indicating calibration is complete i Insert the DUT into the measurement system j Special Function 30 1 trigger hold must be active HP IB code is T1 k Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 1 Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep m A method must be determined when to
35. In addition the INSERTION GAIN display is blank HP 8970B indications cont d Comments Retated Sections Operation Noise Figure Uncorrected and Noise Figure and Gain Corrected cont d When the instrument is making noise figure and gain measurements the COR RECTED LED above the NOISE FIGURE AND GAIN key is illuminated The gain of the device under test DUT appears in the INSERTION GAIN display and the noise figure of the DUT appears in the NOISE FIGURE display For CORRECTED NOISE FIGURE AND GAIN measurements it is necessary to calibrate the instrument each time there is a change in measurement modes equipment except the DUT or frequency parameters if the new frequency parameters are outside of the calibrated range UNCORRECTED NOISE FIGURE and CORRECTED NOISE FIGURE AND GAIN measurements are always corrected for Teojg and ENR Measured noise can be expressed in a variety of units F F dB Y Y dB and Te K Refer to the Display Units Selection Detailed Operating Instruction for additional information The noise figure measurement range is 0 to 30 dB The gain measurement range for total noise figures less than 30 dB is 20 to at least 40 dB for the Noise Figure Meter ai a wala E RE Eg en N Ppa An tmy bleh aan 3 as nad weber cor le High measurement system noise figure leads to high measurement uncer tainty when measuring low gain devices A low noise preamplifier between the device under tes
36. Interface Bus Controller System Interface Bus Control Disable controller collision on the System Interface Bus error E48 Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 3 247 Operation HP 8970B Table 3 14 Special Function Summary 10 of 15 References and Description Comments Lights Special Function Key Stored in Con tinuaus Memory Can be Stored and Recalled Special Functions 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Disable Auto Pass System Interface Control on the Control on the System Control System Interface Bus Interface Bus Enable Auto Pass Control on the System Interface Bus Noise Figure Meter releases control of the System Interface Bus Noise Figure Meter takes control of the System Interface Bus Noise Figure Meter does a serial poll on the System Interface Bus Enable a selective device clear of the Pass Through Device on the System Interface Bus Enable a device clear on the System Interface Bus ifthe Noise Figure Meter is the active controller Enable an interface clear on the System Interface Bus if the Noise Figure Meter is the system controller Scan Special Function Special Function Catalog Lines Catalog Line 1 Status Line 2 Status Line 3 Status Line 4 Status Line 5 Status Most Spe
37. NOISE FIGURE UNCORRECTED Noise Figure Uncorrected and Noise Figure and Gain Corrected Noise Figure Uncorrected and Noise Figure and Gain Corrected Preset Conditions and Power Up Sequence Store and Recall ZO Zr Z BAr lt NOISE FIGURE AND GAIN CORRECTED PRESET RECALL GRAPHIC SCALE Noise Min Y Data Output to Oscilloscopes Recorders and Plotters Noise Max Y Data Output to Oscilloscopes Recorders and Plotters Gain Min Y Data Output to Oscilloscopes Recorders and Plotters Gain Max Y Data Output to Oscilloscopes Recorders and Plotters SEQ Sequence SINGLE Sweep N Sweep SPECIAL FUNCTION Special Functions START FREQ Y Sweep STEP SIZE Y Sweep STOP FREQ Y Sweep STORE Sweep and Calibrate Off must be used to turn these functions off over the HP IB Y Yes N No NC No Change Not Applicable Store and Recall Sweep 3 206 HY sy up Includes Special Functions 0 0 and 0 9 Operation Preset Conditions and Power Up Sequence conta Table 3 13 Special Function 0 9 and Preset Default Values for Special Functions Addresses HP IB and SIB Noise Figure Meter System Local Oscillator Noise Figure Test Set Plotter System Interface Bus oo Control LO Frequency Loss Compensation Before DUT Temperature of Losses After DUT Measurement Mode 1 1 Measurement Mode 1 2 and Measurement Made 1 3 Start Frequency
38. Noise Figure Test Set Control System Local Oscillator Control Plotter Control SIB Controller Sharing Control on the SIB Special Function Catalog RF Attenuation Selection 44 6 44 7 44 8 44 9 45 0 45 1 45 2 46 0 46 1 47 0 47 4 48 0 48 1 48 2 49 0 49 1 49 2 49 3 49 4 49 5 49 6 60 4 Q6 RM Q8 RE SB DD DS IS Description Enable Instrument Error to cause an SRQ Enable all desired Conditions on the Status Byte to Cause an SRQ Enable Extended Status Byte to Cause an SRQ Enable all desired Conditions on the Extended Status Byte Enable Noise Figure Test Set in Modes 1 5 through 1 9 Enable Noise Figure Test Set in all Modes Disable Noise Figure Test Set in all Modes Enable System Local Oscillator on the SIB Disable System Local Oscillator on the SIB Plotter is on the SIB Enable Plot Data to be read on the HP IB Enable Noise Figure Meter as System Controller on the SIB Disable Noise Figure Meter as System Controller on the SIB Disable Error 48 48 Disable Auto Pass Control Enable Auto Pass Control Enable Noise Figure Meter to Release Control of the SIB Enable Noise Figure Meter to Take Contro of the SIB Enable Noise Figure Meter to perform a Seria Poll on the SIB Perform a Selective Device Clear of the Pass Through Device on the SIB Perform a Device Clear on the SIB if the Noise Figure Meter is the Active Controller Perform an Interface Clear on the SIB if the Noise
39. Special Function 49 5 performs a selective device clear of the pass through device on the System Interface Bus This task will be done before the next HP IB read of the Noise Figure Meter can be done q Special Function 49 6 performs a device clear on the System Interface Bus if the Noise Figure Meter is the active controller This task will be done before the next HP IB read of the Noise Figure Meter can be done r Special Function 49 7 performs an interface clear on the System Interface Bus if the Noise Figure Meter is the system controller All instruments on the System Inter face Bus are unaddressed to listen or talk This task will be done before the next HP IB read of the Noise Figure Meter can be done To select one of the System Interface Bus Control special functions key in the corre sponding Special Function code and then press the SPECIAL FUNCTION key a o z S Z5 amp Tmn cS e T Se ae Se e R S Z S amp aa uct m O x ta oe S am D wu e ee Se 22 43 25 58 23 2 bannas o Special Function Program 2 84 28 58 Bee 28 de Belee eel ES fF E s sce a Se a a ad bie oz a w A co a Co tA Enable Noise Figure Test Set in Measurement Modes 1 5 through 1 9 Enable Noise Figure Test Set in all Measurement Modes Disable Noise Figure C Description Code lt Test Set in all 45 0 Measurement Modes 1 Table categories are explai
40. Stop Frequency Step Size Noise Figure Measurement System Internal IF SSB2 IF SSB3 IF DSB IF Oscilloscope Limits Noise Figure Lower Limit Noise Figure Upper Limit Gain Lower Limit Gain Upper Limit Plotter Functions Noise Pen Gain Pen Plot Title Programming the System Local Oscillator Power Level Set Sequence Smoothing Factor Spot ENR System Local Oscillator Side band Crossover frequency Measurement Modes 1 5 through 1 9 Teold Spot Thot Special Function 40 0 40 1 40 2 40 3 40 4 40 5 3 0 34 2 34 3 34 4 1 1 1 2 1 3 19 2 19 3 19 4 8 1 8 3 8 4 25 3 25 4 25 5 42 5 35 2 13 2 5 3 17 2 6 0 5 4 Preset Default Value 30 MHz Modes 1 1 and 1 3 3500 MHz Modes 1 6 and 1 8 10000 MHz Modes 1 2 and 1 4 44000 MHz Modes 1 7 and 1 9 0 dB OK 0 dB 8000 MHz 12000 MHz 200 MHz 700 MHz 450 MHz 25 MHz 0 8 0 40 1 2 HP 8970B Noise Figure Meter 6 dBm 1 9 1 15 2 dB 16 GHz 296 5K 9893K Special Function 0 9 Default Value 8 18 10 5 8 16 30 MHz Modes 1 1 and 1 3 3500 MHz Modes 1 6 and 1 8 10000 MHz Modes 1 2 and 1 4 44000 MHz Modes 1 7 and 1 9 0 dB OK 0 dB 8000 MHz 12000 MHz 200 MHz 700 MHz 450 MHz 25 MHz 0 8 0 40 1 2 HP 8970B Noise Figure Meter 6 dBm 1 9 1 15 2 dB 16 GHz 296 5K 9893K 3 207 Preset Conditions and Power Up Sequence conta includes Special Functions 0 0 and 0 9
41. The Noise Figure Meter is tuned to the frequency where accuracy is to be tested The point of maximum IF signal level is found by stepping the signal source through the passband while monitoring the level at the internal noise power detector A power reference is set and the 3 dB passband frequencies are determined The tuned center frequency of the Noise Figure Meter is then found as the average of the 3 dB frequen cies This tuned frequency is compared to limits derived from the specifications above Signal Generator 0 csc eee eeees HP 8340B 1 Connect the signal generator RF output to the Noise Figure Meter INPUT 2 Turn on the equipment and allow it to warm up for one half hour Set the signal generator output level to 30 dBm 8 On the Noise Figure Meter key in 31 2 SPECIAL FUNCTION to execute a fre quency calibration then key in 31 1 SPECIAL FUNCTION to inhibit any further frequency calibrations Key in 10 2 SPECIAL FUNCTION to set the display units to read Y Factor in dB 4 Tune both the Noise Figure Meter and the signal generator to 10 MHz 5 On the Noise Figure Meter key in 80 0 SPECIAL FUNCTION to display the noise power detector output in volts Key in 62 0 SPECIAL FUNCTION to hold the RF attenuators Key in 72 0 SPECIAL FUNCTION to hold the IF attenuators 6 Tunethesignal generator up and down in 100 kHz steps until the maximum voltage display on the Noise Figure Meter is located The 3 dB point should be with
42. Y Yes NC No Change Not Applicable lt Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 249 Operation HP 8970B Table 3 14 Special Function Summary 12 of 15 bcd gt E 5 Se Se Buse Si Be sziSss2isei se 5E Special Function agistlsaes 5S 2s T a2 w2 egas T2 ss References and Description kE e Ss mia 5 S2 sp 8o 3 8o Comments CAS a e ln Ae ac Noise Figure Enable a coarse calibra Noise Figure Test Set YIG tion of the Noise Figure Test Set YIG Filter Coarse Test Set Filter Calibration Selects the upper Calibration frequency of the Noise Figure Test Set IF Attenuation Selection IF Attenuation Selection MG MS KKK KG Ze ZAAAAAAADWNW Z2 4242424222424 24 Display IF Attenuator Settings IF Attenuation Selection Display IF Attenuators Off N Off Off Off IF Attenuators are held in the configuration that exists when Special Func tion 72 0 is activated IF Attenuator Hold Voltmeter 80 0 VC Mode 81 0 VH Recorder Test Functions IF Attenuation Selection Noise Source Off Noise Source On Refer to Section VIII Service Enable Recorder Test X Axis Test Y Axis Test Refer to Section VIII Service QO Q O O R oR O O R R Most
43. cont d Measurement Mode 1 5 Measurement Mode 1 6 Measurement Mode 1 7 Measurement Mode 1 8 Measurement Mode 1 9 Noise Figure Test Set YIG Filter Calibration Power Measurements Preamplifier Selection Preset Conditions and Power Up Sequence Programming the System LO Programs Available to Control the System LO RF Attenuation Selection Sequence Sideband Selection Smoothing Special Function Catalog Spot ENR Thos Teog and ENR Table Selection System Interface Bus Control Temperature Units Selection Trigger Selection 3 237 3 238 HP 8970B Operation Table 3 14 Special Function Summary 1 of 15 ao a se e 7S 5 T u amp n SSE Pg S E 28 gx S2 PE ES SS Special Function jeles oats ES tS 9S5 esl us zal ss References and Description ES SF ee ec E es Nan BES SEISE Bol SB Sa Comments ame wud li COTS 16D ce Aao a ES gt e Initialize 0 0 CS Initializes many Special Preset Condi Special Functions tions and Power Functions 09 Initializes or sets defaults Up Sequence for all Special Functions Measurement 1 0 EO Mode 1 0 10 1600 MHz Mode Selection measurement Noise Figure L1 El Mode 1 1 fixed IF Meter Y i Y On On On Measurement Mode 1 0 Y Y Offi Off Off Measurement variable freq sys LO Mode 1 1 N N 1 2 E2 Mode 1 2 variable IF Ni Y Y IO Off Off Measurement fixed freq sys LO SSB Mode 1 2 N 1 3 E3 Mod
44. keystrokes a B Ta E e SPECI lt 2 program codes Program For HP IB codes refer to Procedure above Codes a gt 3 69 Operation Comments Related Sections 3 70 HP 8970B Calibration Input Gain Selection contra Special Function 32 The gain settings other than the default values are used primarily when the Noise Figure Meter is calibrated with high gain external to the Noise Figure Meter If external gain is not being used during calibration and Special Function 32 1 is active error code E27 too much loss while calibrating may be generated If external gain is not being used during calibration and Special Function 32 2 or 32 3 is active error code E27 will be generated DUTs in the specified range of 20 to 40 dB can be measured using Special Function 32 0 Calibrate Special Functions HP 8970B Operation Controller Capability of the Noise Figure Meter Description Procedure Example indications Comments Special Function 4 The Noise Figure Meter can be used as a limited controller for an external device connected to the HP IB connector This capability is limited to operating in the Talk Only Mode outputting data to a recording device such as a printer The Noise Figure Meter can also be controlled by an external controller when Special Function 4 0 is active Only one of the two capabilities can be active at any one time To select an HP IB control capability ke
45. office Refer to the paragraph entitled Mechanical Options in Section I 2 3 Installation HP 8970B 1 SIGNAL GROUND PO TWISTED PAIR WITH 11 PO TWISTED PAIR WITH 10 SHOULD BE GROUNDED P O TWISTED PAIR WITH 9 AE a Aa gt P O TWISTED PAIR WITH 8 TWISTED PAIR PPO TWISTED PAIR WITH P O TWISTED PAIR WITH 6 REN DIOS DIO DIO 6 DIOS SHIELD CONNECT T0 pes GROUND ISRO liec RI NRFD DAV 0 DIO4 DIO3 D102 DICI ot to fro Line Ld ime od oe som tent om Lead om bas f gor Top Cei a A af DRBHROUHPBRE ISOMETRIC ___ _ THREAD M35 x 0 6 J 24 PIN MICRO RIBBON ISERIES 571 CONNECTOR Logic Levels The Hewlett Packard Interface Bus and System Interface Bus Logic Levels are TTL compatible i e the true 1 state is 0 0 Vde to 0 4 Vdc and the false 0 state is 2 5 Vde to 5 0 Vde Programming and Output Data Format Refer to Section IT Operation Mating Connector HP 1251 0293 Amphenol 57 30240 Mating Cables Available HP 10833A 1 metre 3 3 ft HP 10833B 2 metres 6 6 ft HP 10838C 4 metres 13 2 ft HP 10833D 0 5 metres 1 6 ft Cabling Restrictions 1 A Hewlett Packard Interface Bus system or System Interface Bus system may contain no more than 2 metres 6 6 ft of connecting cable per instrument The maximum accumulative length of connecting cable for any Hewlett Packard Interface Bus system or System Interface Bus system is 20 0 metres 65 6 ft
46. s NOISE SOURCE DRIVE OUTPUT Turn on all equipment and allow it to warm up for a half hour Zero and calibrate the power meter and sensor Set the 10 dB step attenuator to 70 dB and connect the equipment as shown in Figure 4 3 DIGITAL VOLTMETER POWER METER RECORDER OUTPUT AMPLIF TER NOISE SOURCE Figure 4 3 IF Attenuator Calibration Setup On the Noise Figure Meter press 70 1 SPECIAL FUNCTION to set the IF attenuators to 0 dB 60 1 SPECIAL FUNCTION to set the RF attenuators to 20 dB Put the power meter in range 3 Do not allow the power meter to autorange For the HP 436A Power Meter adjust the 10 dB and the 1 dB step attenuators until the power meter reads 45 dBm Press RANGE HOLD to set the power meter to RANGE 3 Adjust the step attenuators for a voltmeter reading as close to 1 volt as possible On the voltmeter select single triggering If the voltmeter has filtering turn it on Take 10 voltmeter readings Using at least four digits to the right of the decimal point calculate the average of the readings On the HP 3456A Digital Voltmeter press FILTER on to enable the analog filter 10 STORE 6 to store 10 readings per trigger SINGLE to select the single trigger mode MATH 2 to turn on the statistical math mode and SINGLE to trigger 10 voltmeter readings When the voltmeter has finished taking the 10 readings press RECALLO to recall the average of the readings 4 1 Performance Te
47. the measurement results for each mode can be displayed on an oscilloscope or output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement uncertainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selection Detailed Operating Instruction a Set frequency parameters b Calibrate in Mode 1 0 this is only required for a CORRECTED NOISE FIGURE AND GAIN measurement c Insert DUT and measure To make a swept CORRECTED NOISE FIGURE AND GAIN measurement in the 100 to 150 MHz range in 1 MHz steps a Press PRESET or send HP IB code PR to establish initial conditions This sets the Noise Figure Meter to Measurement Mode 1 0 b Set the frequency parameters for both the calibration and measurement c Enter actual ENR for the Noise Source if this has not previously been done LID ea7nn HP 8970B
48. the two 4 MHz passbands that are 2000 MHz apart might easily be useless data The frequencies displayed in the left display for various measurement conditions are shown in the following table The displayed frequency depends upon the measurement mode used and the sideband selected Special Function 2 In Measurement Mode 1 0 and 1 5 no external conversion is performed so the left display represents the measurement signal Fama In Measurement Modes 1 1 through 1 4 and 1 6 through 1 9 conversion is performed thus creating an external IF The Noise Figure Meter Noise Figure Measurement System is tuned to this IF while the system user controlled local oscillator is tuned to Fio 3 129 Operation 3 130 For Measurement Modes 1 1 1 3 1 6 and 1 8 ENTIRE SPECTRUM MOVES WITH SWEEPING LO ALERT a POWER FIXED IF FIXED IF 4 NOISE SOURCE ENR E i x ah PESONEN VEN ETE N O 2000 Fio IF Fio FigtlF 18600 FREQUENCY MHz sa NOISE POWER FROM NOISE SOURCE WHEN ON For Measurement Modes 1 2 1 4 1 7 and 1 9 POWER 2000 Fin 1600 F n IF LO 18000 O FIXED Fio l i SWEEPING IF SWEEPING IF ee l i l i l NOISE SOURCE ENR ee ee a Sa EERS F Fi 9 1600 18060 18000 Fio Fro Foci Fiort FREQUENCY MHz E NOISE POWER FROM NOISE SOURCE WHEN ON EES VARIABLE INTERMEDIATE FREQUENCY TUNING RANGE Noise Figure Meter Measurement Passband HP
49. 0 dB then the frequency should be noted However a reading of 13 0 dB indicates a return loss well within specifications 6 For each frequency noted in step 5 tune the Signal Generator and the Noise Figure Meter to that frequency Disconnect the SWR bridge from the Noise Figure Meter INPUT and set a power meter reference Reconnect the SWR bridge to the Noise Figure Meter INPUT The power meter should read greater than 11 73 dB below the reference 4 4 HP 8970B Performance Tests PERFORMANCE TESTS INPUT SWR PERFORMANCE TEST cont d Procedure 3 cont d INPUT SWR PERFORMANCE TEST Min Actual Max 20 dB Input Gain Setting Frequency MHz el tas j1 73 dB MHz Sh geen 11 73 dB MHz Baas 11 73 dB 10 dB Input Gain Setting Frequency MHz peer eet 11 73 dB MHz Sea Oe TORS 11 73 dB MHz ON EEEE 11 73 dB 0 dB Input Gain Setting Frequency MHz goose tare 11 73 dB MHz skied 11 73 dB MHz a 11 73 dB 7 Onthe Noise Figure Meter key in 60 2 SPECIAL FUNCTION to set the input gain to 10 dB Repeat steps 4 through 6 8 On the Noise Figure Meter key in 60 3 SPECIAL FUNCTION to set the input gain to 0 dB Repeat steps 4 through 6 4 5 Performance Tests HP 8970B PERFORMANCE TESTS 4 7 NOISE FIGURE RANGE AND ACCURACY PERFORMANCE TEST Specification NOISE FIGURE MEASUREMENT CHARACTERISTICS Range 0 0 to 30 dB Instrumentation Uncertainty 40 1 dB for a noise source in a 0 to 55 C in a 300K environment with
50. 122 HP 8970B Manual Measurement Functions cont d Special Functions 14 and 15 The following example is a general procedure for making manual measurements It may be necessary to determine the requirements of a specific application and make the necessary changes to obtain the best measurement results For example it is possible to make manual measurements using an external controller Additional information on this method is contained in the Comments section of this instruction Find and Hold the RF Attenuation a Enter the required parameters for the Measurement Mode that is going to be used b Connect the hot noise source to the DUT input Connect the DUT output to the measurement system setup c Press 14 2 SPECIAL FUNCTION to obtain the noise power d Press 6 2 0 SPECIAL FUNCTION to hold the RF attenuation setting The RF attenuation is held at this setting for the entire measurement Calibrate e Remove the DUT and connect the hot noise source to the measurement system setup f Press 14 4 SPECIAL FUNCTION to calibrate the measurement system for the hot noise source g Press 72 0 SPECIAL FUNCTION to hold the IF attenuation setting h Press 1 4 3 SPECIAL FUNCTION to store the hot noise source calibration reading and to select the cold noise source calibration Note that while the cold noise source calibration is selected the results are not stored until after the cold noise source is connected and Special Function 1
51. 16 HP 8970B SWEEP AURRE SRNL Frequency Function Keys in addition to the func tions described below the following keys are used to prefix numeric entries for the specified functions START FREQ STOP FREQ STEP SIZE FREQ and FREQ INCR Frequency is entered in MHz from the front pane Frequency parameters are entered ina Function Data ENTER format FIXED FREQUENCY Keys FREQUENCY Key Causes the tuned frequency to appear in the left display This key also acts as a clear key when an error is made during entry that is it returns the instrument to the measurement frequency Also see Frequency Function Keys FREQ INCR Key Causes the programmed frequency increment to appear in the left display while the key is depressed Also see Frequency Function Keys lt or keys Increase or decrease the tuned fixed frequency by the programmed frequency increment Holding either of these keys down causes the tuning to step continuously up or down SWEEP Keys SINGLE Key Starts one sweep from START FREQ to STOP FREQ in increments determined by STEP SIZE Operation PEU FIXED FREQ DENO At the end of one sweep the instrument remains tuned to the stop frequency Single sweep can be terminated by pressing the SINGLE key a second time AUTO Key Starts a sweep from the current fre quency The sweep repeats from START FREQ to STOP FREQ in increments determined by STEP SIZE until terminated Auto
52. 240V OPERATION PLUG NEMA 6 15P CABLE HP 8120 0698 220 240V OPERATION PLUG BS 1363A CABLE HP 8126 1351 The number shown for the plug is the industry identifier for the plug only The number shown for the cable is an HP part number for a complete cable including the plug Figure 2 2 Power Cable and Mains Plug Part Numbers 2 2 HP 8970B Table 2 1 Noise Figure Meter Factory Set Addresses Noise Figure Meter Plotter System Interface Bus Noise Figure Test Set Pass Control Device System Local Oscillator 2 8 Interconnections Interconnection data for the Hewlett Packard Interface Bus HP IB and the System Interface Bus SIB is identical See Figure 2 3 2 9 HP 8970S Noise Figure Measurement System The HP 8970S Noise Figure Measurement System consists of the Noise Figure Meter the Noise Figure Test Set and a System Local Oscillator Interconnection data for the Noise Figure Mea surement System is provided in Figure 2 4 If the System Local Oscillator is a free running source a coarse tune calibration must be performed Refer to the Noise Figure Test Set YIG Filter Calibration detailed operating instruction in Section III for the coarse tune calibration procedure The coarse tune calibration is not needed if a synthesizer is used for the local oscillator 2 10 Mating Connectors Interface Connector The HP IB and SIB mating connector is shown in Figure 2 3 Note that two securing screws are metric
53. 28 Special Function Program Se g 28 23 Code 23 s t g8 25 28 Description Code C 25 8218 Ee S g Measurement Mode 1 0 EO 1 0 10 to 1600 MHz Measurement Mode 1 1 El 1 1 variable fre quency system LO fixed IF Measurement Mode 1 2 E2 N Y Y Off Off Off 1 2 fixed frequency system LO varia ble IF SSB Measurement Mode 1 3 E3 N Y Y Off Off Off 1 3 variable fre quency system LO fixed IF mixer in DUT Measurement Mode 1 4 E4 N Y Y Off Off Off 1 4 fixed frequency system LO varia ble IF mixer in DUT Measurement Mode 1 5 E5 N Y Y off Off Off 1 5 10 to 18000 MHz Measurement Mode 1 6 E6 N Y Y Off Off Off 1 6 variable fre quency user control led LO fixed IF Measurement Mode 1 7 E7 N Y Y Off Off Off 1 7 fixed frequency user controlled LO variable IF SSB Measurement Mode 1 8 E8 N Y y Off Off Off 1 8 variable fre quency user control led LO fixed IF mixer in DUT Measurement Mode 1 9 E9 N Y Y Off Off Off 1 9 fixed frequency user controlled LO variable IF mixer in DUT Table categories are explained in the Special Functions Detailed Operating Instruction 3 125 Operation Description cont d 3 126 HP 8970B Measurement Modes conta Special Function 1 The following definitions will be helpful when using the different Measurement Modes System Local Oscillator The System Local Oscillator is used in Measurement Modes 1 1 through 1 9 is connected to
54. 40 6SP Display the Noise 40 7 VP or N N N NC NC Off Figure Meter s Pass 40 7SP Through Address Table categories are explained in the Special Function Detailed Operation Instruction Exampie To display the system LO address and change it to 20 LOCAL mance COE naom Function ama Data awa Function keystrokes 7 0O00 fm T HP IB 4 EA20EN ele E program codes Code py Function Program The program code to display the SIB address of the system LO is EA The system LO Codes address can be changed by entering a decimal number from 0 to 30 and then EN the a gt program code for ENTER The other addresses are changed in a similar manner The HP IB address of the Noise Figure Meter cannot be read or changed over the HP IB 3 115 Operation HP 8970B HP IB and System Interface Bus SIB Addresses contd Special Function 40 Indications The HP IB or SIB address of the corresponding special function appears in the left display when Special Function 40 is selected When an address is changed the new address appears in the left display for as long as the ENTER key is depressed When the ENTER key is released the instrument returns to the last selected measurement Comments Do not set the Noise Figure Meter address equal to any of the other addresses Related Controller Capability of the Noise Figure Meter Sections Remote Operation HP IB Special Functions 3 116 HP 8970B Operation IF Attenuation Selection Special Fu
55. 5 and 6 using a larger number of points Also make sure the noise source is properly connected to the INPUT connector dB Set the smoothing to 64 by pressing the SMOOTHING INCREASE key until 64 appears in the left display Repeat steps 5 and 6 but allow 10 seconds after triggering the reading before recording the data 0 Multiply the standard deviation by 5 The result should be lt 0 02 dB Ifthe result is gt 0 02 dB perform steps 5 and 6 using a larger number of points Also make sure the noise source is properly connected to the INPUT connector dB 4 23 Performance Tests HP 8970B 4 24 330 348 350 368 370 388 398 400 418 420 430 440 458 460 478 480 490 508 518 520 Automated Jitter Performance Test for HP 9826 36 with BASIC 2 0 PRINTER IS 70 Direct output to printer PRINT SPEC LIMIT HP 8972B JITTER DIM Point 1 gt OUTPUT 788 PR 13 1SP 13 25P 1EN 10 2 SP FRI QMZ ETETE ES RHEE REE HEHEHE REE EERE ERE HHE HEHEHE REE EERE ERR EE RHEE EHRHRENHEEREDH Set HP 8970B for arithmetic smoothing with N display Y factor in dB set frequency to 100 MHz ERR E RE REE EE HERE EERE HEH ER EEH EEE EE EER HE RHE HEKREHHEEEKEEEEE KER EREEREE YE i N 1090 Set number of samples for avg Spec 15 t Spec limit with smoothing Starttest t Quantity Initialize variables Total 2 LEER EEE REE EEE RAE REE HEE EERE RHEE KEE HERE EEE HERHR EEE REE EEREHREEEREEEEAHREER
56. 5 through 1 9 displayed A8 Oscilloscope display cursor enabled D i Step down A9 Oscilloscope display cursor disabled DP Disable Auto Pass Control BD All displays are blanked DS Perform a Device Clear on the System BF Left display is blanked Interface Bus if the Noise Figure Meter is BO Double Sideband the Active Controller Bl Lower Single Sideband DT Enable Display Test B2 Upper Single Sideband B3 Signal Up Conversion Noise Source Temperature Units for IF Feignal FLO Data Input B4 Noise Figure Test Set single sideband DO operation Modes 1 5 through 1 9 D1 B5 Noise Figure Test Set double sideband D2 F operation Modes 1 5 through 1 9 EA Display and Enter System LO SIB CA CALIBRATE Address eee CC Cold Calibration Manual Measurement EC ENR Table for Calibration CF Upper and lower sideband crossover EG Enable Interpolated Measurements in frequency selection Modes 1 5 through 1 9 Modes 1 5 through 1 9 CH Hot Calibration Manual Measurement Noise Figure Meter YIG Filter Tuning CI Calibrate IF Attenuators Punciona CP Noise Figure Test Set Coarse Tuning EH Enable Hysteresis Calibration when Calibration Frequency is Changed CR Noise Figure Meter releases control of the EM ENR Table for Measarement System Interface Bus EN ENTER CS Initialize Special Functions EP Enable Auto Pass Control CT Noise Figure Meter takes control of the ER Recalls Last Error laauad System Interface Bus CU Selects Upper Frequency of Noise Figure Measurement
57. 70 8SP Display IF Attenuator Settings Display IF SI or 71 0SP Off Off Attenuator IF Attenuator Hold IF Attenuator 72 0 IH or 72 0SP Off Off Off Hold 1Table categories are explained in the Special Functions Detailed Operating Instruction HEE RE RD eK e Z ZZZZZZZZZ ZZZZZZZZZ 2 Section VIL Service ie in the Service Manual The part number of the Service Manual is on the title page of this manual 3 117 Uperation Example Program Codes cz indications Comments Related Sections 3 118 HP 8970B IF Attenuation Selection conta Special Functions 70 71 and 72 To select the IF attenuator hold function LOCAL ammm COGE enema Function ii an aopn i gt program codes For HP IB codes refer to Procedure When Special Function 71 is implemented three digits appear in the left display The digits are either 1 yes or 0 no to indicate whether or not the corresponding attenuator is switched into the 20 MHz IF Assembly circuits see Service Sheets 3 and 4 in Section VIII Service The first most significant digit represents 20 dB The second digit represents 10 dB The third least significant digit represents 5 dB To obtain the IF attenuator setting add the attenuation that is represented by each digit For example a display of 1 0 1 indicates an IF attenuator setting of 25 dB The following table lists the IF attenuation available Special Fu
58. Abort Yes The Noise Figure Meter stops talking and IFC T5 listening TEO Commands Control lines and Interface Functions are defined in IEEE Std 488 1978 Knowledge of these may not be necessary if your controller s manual describes programming in terms of the twelve HP IB Messages shown in the left column Complete HP IB capability as defined in IEEE Std 488 and ANSI Std MC1 1 is SH1 AH1 T5 TEO LA LEO SR1 RL1 PPO DT1 CO and E1 Table 3 4 Functions Not Programmable Via HP IB ee ee Description Control Function Selection Special Function 4 Normal Talker and Listener Talk Only HP IB Addresses Special Function 40 0 Display and Enter Noise Figure Meter Address LINE Switch Turns instrument ON and OFF 3 36 HP 8970B Receiving the Data Message cont d Where more than one code is given for a function either code will serve equally However the mne monic code given is recommended since it is shor ter and more closely represents the function se lected Also the mnemonic code will make deci phering program code strings easier The first codes given are the codes used in all programming examples in this manual The Noise Figure Meter s response to the ASCII character set is as follows a The ASCII characters used for the program codes are the alphabet A through Z the numbers 0 through 9 the period and the minus b Lower case letters are treated the same as upper case le
59. Also the UNCORRECTED NOISE FIGURE LED is illuminated When Special Function 0 0 is executed the SPECIAL FUNCTION key LED turns off if it was on Comments Special Function 0 0 does not affect any data entered by special functions or front panel keys PRESET is identical to the Device Clear command over the HP IB 3 208 Operation HP 8970B HP 8970B Operation Preset Conditions and Power Up Sequence cont d includes Special Functions 0 0 and 0 9 Comments PRESET does not effect calibration data or information in the ENR table cont d Special Function 0 9 PRESET and Special Function 0 0 do not modify any data in the internal storage registers When using HP IB code 0 9SP to issue Special Function 0 9 allow ten seconds to pass before giving the next command Related Calibration Frequency Sections Special Functions 3 209 wperauon Description 3 210 OX ee os HP 89708 Programming The System LO Special Function 42 Special Function 42 can be used to modify the predefined system local oscillator programs for the HP 8340B 8341B Sweep Oscillator Special Function 41 4 HP 8350B Sweep Oscillator Special Function 41 0 the HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 the HP 8673B C Synthesized Signal Generator Special Function 41 3 or a custom local oscillator Special Function 41 5 Special Function 42 can also be used to define a new program for other system local oscillators provid
60. Bus refer to Service 04 SRQ not being set by A14U28 or not being detected Try another HP IB cable by Al4U2 refer to Service System Interface Bus could not serial poll Try another HP IB cable Hewlett Packard Interface Bus refer to Service Collision detect circuit not functioning Try another HP IB cable refer to Service 05 E07 Hewlett Packard Interface Bus could not address Try another HP IB cable E Eg System Interface Bus refer to Service Hewlett Packard Interface Bus could not send a Try another HP IB cable message to the System Interface Bus refer to Service 1 Service is in Section VIII of the Service Manual The part number of the Service Manual is on the title page of this manual 3 32 HP 8970B 3 14 REMOTE OPERATION The Noise Figure Meter can be operated through the Hewlett Packard Interface Bus HP IB Bus compatibility programming and data formats are described in the following paragraphs The Noise Figure Meter can operate in two mutu ally exclusive modes on the HP IB 1 Normal Talker Listener Mode This mode is used when the Noise Figure Meter is under the control of an HP IB compatible computer or controller 2 Talk Only Mode This mode is used to output data to a device that is operating in the Listen Only Mode Most front panel functions special functions and remote only functions are programmable via HP IB Table 3 4 lists the functions that cannot be pro
61. Conducted and Radiated Susceptibility MIL STD 461B 1980 Conducted and radiated suscepti bility meets the requirements of methods CS01 CS02 and RS03 of MIL STD 461B dated 1980 GENERAL Noise Source Drive 28 0 0 1V Noise source ON at up to 60 mA peak Noise source OFF lt 1V Power Requirements Line Voltage 100 120 220 or 240V 5 10 48 to 66 Hz single phase Power Dissipation 150 VA maximum Temperature Operating Storage 0 to 55 C 55 to 75 C IEEE STD 488 1978 Compatibility Code SH1 AH1 T5 TEO L4 LEO SR1 RL1 PPO DC1 DT1 CO and El The Hewlett Packard Interface Bus HP IB is Hewlett Packard s implementation of IEEE Std 488 1978 Digital Interface for Programmable Instrumentation Most functions are remotely programmable Remote Operation HP IB Dimensions Height 146 mm 5 75 in Note For ordering cabinet Width 425 mm 16 8 in accessories the module sizes are Depth 462 mm 18 2 in 5 4H 1 MW module width and 17D Net Weight 15 5 kg 34 Ibs 1 6 HP 8970B General Information Table 1 2 Noise Figure Meter Supplemental Characteristics Supplemental characteristics are intended to provide information useful in applying the instrument by giving typical but non warranted performance parameters All parameters describe performance in automati
62. Description Comments Lights Special Function Key tinuous Memory Can be Stored and Recalled Special Functions 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions System LO Commands Auxiliary Commands CW Prefix and Suffix Settling Time in ms Min Frequency in MHz Programming CW MZ the System LO Max Frequency in MHz lt ZZZZKxK Power level in dBm Power Prefix and Suffix Special Function 41 5 Frequency Prefix and Suffix Special Function 41 5 Z Zz Z ZzZZZ mo d ed eK Z HP IB Data Refer to Remote NOISE FIGURE Only Output Operation Frequency left display Selection INSERTION GAIN Hari ne i NOISE FIGURE nterlace bus Send gain reference and second stage temperature while calibrating Service Request Disable SRQ Capability clears all enabled conditions Enable Data Ready to cause an SRQ Enable Cal Complete to cause an SRQ Enable HP IB Code Error to cause an SRQ Enable SRQ on the System Interface Bus Enable System Interface Bus control active Refer to Remote Operations Hewlett Packard Interface Bus Enable Instrument Error to cause an SRQ Set Status Byte Mask Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Ap
63. Detailed Operating Instruction i Calibrate the Noise Figure Measurement System in Mode 1 9 this is only required for a CORRECTED NOISE FIGURE AND GAIN measurement If a preamplifier is required for the measurement the preamplifier must be used in the calibration j Insert DUT into the measurement system and make a noise figure or noise figure and gain measurement NOTE The following example assumes that the Noise Figure Meter is the controller An external controller can be used to control the Noise Figure Measurement System and the user controlled local oscillator For more information on using an external controller refer to Comments at the end of this instruction To make a swept CORRECTED NOISE FIGURE AND GAIN single sideband meas urement over an IF of 10 to 12 GHz using 100 MHz steps with a fixed user controlled local oscillator frequency of 5 GHz a Press PRESET or send HP IB code PR to establish initial conditions PRESET selects a single sideband measurement Special Function 17 0 for the Noise Figure Test Set NOTE Measurement Mode 1 9 must be activated prior to entering the fre quency parameters to avoid error E35 entered value is out of range b Press 1 9 SPECIAL FUNCTION or send HP IB code E9 to activate Measure ment Mode 1 9 3 185 PN ws ae oS Uperau0on BLE Vet wns Measurement Mode 1 9 contd Special Function 1 9 Example c Set the frequency parameters for both the calibration and
64. Figure Meter is the System Controller Scan Special Function Catalog Lines Line 1 Status Line 2 Status Line 3 Status Line 4 Status Line 5 Status Line 6 Status Line 7 Status Line 8 Status Auto 20 dB 10 dB 0dB 10 dB Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code 3 55 Operation HP 8970B gt Table 3 9 Special Function to HP IB Code 6 of 7 Special Function Display RF Attenuator Settings RF Attenuator Hold Description 20 dB 30 dB Display RF Attenuators RF Attenuators are held in the configuration that exists when Special Function 62 0 is activated Select RF Thru Path Select 10 dB Pad No 1 Select 20 dB Input Amplifier Select 10 dB Pad No 2 Select 10 dB Pad No 3 Enable Coarse Tuning Calibration Select Upper Frequency of Noise Figure Test Set Auto 0dB 5 dB 10 dB 15 dB 20 dB 25 dB 30 dB 35 dB Display IF Attenuators IF Attenuators are held in the configuration that exists when Special Function 72 0 is activated Noise Source Off Noise Source On Enable Recorder Test X Axis Test Y Axis Test Display Key Codes Key Test Row 1 Key Test Row 2 Key Test Row 3 Key Test Row 4 Key Test Row 5 Key Test Row 6 Key Test Row 7 Key Test Row 8 Enable Display Test Individual RF Attenuator Selection Noise Figure Test Set YIG Filter Coars
65. Figure Meter that the plotter is on the System Interface Bus The use of Special Function 47 0 is described in the Data Output to Oscilloscopes Recorders and Plotters Detailed Operating Instruction g Special Function 47 1 conveys to the Noise Figure Meter that the plot data is to be read on the Hewlett Packard Interface Bus HP IB The use of Special Function 47 1 is described in the Data Output to Oscilloscopes Recorders and Plotters Detailed Operat ing Instruction h Special Function 48 0 enables the Noise Figure Meter to be the system controller on the System Interface Bus Error forty eight E48 is generated if another controller has been enabled as controller on the System Interface Bus and Special Function 48 is active l i Special Function 48 1 conveys to the Noise Figure Meter that it is not the system controller on the System Interface Bus This special function is useful if another controller is to share the System Interface Bus with the Noise Figure Meter j Special Function 48 2 disables error forty eight E48 Error forty eight occurs when the Noise Figure Meter has been told that it will be the controller on the System interface Bus Special Function 48 0 and the Noise Figure Meter detects another controller on the System Interface Bus If this special function is to be used ensure that the error condition does not exist Check cabling carefully k Special Function 49 0 disables auto pass control For instruments with
66. Fixed IF or LO Frequency Selection conta Special Functions 3 and 19 The HP IB codes for Hz and MHz are HZ and MZ respectively For Special Functions 3 and 19 program codes refer to Procedure When Special Function 3 0 3 1 or 19 2 through 19 4 is selected the left display shows the current IF or LO frequency When anew frequency value is entered it appearsin the left display only for as long as the ENTER key is depressed When the ENTER key is released the left display returns to the display that was present when the special function was entered When Special Function 19 5 is selected the left display shows the current frequency being input to the Noise Figure Meter The display is cleared by pressing the FREQUENCY key If error code E32 is displayed when attempting to enter a fixed LO frequency the entered frequency is outside the range specified for the LO If the entered frequency was incorrect re enter the correct frequency If the LO frequencies are incorrect they can be changed using either Special Function 42 3 or 42 4 refer to Programming the System LO Detailed Operating Instruction The Hz unit provided for HP IB is for programmer convenience The instrument rounds all HP IB tuned frequency inputs to the nearest MHz Error Messages and Recovery Measurement Modes 1 1 through 1 9 Programming the System LO Special Functions HP 8970B Operation HP IB and System Interface Bus SIB Addresses Description
67. Frequency 42 4 Maximum 18000 MHz 18000 MHz 26500 MHz Frequency 42 5 Output Signal 6 dBm 7 dBm 8 dBm Power Level 42 6 Power Prefix M 77 O 79 D 68 58 RF on Mod Power Suffix 42 7 Frequency Prefix 3 212 HP 8970B Predefined Program Listings cont d Procedure Operation Programming The System LO cont d Special Function 42 External LO Predefined Program Listings cont d HP8340B 8341B System LO Commands 41 4 or HP 8671B B672A HP 8673B C a a Special Function 42 HP root Program 41 2 Program 41 3 Program 41 5 Frequency Suffix b The numbers shown within parentheses are the decimal equivalent of the required ASCII or count character It is this decimal value that is entered into the Noise Figure Meter For example in the first line of the listing for the HP 8671B 8672A program the entry is M 77 The M is the first ASCII character of a valid HP IB program code for the HP 8671B 8672A The 77 is the decimal equivalent of the letter M The two exceptions to this rule are 0 in the HP 8340B 8341B 8350B program and 255 in the HP 8671B 8672A program The 0 entry is used as a placeholder It is ignored by the Noise Figure Meter and is not transmitted on the HP IB In the HP 8340B 8341B 8350B program Special Functions 41 0 and 41 4 there are no preset auxiliary commands This area contains zeros because no single program can control all possible
68. Frequency Calibration Input Gain Selection Measurement Modes 1 0 through 1 9 Noise Figure Uncorrected and Noise Figure and Gain Corrected Sweep Trigger Selection HP 8970B Description Procedure Operation Calibration Frequency Special Function 31 Frequency Calibration is performed to ensure the accuracy of the displayed tuned frequency During frequency calibration the instrument s first local oscillator the YIG oscillator is tuned to the first IF 2050 MHz Since the first mixer is not perfectly balanced some of the first local oscillator power is fed through to the first IF This signal is mixed down to the third IF It is then detected by a special narrow band detector approximately 100 kHz wide The YIG oscillator is then stepped through the narrow band detectors s pass band using a special fine tune digital to analog converter DAC When the peak output is detected the YIG oscillator is tuned to 2050 MHz first IF This IF corresponds to 0 MHz on the front panel frequency display The fine tune DAC is held at this value This correction value is then used when the YIG oscillator is tuned in response to subsequent tuning changes Frequency calibration is initiated by the following a The LINE switch is pressed to apply power to the instrument b The PRESET key is pressed or the CALIBRATE key is pressed if Special Function 31 0 is active c Special Function 31 is used to initiate and control freq
69. HP 8340B 8341B 8350B configurations This portion of the program must be correctly entered by the user to match the configuration of the HP 8340B 8341B 8350B used with the Noise Figure Meter The 255 in the HP 8671B 8672A program is used by the Noise Figure Meter to establish that when controlling the HP 8671B 8672A leading zeros must be sent if they are required to complete five digits of frequency data c The numbers shown without parentheses in Special Functions 42 2 42 3 and 42 4 are the actual values used for that function For example the 60 ms shown as the settling time for the HP 8340B 8341B 8350B program is the actual settling time allowed by that program d The comments following the brackets such as in the HP 8671B 8672A program are the functions performed by each HP IB code Note that many two character HP IB codes use the first character to establish the instrument function and the second character to establish the setting of that function In all the programs a maximum five digits of frequency information are sent between the prefix and the suffix This information is generated by the front panel settings of frequency parameters on the Noise Figure Meter To activate a specific programming function key in the corresponding Special Function code and then press the SPECIAL FUNCTION key 3 213 Operation HP 8970B Procedure oo con t oe 5 lt 6 5 z E E z E e FE Special Function Program Be s z
70. HP IB A description of the Service Request Condition Spe cial Function and the procedure for enabling the various conditions are given in the following paragraphs NOTE Each condition of the Status Byte can be enabled separately or all the conditions can be enabled at once Special Func tion 44 7 Desired conditions of the Extended Status Byte must be enabled allatonce Special Function 44 9 If the enabled conditions of the Status Byte are changed it is a good practice to first disable the SRQ capability and then enter the required enabled conditions A description of the Status Byte and Extended Status Byte bits is found in the HP IB Syntax and Characteristics Summary Operation Enabling the Service Request Condition cont d Table 3 7 Service Request Enabled Conditions Summary Disables the SRQ capability clears all enabled conditions Enable Data Ready Enable Noise Figure Meter Calibration Complete not for Zero Frequency or IF Calibration Enable HP IB Code Error Enable SRQ on the System Interface Bus Enable Noise Figure Meter received control on the System Interface Bus Enable Instrument Error Set entire Status Byte Mask Enable Extended Status Byte Set the Extended Status Byte Mask a Send the HP IB Code QO to clear all the enabled conditions of the Status Byte The enabled conditions of the Extended Status Byte are not cleared with Q0 The Extended Status Byte enabled conditions are clea
71. Modes Test Set EO Mode 1 0 El Mode 1 1 If code C is used the gain accuracy specification will be degraded from 0 15 dB to a typical value of 0 25 dB For more information refer to Calibration IF Attenuators Detailed Operating Instruction 3 47 Operation HP IB Code HP 8970B Table 3 8 Noise Figure Meter HP IB Code to Parameter Summary 2 of 4 Parameter Measurement Modes cont d Mode 1 2 Mode 1 3 Mode 1 4 Mode 1 5 Mode 1 6 Mode 1 7 Mode 1 8 Mode 1 9 START FREQ STOP FREQ Custom LO CW Prefix and Suffix Disable Noise Figure Test Set Fine Tuning Calibration with Noise Figure Measurement System Calibration warning E28 when fine tune needed Noise Figure Test Set Fine Tuning Calibration at the current Frequency FREQ INCR FREQUENCY Noise Figure Test Set Fine Tuning Calibration with Noise Figure Measure ment System Calibration warning E28 when fine tune needed Disable Noise Figure Test Set Fine Tuning Calibration before Noise Figure Measurement System Calibration and disable Error 28 E28 Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Smoothing Factor Gain Lower Limit for Oscilloscope Select Gain Pen Number Gain Upper Limit for Oscilloscope Special Function Catalog Scan Catalog Lines Line 1 Status Line 2 Status Line 3 Status Line 4 Status Line 5 Status Line 6 Sta
72. Noise Figure Meter Noise Figure Test Set and system local oscillator from 18000 to 99999 MHz This mode provides for using a fixed frequency user controlled local oscillator and a variable IF Frequency conver sion is allowed for in the device under test DUT Although the signal measured atthe Noise Figure Measurement System INPUT is always in the range of 10 to 18000 MHz _ the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency However the correct 10 to 18000 MHz ENR is used during calibration A typical DUT is a mixer or receiver All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements Or the measurement results for each mode can be displayed on an oscilloscope or output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction The following minimum requirements are necessary for the Noise Figure Measurement System and the user controlled local oscillator to operate in Measurement Mode 1 9 a Thesystem local oscillator and the Noise Figure Test Set must be connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable
73. Noise Figure Meter and terminate the program after the measurement in which they are equal External filtering is necessary for single sideband measurements using Special Func tions 2 1 through 2 3 Calibrate Controller Capability of the Noise Figure Meter Fixed IF or LO Frequency Selection Measurement Modes Sideband Selection Special Functions Trigger Selection 3 139 Wperavulvil aas wys war Measurement Mode 1 2 Special Function 1 2 Description Measurement Mode 1 2 provides a means of using a fixed frequency system LO with a variable IF in order to measure over a band of frequencies less than 1600 MHz wide This mode allows for frequency conversion in the measurement system but not in the device under test DUT Single sideband operation and external filtering of the un wanted sideband are required A typical DUT is an amplifier with a bandwidth of less than 1600 MHz The system LO an external filter and a mixer are required Although the signal measured at the Noise Figure Meter INPUT is always in the range of 10 to 1600 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIG URE AND GAIN measurements Or the measurement results for each mode can be displayed on an oscilloscope
74. Operation Measurement Mode 1 0 conta Special Function 1 0 Example cont d Function gmmansna Jata mm Function OOO amp LOCAL keystrokes Ea G C5 o amp Re ee E gt i Function pea rogram codes TR Function Code Code Data Function d To calibrate the Noise Figure Meter set up the equipment as shown below HP 89708 NOISE FIGURE METER PREAMPLIFIER F THE PREAMPLIFIER IS NEEDED FOR THE MEASUREMENT iT MUST BE USED DURING THE CALIBRATION e Calibrate the equipment in Measurement Mode 1 0 by pressing CALIBRATE twice or send HP IB code CA The Noise Figure Meter was set to Measurement Mode 1 0 when PRESET was pressed f To make the measurement set up the equipment as shown below HP 89708 NOISE FIGURE METER 0 1600 MHz INPUT DUT g Press CORRECTED NOISE FIGURE AND GAIN or send HP IB code M2 NOISE PREAMPLIFIER SOURCE IF NEEDED h Press SINGLE or send HP IB code W2 The Noise Figure Meter will sweep from 100 MHz to 150 MHz in 1 MHz steps and halt 3 133 Ne pd ELAS Program Codes Indications Comments Related Sections 3 134 44k OVIVED Measurement Mode 1 0 conta Special Function 1 0 The HP IB code for Measurement Mode 1 0 is EOQ or 1 0SP The left display shows each frequency at which a measurement is made The INSERTION GAIN display shows the gain of the DUT at the displayed frequency The NOISE FIG
75. Power Up Sequence Sequence Special Functions Operation Description 3 258 HP 8970B Sweep The Noise Figure Meter Noise Figure Measurement System can sweep the measure ment frequency from START FREQ to STOP FREQ The frequency changes in discrete steps as set by STEP SIZE rather than in a continuous analog manner The allowable sweep range depends on the measurement mode selected 10 to 1600 MHz 1 to 99999 MHz Depends on the frequency range of the system LO and the noise source gt 10 to lt 1600 MHz System LO must be set up so that variable IF sweeps 10 to 1600 MHz 1 to 99999 MHz Depends on the frequency range of the system LO and the noise source 10 to 1600 MHz IF port response of mixer is being measured Left e shows IF 10 to 16000 MHz 1 6 1 to 99999 MHz e on frequency range of user controlled local oscillator and the noise source 1 7 10 to 18000 MHz User controlled local oscillator must be set up so that variable IF sweeps 10 to 18000 MHz 1 8 1 to 99999 MHz Depends on frequency range of user controlled local oscillator and the noise source 1 9 10 to 18000 MHz IF port response of mixer is being measured Left display shows IF i Depending on the Measurement Mode selected the START FREQ STOP FREQ and STEP SIZE default to different values The following table lists the default frequencies for the Measurement Modes HP 8970B Description contd Procedure O
76. Program Codes cz Indications Comments Related Sections Operation Fixed Frequency Tuning contd To tune the instrument to a new frequency of 100 MHz LOCAL Function Fel Data samma Function keystrokes 1 o 0 gt FR100MZ poe l program codes MR Function The HP IB program code for FREQUENCY is FR The program codes for Hz and MHz are HZ and MZ Pressing the FREQUENCY key clears an incomplete entry displays the current tuned frequency and enables the entry of a new tuned frequency As the entry numbers are pressed the specific numbers appear in the left display When ENTER is pressed the instrument is tuned to the specified frequency and the instrument continues to make the the last selected measurement Front panel frequency entries should be made in integer MHz units If a decimal MHz entry is made the instrument rounds the entry to the nearest integer 0 5 MHz and above is rounded up The Hz unit provided for HP IB is for programmer convenience The instrument rounds all HP IB tuned frequency inputs to the nearest MHz If no other prefix key has been pressed any digits entered followed by ENTER will be interpreted as if the FREQUENCY key were the prefix For highest repeatability always tune in the same manner direction and step size as the calibration was done Fixed Frequency Increment Measurement Modes 1 0 through 1 9 Preset Conditions and Power Up Sequence 3 109 Operatio
77. SB Show serial poll retum value 60 Error 0 iClear subroutine error code 70 Wait_poll Wait for the serial poll to finish 80 ENTER 708 V W2 W3 Get Noise Figure Meter frequency window 90 tThe value returned will be 2000 plus 19 unti the 100 poll is completed or it is aborted due to an error 110 such as the device is not present or is off t20 130 IF V22000 THEN GOTO Wait_poll Wait for the serial poll to be complete 140 150 At this point the poll is complete or is in error 160 We find out which is the case in the next statement 170 If the value is 1000 plus 19 there has been an error 180 Ithe device was not found or it was off If the device 190 was present and the serial poll worked the value will 200 be 0 through 255 for the serial poli value i 210 220 IF V21000 THEN lAn error has occurred 230 Eror lindicate error to program 240 END IF 250 260 The subroutine will return V serial poli value 270 land Error 0 if the serial poll is valid or Error lt gt 0 280 lif the serial poll failed 290 300 IF Eror lt gt 0 THEN 310 PRINT SERIAL POLL FAILED 320 ELSE 330 PRINT SERIAL POLL VALUE V 340 END IF 350 END Related Measurement Modes 1 0 through 1 9 Sections 3 270 HP 8970B Description Procedure Operation Temperature Units Selection Special Function 11 Temperature units are used when loss temperature Tho or Teo data is entered into the instrument T
78. SPECIAL FUNCTION This displays the start address of the IF attenuator calibration table baer de i l Addl tothe least significant digit shown in the left display of the Noise Figure Meter and record the value _ 2 3 Address of the first attenuator data in calibration table m Keyin93 0SPECIALFUNCTION This enables you to enter the RAM address of the first attenuator data in the calibration table It also automatically increments the address after pressing ENTER so that you can step through the calibration table j D 7 on Enter the number from step l and press ENTER o Key in 93 4 SPECIAL FUNCTION This enables you to read and or modify the 5 dB attenuator value in RAM B P0 p The number shown in the left display is the 5 dB attenuator value in linear units Key in the new 5 dB attenuator value and press ENTER To leave the value shown in the left display unchanged press ENTER without keying in a new value 4 15 Performance Tests l HP 8970B PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST con d Procedure cont d q Press 93 4SPECIALFUN cher to view the next attenuator value Enter the new value and press ENTER 9 ons r Repeat step q for each subsequent attenuator value until all values have been entered s Press FREQUENCY to return to normal operation NOTE Error code E26 internal IF attenuators not calibrated will occur after E80 continuous memory failure To cl
79. Sequence The Noise Figure Meter per forms a quick internal check at turn on During this check all front panel indicators light for approximately two seconds to allow a quick visual inspection of each front panel display annunciator and display segment If a failure is detected an error code will appear in the NOISE FIGURE display to indicate the nature of the failure For error codes E10 through E49 and E80 refer to Error Messages and Recovery in the Detailed Operating Instructions For error codes E60 through E80 refer to Section VIII Service If the memory check was successful Ctrl will appear in the INSERTION GAIN display and on or OFF will appear in the NOISE FIGURE display If the Noise Figure Meter is the system controller on the System Interface Bus Special Function 48 0 on will be displayed If the Noise Figure Meter is not the system controller on the System Interface Bus Special Function 48 1 OFF will be displayed Then Fr will appearin the INSERTION GAIN display and CAL will appear in the NOISE FIGURE display for approxi mately five seconds while the Noise Figure Meter performs a frequency calibration After the frequency calibration the instrument powers up to the last front panel configuration prior to being turned off Refer to Preset Conditions and Power Up Sequence in the Detailed Operating Instructions for additional information NOTE An internal battery is used
80. Special Function 47 0 plotter is on the System Interface Bus active m The address of the plotter must match the address of the plotter stored in the Noise Figure Meter Use Special Function 40 3 plotter system interface bus address to display and change if necessary the address of the plotter stored in the Noise Figure Meter The default address for the plotter is 5 NOTE When the plot starts Error 45 45 will be given if the Noise Figure Meter can not find the plotter at the address set by Special Function 40 3 the plotter is not turned on or the plotter is not connected to the SYSTEM INTERFACE BUS connecior with an HP IB cable n The default title of the plot will be HP 8970B Noise Figure Meter The user can supply a title using Special Function 25 5 The title is placed at the top of the plot grid and can be sixty five 65 characters long The titleis entered with ASCII characters in decimal using the front panel numeric key pad When using HP IB the titleis sent the way it will appear on the plot For example a title would be sent over HP IB using the following format OUTPUT 708 WT This would be a title of up to 65 characters o The pens used to make the plot can be selected using Special Functions 25 3 noise and 25 4 gain curve The default pens are 1 noise and 2 gain 3 77 VWperalion Wr sv UB Data Output to Oscilloscopes Recorders and Plotters contd Special Functions 7 8 and 20 through
81. Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 1Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 250 HP 8970B Operation Table 3 14 Special Function Summary 13 of 15 gt Szjsg Sess SE 53 pE Es n E Program Sceis Sats ES uE Sollog wS 2 ss References and cm Description ZES2 2c FS Sse ss Gels Ssi es o 4s Fd Comment S5 ez emeim amp ao ammenis mad Lt CUS OO ee OS Ge G9 Mma Test Display Key Codes Key Test Row 1 Key Test Row 2 Key Test Row 3 Key Test Row 4 Key Test Row 5 Key Test Row 6 Key Test Row 7 Key Test Row 8 Refer to Section VIL Service 2inzAwAAAAAA A A Z2i4242AAAAAANAARNAY Y Display Test 91 0 DT Enable Display Test N Off Off Off Refer to Section VIII Service 0 MHz Hold 92 0 U0 N On On 92 1 N Off Off 93 0 Refer to Section VIII Service Sets the address for Refer to Section Tea modification or inspec VIII Service Modification tion and enables auto or ROM increment mode i ea AD Sets the address for N N N INC modification or inspec tion and disables auto increment mode MB Selects modification or N NIN Off inspection of a byte in RAM or inspection of a byte in ROM MW
82. TRACE adjusts the intensity of the gain trace on an oscilloscope relative to the noise figure trace HP 8970B Line Power Module permits operation from 100 120 220 or 240 Vac The number visible in the window indicates nominal line voltage to which the instrument must be connected see Figure 2 1 Center conductor is a chassis connection for safety earth ground Fuse 1 5A 250V Normal Blow for 100 120 Vac 1 0 250V Normal Biow for 220 240 Vac System interface Bus SIB Connector Connects the Noise Figure Meter to the System Interface Bus This is the bus that the Noise Figure Meter uses to control the Noise Figure Test Set System Local Oscillator and a plotter HP IB Connector connects the Noise Figure Meter to the Hewlett Packard Interface Bus for HP IB operation X AXIS 0 to 6V output proportional to the measure ment frequency when driving an analog oscilloscope or X Y recorder This output can be made proportional to noise figure for driving a strip chart recorder Output impedance is 1002 amp Y AXIS 0 to 6V output proportional to noise figure when driving an analog oscilloscope or X Y recorder This output can be made proportional to gain when driving a strip chart recorder Output impedance is 1002 7 AXIS PEN LIFT TTL compatible output When used with an analog oscilloscope the Z AXIS provides a TTL high signal for retrace and cursor blanking When used with a recorder the PEN LIFT pr
83. The calibration points are the START FREQ setting the STOP FREQ setting and the frequency steps determined by the setting of STEP SIZE Refer to the Sweep Detailed Operating Instruction for additional information on these keys During calibration each specified frequency in the selected range is calibrated at three input gain settings as selected by Special Function 32 The default gain settings are 20 10 and 0 dB In Measurement Modes 1 0 through 1 4 the calibration data is automatically interpolated between the calibrated points when it is used for a gain measurement and second stage correction Therefore it is not neces sary to calibrate at every frequency that is to be measured However Hewlett Packard recommends that each measured point should be a calibrated point In Measurement Modes 1 5 through 1 9 the default Special Function 39 0 is set which does not allow interpolation between calibrated points However the calibration data can be inter polated between calibrated points by using Special Function 39 1 If Special Function 39 0 is active and interpolation is attempted in Measurement Modes 1 5 through 1 9 error code E21 Frequency Out of Calibrated Range or not a calibrated point is generated Also if a corrected measurement is attempted at a frequency less than the START FREQ setting or more than the STOP FREQ setting of the calibration run error code E21 is displayed During a calibration the calibration data can be gath
84. Turn the equipment on and allow a twenty 20 minute warm up period before performing the Coarse Tuning Calibration c If the upper frequency limit of the Noise Figure Test Set is to be less than 18000 MHz enter the upper limit using Special Function 64 1 3 193 Operation HP 8970B Noise Figure Test Set YIG Filter Calibration conta Special Functions 36 and 64 Example d After the equipment has warmed up for twenty minutes press 64 0 SPECIAL contd FUNCTION The Coarse Tuning Calibration will take about fifteen 15 minutes NOTE If data is read from the Noise Figure Meter over the Hewlett Packard Interface Bus during a Coarse Tuning Calibration the Noise Figure Meter will output a special HP IB code for the NOISE FIGURE window For more information on this HP IB code refer to the Error Messages and Recovery Detailed Operating Instruction e To view the Coarse Tuning Calibration refer to Viewing a Coarse or Fine Tuning Calibration on an Oscilloscope at the end of the Example section Fine Tuning Calibration The following discussion will describe how to perform a Fine Tuning Calibration NOTE Fine Tuning Calibration is only required when single sideband opera tion Special Function 17 0 has been selected on the Noise Figure Test Set and the measurement frequency is greater than 2400 MHz SSB3 There is no limit on the number of times that a Fine Tuning Calibration may be performed But a Fine Tuning Calibration
85. Y AXIS and Z AXIS outputs from the Noise Figure Meter to the X Y and pen lifts inputs of the X Y recorder Select DC mode on all recorder inputs y To adjust the lower left point on the recorder press 20 0 SPECIAL FUNCTION or send HP IB code LL and adjust the X and Y zero set controls on the recorder z To adjust the upper right point on the recorder press 21 0 SPECIAL FUNCTION or send HP IB code UR and adjust the X and Y vernier controls on the recorder NOTE The X AXIS and Y AXIS output voltages from the Noise Figure Meter vary from 0 to 6V Therefore it may be necessary to adjust the recorder to accommodate this range of voltages aa Check both the upper and lower limits on the recorder and readjust as required ab To plot a single sweep of the noise figure results press 2 2 0 SPECIAL FUNCTION and then SINGLE or send HP IB codes A4W2 When the single sweep is complete the Noise Figure Meter remains tuned to the stop frequency ac To plota single sweep of the gain results press 23 0SPECIAL FUNCTION and then SINGLE or send HP IB codes A5W2 When the single sweep is complete the Noise Figure Meter remains tuned to the stop frequency ad The plotted traces should be similar to the traces that were displayed on the oscilloscope 3 79 Operation HP 8970B Data Output to Oscilloscopes Recorders and Plotters conta Special Functions 7 8 and 20 through 25 Program For HP IB codes refer to Procedure
86. and cannot be stored and recalled refer to Table 3 14 Special Function Summary in the Special Functions Detailed Operating Instruction Preset Conditions and Power Up Sequence Special Functions Store and Recall 3 225 Operation Description 3 226 HP 8970B Sideband Selection Special Functions 2 and 17 Special Functions 2 0 through 2 2 are used when external down conversion is used with the Noise Figure Meter or Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator Special Functions 2 0 through 2 2 convey to the Noise Figure Meter the sideband operation double sideband upper sideband or lower sideband being used with the external down conversion Special Function 2 3 is used when up conversion is employed with the Noise Figure Meter or Noise Figure Measurement System Special Function 2 is used in Measurement Modes 1 1 through 1 4 1 7 and 1 9 Special Function 2 is optional with Measurement Modes 1 6 or 1 8 Since the user controlled local oscillator used in Measurement Modes 1 6 and 1 8 produces a fixed IF and is not controlled by the Noise Figure Measurement System Special Function 2 is optional However if Special Function 3 2 display user controlled local oscillator frequency in Measurement Modes 1 6 through 1 9 is desired Special Function 2 will have to be used In Measurement Modes 1 2 or 1 7 one of the single sideband special functions must be selected or e
87. and m A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the measurement frequency that is read from the Noise Figure Meter with the stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal Calibrate Controller Capability of the Noise Figure Meter Fixed IF or LO Frequency Selection HP IB Addresses Noise Figure Test Set YIG Filter Calibration Sideband Selection Special Functions System Interface Bus Control Trigger Selection HP 8970B Description Requirements Operation Measurement Mode 1 9 Special Function 1 9 NOTE The HP 8971B Noise Figure Test Set a system local oscillator and a user controlled local oscillator are needed for Measurement Mode 1 9 Measurement Mode 1 9 uses two stages of frequency conversion The user controlled local oscillator and the device under test provide the first stage of conversion The user controlled local oscillator is not controlled by the Noise Figure Meter the user controlled local oscillator must be controlled by the user The second stage of conversion is provided by the system local oscillator and the Noise Figure Test Set The Noise Figure Meter does control the system local oscillator and the Noise Figure Test Set Measurement Mode 1 9 provides the means of increasing the frequency range of the Noise Figure Measurement System
88. and output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction Requirements The following minimum requirements are necessary for the Noise Figure Meter to act as a controller in Measurement Mode 1 2 a The system local oscillator is connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 active Noise Figure Meter is controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 46 0 active Enable local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 d The address of the system local oscillator must match the system local oscillator address that is stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator address to display and change this address if necessary The default address is 19 after using Special Function 0 9 e The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below HP 8350B Sweep Oscillator Special Function 41 0 HP 8671B 8672A Synthesized Signal Generators Special Funct
89. and remote operator s checks and operator s maintenance procedures Also pro vided are operation and operator s checks for the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and System Local Oscillator Operation of the Noise Figure Mea surement System is described under Measurement Modes 1 5 through 1 9 3 2 Operating Characteristics Table 3 1 briefly summarizes the major operating characteristics of the Noise Figure Meter This table is not intended to be an in depth listing of all operations and ranges but gives a rough idea of the instrument s capabilities For more informa tion on the Noise Figure Meter s capabilities refer to Table 1 1 Specifications and Table 1 2 Sup plemental Characteristics For information on HP IB capabilities refer to the summary con tained in Table 3 3 Message Reference Table 3 3 Local Operation Information covering front panel operation of the Noise Figure Meter is given in the sections des cribed below To rapidly learn the operation of the instrument begin with Simplified Operation and Operator s Checks Once familiar with the general operation of the instrument use the Detailed Operating Instructions for in depth and complete information in operating the Noise Figure Meter General Operating Information Instructions relat ing to the Noise Figure Meter turn on procedure and various keystroke sequences are presented to acquaint the user with th
90. codes Allow sufficient time for the output of the local oscillator to stabilize i Send the command RM 2EN RS CA Wait for a seria poll to return a non zero value indicating calibration is complete j Insert the DUT into the measurement system k Special Function 30 1 trigger hold must be active HP IB code is T1 l Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 m Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep n Amethod must be determined when to step to a new frequency and read the noise figure results This read operation cannot be completed until the new data is ready Itis possible to write an SRQ interrupt routine on the Data Ready SRQ Refer to Enabling the Service Request Condition paragraph 3 30 o Continue to loop through steps m and n A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the frequency that was read from the Noise Figure Meter with the stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal External filtering is necessary for single sideband measurements using Special Func tions 2 1 through 2 3 Calibrate Controller Capability of the Noise Figure Meter Fixed IF or LO Frequency Se
91. dB 10 0 and 10 dB 0 10 and 20 dB 10 20 and 30 dB Calibrate IF Attenuators Off On Enter Loss before DUT in dB Enter Temperature of Losses Enter Loss after DUT in dB Manual Automatic Set Clear Fine Tuning Calibration with Noise Figure Measurement System Calibration enable Warning E28 if Fine Tuning is needed Disable Fine Tuning Calibration before Noise Figure Measurement System Calibration Disable Fine Tuning Calibration before Noise Figure Measurement System Calibration and Disable Warning E28 if Fine Tuning is needed Fine Tuning Calibration from Start to Stop Frequencies and Disable Fine Tuning Calibration before Noise Figure Measurement System Calibration Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code f Special Function 33 1 is used the gain accuracy specification will be degraded from 0 15 dB to a typical value of 0 25 dB For more information refer to Calibration IF Attenuators Detailed Operating Instruction 3 53 Operation HP 8970B Table 3 9 Special Function to HP IB Code 4 of 7 Special Function Fine Tuning Calibration at Current Frequency Interpolated Measurements Disable Interpolated Measurements in Modes 1 5 through 1 9 Enable Interpolated Measurements in Modes 1 5 through 1 9 HP IB and SIB Addresses Display and Enter Noise Figure Meter Address Display and Enter System LO Address Display and Enter No
92. done in the same direction as the calibration for example from start frequency to stop frequency This example assumes that the user controlled local oscillator is tuned to the specified frequency 5 GHz i Press CORRECTED NOISE FIGURE AND GAIN or send HP IB code M2 j Press SINGLE or send HP IB code W2 The Noise Figure Measurement System will sweep from 10 to 12 GHzin 100 MHz steps After the single sweep is completed the system halts The HP IB code for Measurement Mode 1 9 is E9 or 1 9SP The Comments section contains additional HP IB codes when using an external controller The left display shows each IF frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain ofthe DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used to control the Noise Figure Measurement System and the user controlled local oscillatorin Measurement Mode 1 9 The following general conditions must be observed when using an external controller a The external controller and the user controlled local oscillator must be connected to the HP IB connector on the Noise Figure Meter b HP IB code Hi must be active c Special Function 4 0 normal talker and listener must be active Note that there is no HP IB code for this special function d Special Function 30 0 free run should be active
93. drift in both the measurement equipment and the Noise Figure Meter The more rapidly the test is performed the more closely the test results will indicate the actual performance of the instrument If the instrument fails by a narrow margin performing the test more quickly will proba bly allow the instrument to pass Since the Noise Figure Meter is highly sensitive to RF signals at its input spurious transmissions or noise can adversly affect performance test results Use short well shielded cables and a minimum of adapters when performing this test Attenuator 10 dB 2 required HP 8491A Opt 010 Attenuator 20 dB sssossseesssssresos HP 8491A Opt 020 Attenuator 1 dB Step HP 8494A Opt 001 Attenuator 10 dB Step 2 22 0 ees HP 8495A Opt 001 Filter Low Pass oscsnnitedisec wes iexean HP 360B Noise Source anonorsancrsrsereereres HP 346B Opt 001 Power Meter s440 050s5056080 eisnew ented HP 436A Power Sensor 0csccccccccccrecccces HP 8484A Power Splitter shia sede Osea dawsanseeiea HP 11667A Wideband Amplifier I 0005 HP 8447D Opt 010 Wideband Amplifier II HP 8447F Opt 010 Digital Voltmeter sssssresseeresseo HP 3456A 4 10 HP 8970B Performance Tests PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure IF Attenuator Calibration 1 Connect the noise source to the Noise Figure Meter
94. f a previous display new display where n is the smoothing factor The eguation for arithmetic is n measurements new display 5 7T where n is the smoothing factor The smoothing factor can range from 1 to 512 in factors of two Each time the INCREASE key is pressed the smoothing factor is doubled until the smoothing factor is 512 Each time the DECREASE key is pressed the smoothing factor is halved until the smoothing factor is 1 A stable display can usually be obtained by increasing the smoothing factor When exponential smoothing is used for a fixed frequency measurement the display is updated approximately five times per second for all smoothing factors However when a large smoothing factor is used the Noise Figure Meter is slow to respond to changes in the noise measurement when tuning from one fixed frequency to another Arithmetic smoothing makes the number of measurements indicated by the smoothing factor and averages them before the result is displayed The display is updated each time n measurements are made where n is the smoothing factor With a smoothing factor of 1 sixteen measurement updates are made each second With a smoothing factor of 512 the measurement update interval is typically forty seconds to one minute Calibration and swept measurements always use arithmetic smoothing automatically Either exponential or arithmetic smoothing can be selected for fixed frequency measurements
95. factored out at the fre quency fine tuned by Special Function 36 4 Unless the frequency fine tuned is a calibrated frequency point of the Noise Figure Measurement System e To view the progress of the Fine Tuning Calibration refer to Viewing a Coarse or Fine Tuning Calibration at the end of the Example section Viewing a Coarse or Fine Tuning Calibration on an Oscilloscope The following discus sion will describe how to view a Coarse or Fine Tuning Calibration on an analog oscilloscope NOTE An analog oscilloscope must be used with the Noise Figure Meter A digital oscilloscope won t work with the Noise Figure Meter a Connect the X AXIS Y AXIS and Z AXIS outputs on the rear panel of the Noise Figure Meter to the A B and Z or horizontal vertical and Z inputs of the oscilloscope Select DC mode for all oscilloscope inputs b Press 7 1 SPECIAL FUNCTION or send HP IB code A1 to display the test pattern on the oscilloscope screen c Using the oscilloscope s position and gain controls position the test pattern where desired d Press 97 1 SPECIAL FUNCTION or send HP IB code Y9 The oscilloscope will now display the peaking maximum power at each frequency point for a Coarse or Fine Tuning Calibration when enabled by Special Function 36 or 64 NOTES If a preamplifier is being used the maximum and minimum oscilloscope display limits will need to be changed to view the noise peak at optimum scale Special Functio
96. five digits of the Noise Source serial number are suggested as the number to use as the identifier With Special Function 5 5 activated key in the new identifier The number will begin to appear in the left display press ENTER The values in the other two displays are dependent on what action the Noise Figure Meter is performing and are not affected by the entering of the Noise Source identifier Entering or Editing an ENR tabie NOTES The following procedure describes how to enter a new ENR table The same procedure is used if an existing ENR table is being edited The following discussion describes four keys used to look at data enter data or edit data in an ENR table after the ENR key has been pressed e The UP ARROW and DOWN ARROW allow the user to scroll be tween ENR tables Special Function 5 6 or to scroll through infor mation within a table ENR Editing The DECREASE key is used to delete an ENR entry Press the DECREASE key and the frequency currently being displayed is deleted This key is very helpful in deleting unwanted default frequencies e The INCREASE key is used to insert a new ENR entry before the ENR data currently being displayed After pressing INCREASE the ENR table entry number in the NOISE FIGURE display will be the same number that was displayed before the INCREASE key was pressed The INSERTION GAIN display will show an ENR of 15 2 dB The left display will show a frequency that is the average of th
97. in 200 MHz steps with a fixed IF of 70 MHz NOTE This example assumes that the Noise Figure Meter is acting as a con troller on the System Interface Bus and the minimum requirements specified under Requirements are satisfied Refer to Comments for a brief description of using an external controller when in Measurement Mode 1 1 a Press PRESET to establish initial conditions NOTE Measurement Mode 1 1 must be activated prior to entering the frequency parameters to avoid error E35 entered value is out of range b Press 1 1 SPECIAL FUNCTION to activate Measurement Mode 1 1 c Set the frequency parameters for both the calibration and measurement d Enter actual ENR for the Noise Source if this has not previously been done 3 136 Minaratnn HP Ra7nRr HP 8970B Example cont d Operation Measurement Mode 1 1 contra Special Function 1 1 emia Code sosmamm Function oe sta women FUNCTION eee e ooo AOC MOC o Ze E1IF70MZFAGO000MZFB12000MZSS200MZ Code Eton Code Data Data Code LOCAL keystrokes lt a gt program codes Function Function Code Data Data Code Function e To calibrate the Noise Figure Meter set up the equipment as shown below HP 89708 SYSTEM NOISE FIGURE METER LOCAL OSCILLATOR LO OUTPUT NOISE SOURCE eff THE PREAMPLIFIER iS USED DURING THE MEASUREMENT tT MUST BE USED DURING CALIBRATION f Calibrate the equipment
98. in Measurement Mode 1 1 by pressing CALIBRATE twice g To make the measurement set up the equipment as shown below HP 8970B SYSTEM NOISE FIGURE METER LOCAL OSCILLATOR LO OUTPUT PREAMPLIFIER GF NEEDED 3 137 VIPUL Exampie cont d Program Codes Indications Comments 3 138 Finnen tinn Measurement Mode 1 1 conta Special Function 1 1 h Press CORRECTED NOISE FIGURE AND GAIN i Press SINGLE The Noise Figure Meter will sweep the system LO from 6 GHz to 12 GHz in 200 MHz steps and halt The HP IB code for Measurement Mode 1 1 is El or 1 1SP Refer to Comments for additional information on using HP IB program codes in Measurement Mode 1 1 The left display shows each frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain ofthe DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used in place of the Noise Figure Meter to control the system LO and the Noise Figure Meter in Measurement Mode 1 1 The following general conditions must be observed when using an external controller a Connect the system local oscillator and the external controller to the HP IB connector on the Noise Figure Meter b HP IB code H1 must be active c Special Function 46 1 must be active d Special Function 4 0 normal talker and listener must be active No
99. is not needed each time a measurement is made a Connect the equipment as shown below The noise source should have a minimum ENR Excess Noise Ratio of 13 dB The noise source should be placed as close as possible to the RF INPUT of the Noise Figure Test Set If a preamplifier will be used in the measurement the preamplifier may be placed between the noise source and the RF INPUT during the Fine Tuning Calibration For Measurement Modes 1 6 and 1 7 when there is quite a bit of loss in the measurement setup it is possible to do the Fine Tune Calibration by connecting the noise source directly to the Noise Figure Test Set RF INPUT This will ensure that 13 dB of ENR is available for the Fine Tuning Calibra tion In this case the Fine Tuning Calibration can be performed using Special Function 36 3 In Measurement Modes 1 6 and 1 7 it is also possible to do a Fine Tuning Calibration with the external mixer in place and a preamplifier in the measurement system to increase the available noise power at the Noise Figure Test Set RF INPUT The preamplifier should be low noise or it may affect the Fine Tuning Calibration NOTE Allow the equipment to warm up for twenty 20 minutes before per forming the Fine Tuning Calibration 3 194 HP 8970B Example cont d Operation Noise Figure Test Set YIG Filter Calibration conta Special Functions 36 and 64 SYSTEM LOCAL OSCILLATOR HP 89718 NOISE ae ae IF OUTPUT DRIVE OUTPUT
100. kit contains all the necessary components and full instructions for converting instruments with a front panel INPUT connector to a rear panel connector Order HP part number 08970 60100 1 4 HP 8970B 1 26 MECHANICAL EQUIPMENT AVAILABLE 1 27 Chassis Slide Mount Kit This kitis extremely useful when the Noise Figure Meter is rack mounted Access to internal circuits and components or the rear panel is possible with out removing the instrument from the rack Order HP part number 1494 0060 for 430 mm 17 inch fixed sides and part number 1494 0061 for the correct adapters for non HP rack enclosures 1 28 Chassis Tilt Slide Mount Kit This kit is the same as the Chassis Slide Mount Kit above except that it also allows the tilting of the instrument up or down 90 degrees Order HP part number 1494 0062 for 430 mm 17 inch tilting slides and part number 1494 0061 for the correct adapters for non HP rack enclosures 1 29 RECOMMENDED TEST EQUIPMENT Table 1 5 lists the test equipment recommended for use in testing adjusting and servicing the Noise Figure Meter The Critical Specification column describes the essential requirements for each piece of test equipment Other equipment can be substituted if it meets or exceeds these critical specifications The Recommended Model column may suggest more than one model The first model shown is usually the least expensive single purpose model Alternate models are suggested f
101. listed in the table below The tests are performed as listed in the table The first failure will abort the test If an error is not encountered the HP IB and the SIB are operating properly It is safe to assume that the Noise Figure Test Set is the instrument that is causing the Noise Figure Measurement System problem Refer to the Noise Figure Test Set service manual for troubleshooting assistance Remove the cable connecting the HP IB and SIB connectors Turn the Noise Figure Meter off and then back to on Press 45 1 SPECIAL FUNCTION and 46 0 SPECIAL FUNCTION mmc aero Ah ef AAA 1S SA SSSA Yr SSS SSS SSH ES STH 3 31 Operation HP 8970B OPERATOR S CHECKS Noise Figure Measurement System Check cont d Pao eww OSS Procedure cont d E75 A14U28 the interface hardware or the traces to Try another HP IB cable A14U28 are bad refer to Service E74 Al14U2 or the interface hardware to Al4U2 is bad Try another HP IB cable The interface hardware to A14U28 is good refer to Service May be caused by the following REN or ATN line has failed REN and or ATN line drivers are bad or cable connecting the HP IB and SIB connectors is defective E02 Data path has been broken E03 E Try another HP IB cable refer to Service Try another HP IB cable refer to Service System Interface Bus could not send a message to Try another HP IB cable the Hewlett Packard Interface
102. needed if a mixer is being used out in front of the Noise Figure Measurement System and a preamplifier is not being used An Excess Noise Ratio ENR of 13 dB or greater is needed at the input to the Noise Figure Test Set during the fine tuning calibration h Calibrate and fine tune the equipment in Measurement Mode 1 7 by pressing CALIBRATE twice or sending HP IB code CA i To make the measurement set up the equipment as shown below SYSTEM LOCAL OSCILLATOR IF INPUT INPUT GUTPUT HP NOISE FIGURE METER l iF ee OUTPUT Lo K ogres gee oB LS gcooo B20 Deo MIXER Tor NOISE SOURCE INPUT DRIVE OUTPUT PREAMPLIFIER DUT if NEEDED FILTER gt eo NOISE G eTHE FILTER IS NEEDED IF A SINGLE SIDEBAND MEASUREMENT IS BEING MADE NOTE For the Noise Figure Measurement System specifications to be valid the measurement must use the same START FREQ STOP FREQ and STEP SIZE that was used for calibration None of the calibrated points can be skipped Also the measurement must be done in the same direction as the calibration for example from start frequency to stop frequency This example assumes that the user controlled local oscillator is tuned to the specified frequency of 35 GHz j Press CORRECTED NOISE FIGURE AND GAIN or send HP IB code M2 k Press SINGLE or send HP IB code W2 The Noise Figure Measurement System will sweep from 15000 to 5000 MHz in 200 MHz steps but will display the microwave mea
103. number of times at each frequency point This is part of the calibration process If data is read from the Noise Figure Meter over the Hewlett Packard Interface Bus during a Fine Tuning Calibration the Noise Figure Meter will output a special HP IB code forthe NOISE FIGURE window For more information about this HP IB code refer to the Error Mes sages and Recovery Detailed Operating Instruction 3 195 Operation HP 8970B Noise Figure Test Set YIG Filter Calibration contd Special Functions 36 and 64 Example Measurement accuracy is dependent on the temperature inside the cont d Noise Figure Test Set If the temperature drifts approximately five degrees centigrade since the last Fine Tuning Calibration error twenty eight E28 will be generated The Fine Tuning Calibration must be repeated using Special Function 36 3 d If a frequency not selected by START FREQ STOP FREQ or STEP SIZE is desired use Special Function 36 4 To select this frequency press the FREQUENCY key and key in the frequency desired Press ENTER Then press 36 4 SPECIAL FUNCTION to start the Fine Tuning Calibration at the selected frequency NOTE The passbands of the Noise Figure Meter and Noise Figure Test Set are aligned for the frequency fine tuned with Special Function 36 4 When the Noise Figure Measurement System is calibrated fora CORRECTED NOISE FIGURE AND GAIN measurement the noise contributed by the Noise Figure Measurement System is not
104. of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction The following minimum requirements are necessary for the Noise Figure Meter to act as a controller in Measurement Mode 1 4 a The system local oscillator must be connected to the Noise Figure Meter s SYS TEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 active Noise Figure Meter is controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 46 0 active Enable local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 d The address of the system local oscillator must match the system local oscillator address that is stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator address to display and change this address if necessary The default address is 19 after using Specia Function 0 9 e The correct system loca oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below o HP 8350B Sweep Oscillator Special Function 41 0 HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 HP 8673B C Synthesized Signal Generator Special Function 41 3
105. operation and a 1 0A for 220 240 Vac operation are supplied One fuse is factory installed accord ing to the voltage available in the country of original destination Refer to paragraph Line Voltage and Fuse Selection in Section II of this manual 1 20 EQUIPMENT REQUIRED BUT NOT SUPPLIED A noise source such as HP Model 346B 346A or 346C must be used with the Noise Figure Meter The Noise Figure Meter supplies 28 0V pulses to drive the noise source on and off 1 3 General Information 1 21 ELECTRICAL EQUIPMENT AVAILABLE 1 22 HP IB Controllers 4 The Noise Figure Meter has an HP IB interface and can be used with any HP IB compatible computing controller or computer for automatic systems applications 4 23 External Mixers and System Local Oscillators The System Local Oscillator and a balanced mixer are used to extend the frequency range of the Noise Figure Meter The System Local Oscillator is part of the Noise Figure Measurement System Suitable local oscillators include the HP 8671B HP 8672A or HP 8673B standard Synthesized Signal Gener ators and the HP 8340B or HP 8350B Sweep Oscil lators A suitable mixer is the HP HMXR 5001 This mixer is usable over a range of 2 to 12 4 GHz 1 24 Waveguide Coax Adapters The HP 346B C Noise Source combined with the HP X281C or P281C Waveguide Coax Adapter makes avery accurate calibrated waveguide noise source 1 25 Front to Rear Panel Connector Retrofit Kit This
106. oscillator frequency for a decreasing IF sweep Examples of both a fixed IF and a variable local oscillator and a variable IF and fixed local oscillator are shown in the Noise Figure Meter Measurement Passband figure The Noise Figure Meter s input frequency range is 10 to 1600 MHz In Measurement Mode 1 0 a swept measurement can sweep the Noise Figure Meter s 4 MHz passband over the 10 to 1600 MHz range The Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator has a frequency range of 10 to 18000 MHz In Measurement Mode 1 5 a swept measurement can sweep the Noise Figure Measurement System s 4 MHz passband over the 10 to 18000 MHz range In Modes 1 1 1 3 1 6 and 1 8 the IF is fixed and the local oscillator frequency is swept within the frequency ranges previously explained In Modes 1 2 1 4 1 7 and 1 9 the local oscillator frequency is fixed and the IF is swept across the 10 to 1600 MHz 10 to 18000 MHz range In Modes 1 1 1 3 1 4 1 6 1 8 and 1 9 either upper lower sum or both sidebands can be accepted by the Noise Figure Meter Noise Figure Measurement System However in Modes 1 2 and 1 7 a double sideband measurement cannot be made the Noise Figure Meter will display error E34 In these modes a double sideband measurement does not make sense since the IF sweeps and the sidebands get further and further apart Suppose the IF is at 1000 MHz in this condition the average between
107. programmed into the external controller One method is to compare the frequency that is sent to the system LO with the stop frequency programmed into the Noise Figure Meter and terminate the program after the third measurement in which they are equal It is also possible to write an SRQ interrupt routine on the Calibration Complete SRQ Refer to Enabling the Service Request Condition paragraph 3 30 m Insert the DUT into the measurement system n Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 o Set the system LO to the appropriate frequency Refer to the LO s operating manual for the required HP IB codes Allow sufficient time for the output of the LO to stabilize p Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep q Amethod must be determined when to step to a new frequency and read the noise figure results This read operation cannot be completed until the new data is ready Itis possible to write an SRQ interrupt routine on the Data Ready SRQ Refer to Enabling the Service Request Condition paragraph 3 30 r Continue to loop through steps o p and q A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the frequency that was read from the Noise Figure Meter with the stop frequency programmed into the
108. return to the normal display press 15 0 SPECIAL FUNCTI ON and then press UNCORRECTED NOISE FIGURE For HP IB codes refer to Procedure above When Special Functions 15 0 and any 14 N are selected no unit annunciators are lit in the NOISE FIGURE display The number displayed is the power into the detector in mW When Special Function 15 1 is selected UNCORRECTED NOISE FIGURE COR RECTED NOISE FIGURE AND GAIN or any noise figure display unit Special Function 10 can be selected Another way to ensure that stable readings are stored in the Noise Figure Meter s memory during Manual Measurements is to use the Trigger Hold Special Function 30 1 and Trigger Execute Special Function 30 2 In this type of operation only one measurement is taken and stored Therefore it is not critical if the equipment is disconnected prior to switching Manual Measurement Special Functions IF Attenuation Selection RF Attenuation Selection Special Functions Trigger Selection 3 123 3 124 HP 8970B Operation Measurement Modes Special Function 1 Description The Noise Figure Meter has ten Measurement Modes available Each Measurement Mode 1 0 through 1 9 is described individually in a separate Detailed Operating Instruction This discussion covers the capabilities and differences of the individual modes The following table lists the modes and shows their status in different instrument operations DO wo 3 3 g 5 82 Ez Z E
109. set to 3450 MHz Error code E28 will be displayed on the Noise Figure Meter This error can be ignored Press 17 1 SPECIAL FUNCTION Verify that the DSB annunciator on the Noise Figure Test Set is on the LO is set to 3000 MHz and E28 is gone Press 17 0 SPECIAL FUNCTION and 36 2 SPECIAL FUNCTION Verify that error code E28 is still gone Press 36 0 SPECIAL FUNCTION If steps 4 through 9 performed as indicated go to step 12 If there seems to be a problem go to step 11 If any one of the steps 4 through 9 did not perform as indicated check the cabling between the instruments Then repeat steps 4 through 9 Ifthe problem still exists go to step 17 NOTE The following steps will verify if the Noise Figure Measurement System is operating properly If steps 12 through 16 do not perform as indicated go to step 17 On the Noise Figure Meter change the start frequency to 1000 the stop frequency to 5000 and the step size to 1000 The procedure is to press the appropriate key START FREQ STOP FREQ or STEP SIZE key in the new value and press ENTER NOTE Step 13 should not be performed until the Noise Figure Measurement System has had a twenty minute warm up period Twenty minutes is needed for the Noise Figure Measurement System to reach operating temperature On the Noise Figure Meter press CALIBRATE twice CALIBRATE is pressed twice to ensure that a calibration is performed only when desired After CALI BRATE is press
110. should be noted however that only the hold capability Special Function 62 0 is normally used by most operators The hold is required during manual measurements refer to the Manual Measurements Detailed Operating Instruction for additional information The selection and display of specific RF attenuation settings are more likely to be used during adjustment procedures performance tests or troubleshooting procedures In some specialized applications these capabilities can be helpful but care must be exercised when using them It is possible to introduce some very subtle errors in the measurements that the Noise Figure Meter may not be able to guard against Additional information on how to use and interpret these Special Functions is contained in Section VIII Service Procedure To select a specific RF attenuation setting display or hold key in the corresponding 3 222 Special Function code and then press the SPECIAL FUNCTION key Special Function Program Cade Description Code i gt RF Attenuation Selection Lights Special Function Key tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Stored in Con RO or 60 0SP Ri or 60 1SP R2 or 60 2SP R3 or 60 3SP R4 or 60 4SP R5 or 60 5SP R6 or 60 6SP N N N N N N N N N N N N N N Display RF Attenuator Settings Donnien oo seose w o o ow or or RF Attenuato
111. step to a new frequency after reading the noise figure results This read operation cannot be completed until the new data is ready It is possible to write an SRQ interrupt routine on the Data Ready Status Bit Refer to Enabling the Service Request Condition paragraph 3 30 n Continue to loop through steps 1 and m A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the measurement frequency that is read from the Noise Figure Meter with the stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal Calibrate Controller Capability of the Noise Figure Meter ENR Table Entry Fixed IF or LO Frequency Selection Noise Figure Test Set YIG Filter Calibration Sideband Selection Special Functions System Interface Bus Control 3 189 WPeravuiui Description 3 190 Daw nun bo mon LE Us tras Noise Figure Test Set YIG Filter Calibration Special Functions 36 and 64 When the Noise Figure Meter Noise Figure Test Set and system local oscillator are configured to form the Noise Figure Measurement System the passbands of the Noise Figure Meter and the Noise Figure Test Set must be aligned The alignment process involves a Coarse Tuning Calibration Special Function 64 and a Fine Tuning Calibration Special Function 36 Coarse Tuning Calibration Special Function 64 The Coarse Tunin
112. stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal External filtering is necessary for single sideband measurements using Special Func tions 2 1 through 2 3 Related Calibrate Sections Controller Capability of the Noise Figure Meter Fixed IF or LO Frequency Selection HP IB and System Interface Bus SIB Addresses Sideband Selection Special Functions Trigger Selection 3 149 Uperation Description Requirements 3 150 HP 8970B Measurement Mode 1 4 Special Function 1 4 Measurement Mode 1 4 provides a means of using a fixed frequency system LO and testing over a variable IF range This mode allows for frequency conversion in the device under test DUT Although the signal measured at the Noise Figure Meter INPUT is always in the range of 10 to 1600 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency However the correct 10 to 1600 MHz ENR is used during calibration A typical DUT is a mixer or receiver The system LO is required All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements Or the measurement results for each mode can be dis played on an oscilloscope or output to a recorder or plotter For an explanation and comparison
113. sweep is terminated by press ing the AUTO key a second time STEP SIZE Key Causes the programmed frequency step size of the sweep to appear in the left display while the key is depressed Also see Frequency Function Keys STOP FREQ Key Tunes the Noise Figure Meter to the programmed stop frequency and causes that frequency to appear in the left display Aiso see Frequency Function Keys O START FREQ Key Tunes the Noise Figure Meter to the programmed start frequency and causes that frequency to appear in the teft display Also see Frequency Function Keys Figure 3 5 SWEEP and FIXED FREQ Features 3 11 Operation DATA Keys Enter data or Special Function codes Entries are completed by the ENTER key or the SPE CIAL FUNCTION key except for STORE and RECALL 2 ENTER Key Completes keyboard entries other than Special Function codes SPECIAL FUNCTION Key Completes the keyboard entry of a Special Function code Special Functions are instrument operations in addition to those accessible from dedicated front panel keys Refer to Special Functions in the Detailed Operating Instruc tions for a complete listing of user special functions STORE and RECALL Keys Store and recall up to ten 3 12 instrument configurations in storage registers 0 through 9 Front panel features that cannot be stored and later recalled are CALIBRATE SMOOTH ING AUTO or SINGLE SWEEP UNCORRECTED NOISE FIGURE and CORR
114. that will set the frequency or output power Use Special Function 42 to define a new program for other system local oscillators h Ifa free running non synthesized source is being used as the system local oscil lator a Noise Figure Test Set Coarse Tuning Calibration should have been done when the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator was put together The coarse tuning is ONLY required when a free running source is the system loca oscillator or repairs have been made to the Noise Figure Test Set For more information on the coarse tuning refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement un certainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selec tion Detailed Operating Instruction a Verify that the minimum requirements specified under Requirements are satisfied b Press PRESET c Press 1 5 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 5 d Set fr
115. the 7 least significant HP IB data lines to be placed in both their true and false states This check assumes the Noise Figure Meter is able to handshake recognize its own address and properly make the remote local transitions Before beginning this check press the Noise Figure Meter s PRESET key Then press 4 0 SPECIAL FUNCTION HP B5B HP 9000 Series 200 300 Description BASIC BASIC Send the first part of the Remote message REMOTE 7 REMOTE 7 enabling the Noise Figure Meter to remote Address the Noise Figure Meter to listen OUTPUT 708 OUTPUT 708 completing the Remote message then FRI5MZ FRI5MZ send a Data message 3 23 Operation HP 8970B a gt OPERATOR S CHECKS HP IB Functional Checks cont d Receiving the Data Message cont d Operator s Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators are on Response and that the left display shows 15 MHz Local Lockout and Clear Lockout Set Local Messages Note This check determines if the Noise Figure Meter properly receives the Local Lockout message disabling the LOCAL key The check also determines if the Clear Lock out Set Local message is properly received and executed by the Noise Figure Meter This check assumes that the Noise Figure Meter is able to handshake recognize its own address and properly make the remote local transitions Before beginning this check press the Noise Figure Meter s LINE switch OFF th
116. the CALIBRATE key twice PRESET enabled a fine tune Special Function 36 0 to be done each time a calibration is done 3 180 HP 8970B Example cont d Program Codes gt c9 Indications Comments Operation Measurement Mode 1 8 cont d Special Function 1 8 i To make the measurement set up the equipment as shown below SYSTEM LOCAL OSCILLATOR NOISE SOURCE DRIVE OUTPUT FILTER NOISE SOURCE sif A SINGLE SIDEGSAND MEASUREMENT iS BEING MADE A FILTER MUST BE USED NOTE For the Noise Figure Measurement System specifications to be valid the measurement must use the same START FREQ STOP FREQ and STEP SIZE that was used for calibration None of the calibrated points can be skipped Also the measurement must be done in the same direction as the calibration for example from start frequency to stop frequency j Press CORRECTED NOISE FIGURE AND GAIN k Whilein trigger hold mode Special Function 30 1 press SWEEP SINGLE Sweep the user controlled local oscillator from 34000 MHz to 49000 MHz in 200 MHz steps and trigger a measurement at each frequency of interest The HP IB code for Measurement Mode 1 8 is E8 or 1 8SP Refer to Comments for additional information on using HP IB program codes in Measurement Mode 1 8 The left display shows each frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain of the DUT at the displayed frequen
117. the Noise Figure Meter s REMOTE annunciator is now off but that its LISTEN annunciator remains on Sending the Data Message Note This check determines if the Noise Figure Meter properly issues Data messages when addressed to talk This check assumes that the Noise Figure Meter is able to handshake and recognize its own address Before beginning this check press the Noise Figure Meter s LINE switch twice OFF then ON Then after the power up sequence is completed press CORRECTED NOISE FIGURE AND GAIN and 4 0 SPECIAL FUNCTION If an HP 9000 Series 200 300 controller is used a short program is required to perform this check HP 858 HP 9000 Series 200 300 Address the Noise Figure Meter to talk and ENTER 708 V 16V 0 store its output in variable V The output 20 ENTER 708 V is E20 since the Noise Figure Meter is not 30 DISP V calibrated 40 END _ Display the value of V DISP V DISP V Operator s Check that the Noise Figure Meter s REMOTE annunciator is off but that its TALK Response annunciator is on The controller s display should read 90020000000 HP 85B or 9 002E 10 HP 9000 Series 200 300 The 90020 portion of the display corresponds to the data output for the error code E20 not calibrated shown in the Noise Figure Meter s NOISE FIGURE display Receiving the Data Message Note This check determines if the Noise Figure Meter properly receives Data messages The Data messages sent cause
118. timeout is used it should be at least sixty seconds This is necessary because it may take the Noise Figure Meter many seconds to set up the special code for output This is the case for coarse and fine tune calibration 3 22 Receiving the Clear Message The Noise Figure Meter responds to the Clear mes sage by assuming the settings detailed in Table 3 6 The Noise Figure Meter responds equally to the Selected Device Clear SDC bus command when addressed to listen and the Device Clear DCL bus command whether addressed or not The Clear message clears any pending Require Service mes HP 8970B Operation Table 3 6 Response to a Clear Message or Pressing PRESET 1 of 2 e START FREQ STOP FREQ STEP SIZE SWEEP FREQUENCY FREQ INCR SMOOTHING CALIBRATE MEASUREMENT SPECIAL FUNCTION IF Special Function 3 0 LO Frequency Special Function 3 1 Smoothing Factor Special Function 13 2 Spot ENR Special Function 5 3 Thot Special Function 5 4 Teotd Special Function 6 Oscilloscope Limits Special Function 8 Noise Figure Lower Limit Noise Figure Upper Limit Gain Lower Limit Gain Upper Limit System LO Sideband Crossover frequency Measurement Modes 1 5 through 1 9 Special Function 17 2 10 MHz 1600 MHz 20 MHz Off 30 MHz 20 MHz 1 Off UNCORRECTED NOISE FIGURE NOTE Most Special Functions are set to their zero suffix state for exam ple Measurement Mode Selection is set to 1 0 Some are t
119. to a typical value of 0 25 dB If error code E26 IF calibration needed is valid the following methods can be used to calibrate the IF attenuators while maintaining a gain instrumentation uncertainty specification of 0 15 dB If the Noise Figure Meter is due for its annual calibration refer to Section IV Performance Tests Before starting the tests use Special Function 33 1 with an HP 346 B C Noise Source to clear error E26 OR send the Noise Figure Meter to the nearest Hewlett Packard service center for calibration e Ifthe Noise Figure Meter is not due for its annual calibration enter the IF attenuator calibration data that shouid have been recorded in Section IV Table 4 1 at the time of installation see Section IJ Enter the data using the Entering IF Attenuator Values section of the Gain Measurement Uncertainty Performance Test in Section IV This method maintains the gain instrumentation uncertainty specification of 0 15 dB If the Noise Figure Meter is not due for its annual calibration call the local Hewlett Packard service center for the IF attenuator cali bration data The data can then be entered into the Noise Figure Meter The data is entered using the procedure in Section IV the Entering IF Attenuator Values section of the Gain Measurement Uncertainty Performance Test This method maintains the gain instrumentation uncertainty specification of 0 15 dB Perform the IF Attenuator Calib
120. to retain data in continuous memory when the Noise Figure Meter is turned off At turn on the Noise Figure Meter restores the same front panel configuration that was present when last powered down Nine storage registers the ENR tables and other information are also restored 3 9 Keystroke Sequences The Noise Figure Meter s functions can be selected in any order However each function selection Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual Operation requires a prescribed sequence of keystrokes A keystroke sequence can be either a single keystroke or several keystrokes that must be entered in a specific order Functions requiring only single key stroke are PRESET LOCAL UNCORRECTED NOISE FIGURE CORRECTED NOISE FIGURE AND GAIN INCREASE DECREASE AUTO SINGLE lt and The CALIBRATE func tion requires that the calibrate key be pressed twice Frequency parameters are entered in a Function Data ENTER format Data entered following a function will be interpreted for that function only if terminated with the ENTER key Data previ ously entered remains unaffected until the new data entry is terminated by pressing the ENTER key If another function key is pressed before the data entry is terminated that entry will be rejected and the last valid data for the function will remain active The STORE and RECALL functions are use
121. to the Preamplifier Selec tion Detailed Operating Instruction a Verify that the minimum requirements specified under Requirements are satisfied b Press PRESET c Press 1 8 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 8 d Set frequency parameters including the fixed IF Special Function 3 0 e Enter the ENR table for calibration Special Function 5 7 and the ENR table for the measurement Special Function 5 8 Refer to the ENR Table Entry Detailed Oper ating Instruction for more information f Select appropriate smoothing Special Function 13 g Select sideband operation desired Special Function 2 and 17 h Perform a Noise Figure Test Set Fine Tuning Calibration Refer to the Noise Figure Test Set YIG Calibration Detailed Operating Instruction for more information i With the device under test DUT removed perform a calibration of the Noise Figure Measurement System in Mode 1 8 this is only required for a CORRECTED NOISE FIGURE AND GAIN measurement If a preamplifier is required for the measurement the preamplifier must be used in the calibration j Insert DUT and measure the noise figure or noise figure and gain of the DUT Example To make a swept CORRECTED NOISE FIGURE AND GAIN single sideband meas urement in the 30 to 45 GHz range in 200 MHz steps with a fixed IF of 4000 MHz NOTE This example assumes that the Noise Figure Meter ts acting as a con troller and the minimum require
122. to the required frequencies because after the LO tunes to the requested frequency it will be reset to its original frequency Example 1 Modifying the Output Power Level for a Predefined Program In example 1 the HP 8671B 8672A program is modified for different output power levels Modifying the output power level will probably be the most frequent change made to this predefined program NOTE The actual power level command is not contained in the predefined program The power level is entered with a separate Special Function a On the Noise Figure Meter press 41 2 SPECIAL FUNCTION to load the HP 8671B 8672A program from permanent memory to temporary memory b Changing the output power level is a simple procedure Press 42 5 SPECIAL UNCTION and key in the level desired 0 to 30 dBm Press ENTER Be sure not to exceed the limits of the system LO being used For a power level less than 0 dBm or greater than 30 dBm the auxiliary commands can be used c Each time the power level is changed step b is repeated Example 2 Using the Custom Local Oscillator Program The Custom Local Oscillator Special Function 41 5 Program is meant to be used with local oscillators that require anywhere from two 2 to twenty two 22 ASCII characters to define the command sequence that sets the output frequency or output power Special Functions 42 0 Auxiliary Commands 42 2 Settling Time 42 3 Minimum Frequency 42 4 Maximum Frequency and 42 5
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124. 0 01 010 101 01 010 116 01 010 111 0t 011 000 04 011 001 01011010 01 0110114 01011 100 01 011 101 01011 110 Ot O13 411 61 4100 000 01 100 001 01 100 010 01 100 011 0t 100 100 01 400 104 01 100 110 01 100 111 01 101 000 01 101 001 01 101 010 07 101 014 07 104 100 01 104 101 01 101 110 01 101 111 01 140 000 04 148 001 01 110 010 01 110011 01 440 100 01 110 101 01110 140 01110 H1 01 t11 000 01i 111 001 01 141 010 01 141041 04 411 100 Gt 111101 04 114 110 G1 411 111 geca pan esr wF Owa OTM gt 7 NK S VDOT OZZr zuet onmo Nw A HP 8970B Description Procedure Operation Calibrate Includes Special Function 39 Special Functions 39 0 and 39 1 are ONLY used with Measurement Modes 1 5 through 1 9 Special Function 39 0 does not allow interpolated measurements between cali brated points Special Function 39 1 does allow interpolated measurements between calibrated points Pressing the CALIBRATE key initiates a calibration of the instrument and any equipment that is currently connected to the INPUT First a frequency calibration is performed and then the noise figure is measured at each selected calibration point The calibration data obtained is used to measure gain and to perform the second stage correction computations needed to make a CORRECTED NOISE FIGURE AND GAIN measurement
125. 0 Besceiptien BASIC BASIC Send the first part of the Remote message REMOTE 7 REMOTE 7 enabling the Noise Figure Meter to remote Address the Noise Figure Meter to listen OUTPUT 708 OUTPUT 708 completing the Remote message then M2 M2 send a Data message that selects the CORRECTED NOISE FIGURE AND GAIN measurement Operator s Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators are on Response and that the CORRECTED NOISE FIGURE AND GAIN key light is on Send the Clear message setting the Noise CLEAR 708 CLEAR 708 Figure Meter s measurement to UNCOR RECTED NOISE FIGURE Operator s Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators areon Response and that the UNCORRECTED NOISE FIGURE key light is on Abort Message Note This check determines if the Noise Figure Meter becomes unaddressed when it receives the Abort message Before beginning this check enter LOCAL 708 and press the Noise Figure Meter s PRESET key Then press 4 0 SPECIAL FUNCTION HP 85B HP 9000 Series 200 300 Description BASIC BASIC Send the Remote message to the Noise REMOTE 708 REMOTE 708 Figure Meter Operator s Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators are on Response Send the Abort message unaddressing the ABORTIO 7 ABORT 7 Noise Figure Meter from listening Operator s Check that the Noise Figure Meter s LISTEN annunciator is of
126. 0 The difference should be less than 0 03 dB dB Set the signal generator frequency to 2300 MHz Repeat steps 4 through 7 but adjust the signal generator output to give a reading of 25 dBm on the power meter Note the noise figure reading with the signal generator power off dB Note the noise figure reading with the signal generator power on dB Subtract step 26 from step 25 The difference should be less than 0 03 dB dB 4 21 Performance Tests HP 8970B PERFORMANCE TESTS 4 11 JITTER PERFORMANCE TEST Specification Description Equipment Procedure 4 22 JITTER Peak to peak Y factor variation lt 0 15 dB with minimum smoothing peak to peak Y factor variation lt 0 02 dB with increased smoothing for smoothing set to 64 Peak to peak is defined as five times the standard deviation of a statistically valid set of readings Five standard deviations about the mean includes 99 of the readings for a Gaussian distribution The Noise Figure Meter is set to read Y factor in dB A large number of noise figure readings are taken with the noise source connected directly to the Noise Figure Meter s INPUT connector Measurement hold and trigger are used to allow data to be recorded manually Data is then examined to determine compliance with the specification NOTES This procedure is very time consuming If you have an HP 9826 36 controller you can use the program listed at the end of this procedur
127. 0005 3 140 Measurement Mode 1 3 0c00ceee 3 145 Measurement Mode 1 4 baaa 3 150 Measurement Mode 1 5 0 000 3 155 Measurement Mode 1 6 4 3 160 Measurement Mode 1 7 0000005 3 168 Measurement Mode 1 8 00005 3 176 Measurement Mode 1 9 4 3 183 Noise Figure Test Set YIG Filter Calibration ig csvedioxdedewidckwlnedeasds s 8 190 Power Measurements cecceees 3 200 Preset Conditions and Power Up Sequence sesssospenisrenererresresss 3 205 HP 8970B Operation Table 3 2 Detailed Operating Instructions Table of Contents Functional 2 of 2 Section Section Special Functions cont d Special Functions cont d Programming the System LO Spot ENR Thot Teoid and ENR Table Programs Available to Control the Selection System Interface Bus Control RF Attenuation Selection Temperature Units Selection Seguente scriere orense eniai Sa Trigger Selection Sideband Selection Tuning Smoothing Averaging Fixed Frequency Increment Special Function Catalog Fixed Frequency Tuning Special Functions 3 7 Operation 3 8 LOCAL Key Returns the Noise Figure Meter to local operation front panel control from remote HP IB control provided that the instrument is not in Local Lockout P IB Annunciators Display the HP IB status The REMOTE annunciator lights when the Noise Figure Meter is in the remote mode The TALK an
128. 02 VIII Service Functions Reset Noise Figure Test Refer to Section Set YIG Filter Heater VII Service Most Specia Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 1 Section VII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 252 HP 8970B Operation Table 3 14 Special Function Summary 15 of 15 a zo S ia8 ws lu s e SESE ES ES Se 25 Special Function Sc sBsE4 S SS tS tf g ps ca Cd Descrioti 22g S sE nS go SS References and scription 3 23 2T sco BE ss t swivel bade C D SS i Ret e FO aa a we moe Enable HP IB and SIB test Refer to Section VHI Service Packard Interface Bus and System Interface Bus Test Noise Figure Meter RAM Test Noise Figure Test Set Self Test Enable RAM test Refer to Section VII Service Enable Noise Figure Test Set Self Test Refer to Section VIII Service Last Error 99 1 ER Recall last error issued Ni N N Of Off Off Refer to Section VIII Service Noise Figure 99 7 Display Noise Figure N IN N Off Off Off Refer to Section Test Set Test Set Software VIII Service Software Day code Day code Software Date 99 9 gt SD _ Display Software Date Ni N N Off Off Off Refer to
129. 1 and another is in SSB2 a corrected measurement of noise figure and gain would not yield a valid data point that did not require interpolating calibration data for a frequency between the two calibration points Section VIH Service is in the Service Manual The part number of the Service Manual is on the title page of this manual HP 8970B Comments cont d Operation Error Messages and Recovery conta Special Function 39 1 can be used to disable E21 for interpolated calibration data Special Function 39 0 default after a PRESET enables E21 Error code E27 usually occurs because the noise figure of the measurement system is too high during the calibration of the third input gain setting at one or more calibration frequency Consider the error code as only a warning and that the ability of the instrument to make valid measurements is most likely not impaired But if error code E22 occurs during the actual measurement do one of the following 1 Increase the instrument s smoothing factor and try to recalibrate 2 The DUT probably has 30 dB or more of gain causing the Noise Figure Meter to use the attenuator setting of the third calibration setting Attach a 10 dB attenuator to the output of the DUT and use special functions 34 3 34 4 and 34 1 to correct for the loss 3 Add a preamp to the measurement system and recalibrate Error code E28 is generated when the Noise Figure Test Set needs a fine tuning calibratio
130. 10 100 1000 and 2000 MHz ENR entries to correspond to the noise source ENR chart Exit the ENR table entry mode by pressing the FREQUENCY key On the Noise Figure Meter set START FREQ STOP FREQ and FREQUENCY all to 1000 MHz Set the 10 dB step attenuator for 40 dB of attenuation Set the 1 dB step attenuator for a power level no greater than 48 dBm as read on the power meter On the Noise Figure Meter press INCREASE to set the smoothing factor to 8 Press CALIBRATE twice When calibration is complete key in 81 0 SPECIAL FUNCTION to turn on the noise source and display the noise power detector output in volts voltmeter mode Press STORE 1 to store this setting in the instrument memory Set a relative reference on the power meter Press d BREL key on HP 436A Press NF and GAIN keys Set the step attenuator for 30 dB of attenuation Note the power meter reading Power Meter 10 dB Gain m AB On the Noise Figure Meter press NOISE FIGURE AND GAIN Note the Insertion Gain reading Noise Figure Meter 10 dB Gain ___ ss dB On the Noise Figure Meter press RECALL 1 Set the step attenuator for 20 dB of attenuation Note the power meter reading Power Meter 20 dB Gain __ CBB On the Noise Figure Meter press NOISE FIGURE AND GAIN Note the Insertion Gain reading Noise Figure Meter 20 dB Gain BB Insert a 20 dB attenuator into the setup at the input to the power sensor On the Noise Figure Meter press RECALL 1
131. 2 Measurement System Internal IF for SSB3 Internal IF Fixed IF or LO Frequency Selection Internal IF for DSB Display Noise Figure Meter input frequency ZZ Z Z Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 3 242 l ap EARE B p trm namn HP 8970B Operation Table 3 14 Special Function Summary 5 of 15 w w an ke T E we a t Sz 5E Ep ES SS zs v peniad g Special Function Program Ze S AS S 58 2S v2 e2 eel mS es References and Code Description BE sacr gS SE gs Comments Name code ZEEE S2 8 85 4S ES a2 Recorder Functions Go to Lower Left Go to Upper Right Plot Noise Figure Plot Gain X AXIS Output is Noise Figure and Y AXIS Output is Gain Strip Chart mode Data Output to Oscilloscopes Recorders and Plotters ZZZzzz qt Zz Data Output to Oscilloscopes Recorders and Plotters LL UR A4 A5 A6 PA Plotter 25 0 Plot grid and data N iNi N Off Off Off Data Output to Functions 25 1 PG Plotgridandaxeslabels N N N loft off ofp Oscilloscopes Recorders and 25 2 PD Plot data only N IN N Off Off Off Plotters 25 3 NP Select noise pen number N N NNC 1 1 25 4 GP Select gain pen number NiNi N NC 2 2 25 5 WT Select plot name NIN N NC HP HP 89
132. 25 Example p Perform a SINGLE or AUTO sweep to gather data for the plot cont d NOTE The plot will be aborted if an HP IB command is sent to the Noise Figure Meter or a front panel key is pressed during the plot q Start the plot by using Special Function 25 0 25 1 or 25 2 NOTE If Special Function 7 1 test pattern was selected earlier and Special Function 25 0 25 1 or 25 2 has been selected the plotter will not produce a plot If the Noise Figure Meter measurement is UNCORRECTED the gain curve will not be plotted r The plotted traces will be the same as the traces that were displayed on the oscilloscope Outputting Data to a Plotter on the Hewlett Packard Interface Bus gt NOTE The controller should be able to accept a very large string on the order of 1000 to 6000 bytes or more depending on the number of points that are to be plotted In general the controller should be able to accept the number of points as described in the following equation Number of points 1000 12 The total number of noise figure and gain points s Connect the controller and the plotter to the HP IB connector on the Noise Figure Meter t Special Function 47 1 plot data is on HP IB must be active u The address of the plotter must match the address that the controller will use later to send data to the plotter NOTE If the controller sends a command to the Noise Figure Meter when it is expecting to have a plot read
133. 3 83 Display Units Selection 0 005 3 85 Smoothing Averaging 000 3 230 Temperature Units Selection 3 271 ENR ENR Table Entry 00 cccceseeeeee 3 87 Loss Compensation c ccceeeees 3 119 Spot ENR Thot Teold and ENR Table Selection cccccccceaceeees 3 254 Temperature Units Selection 3 271 HP IB and SIB Controller Capability of the Noise Figure Meter isisiescexiandeses vas sa swndte 3 71 HP IB and System Interface Bus SIB Addresses souesseoravoronensrrsns 3 113 System Interface Bus Control 3 262 Measurement Modes Fixed IF or LO Frequency Selection 3 110 Loss Compensation 000e0eee 3 119 Measurement Modes ccceeeueee 3 125 Measurement Mode 1 0 000 3 132 Measurement Mode 1 1 0 3 135 Measurement Mode 1 2 3 140 Measurement Mode 1 3 0000e 3 145 Measurement Mode 1 4 cecens 3 150 Measurement Mode 1 5 cccceee 3 155 Measurement Mode 1 6 cccecens 3 160 Measurement Mode 1 7 2 000 3 168 Measurement Mode 1 8 005 3 176 Measurement Mode 1 9 000 3 183 Sideband Selection cccceeecces 3 226 Measurements Manual Measurement Functions 3 121 Noise Figure Uncorrected and Noise Figure and Gain Corrected 3 198 3 6 Section Page Measur
134. 3515 amp 3 Code gz 1B se 38 s 123 Description Coe zd 2 22 82 88 E32 2 Auxiliary Commands AC or 42 0SP NC NC CW Prefix and Suffix PS or 42 1SP Settling Time in ms TM or 42 2SP Minimum Frequency in MHz MN or 42 3SP Maximum Frequency in MHz MX or 42 4SP Output Signal Power Level PL or 42 5SP 3 214 Programming The System LO contd Special Function 42 Power Prefix and Suffix Special Function 41 5 Frequency Prefix and Suffix Special Function 41 5 PC or 42 6SP zZz Z ZZZZZZ O E Ad e l Zw AZZZ Z lt FC or 42 78P Table categories are explained in the Special Functions Detailed Operating Instruction Entering Data Special Function 42 0 allows for modification of the auxiliary commands of the program stored in temporary memory If one of the predefined system LO programs is to be modified Special Function 41 0 through 41 5 should be activated first to ensure that the correct program is in the temporary memory An auxiliary command is simply an HP IB program code required to control one function of the system LO Each program code consists of one or more ASCII character The decimal equivalent of each ASCII character is stored in one of the fifteen data locations available for auxiliary commands The general procedure for entering data using Special Function 42 0 is as follows a Determine what system LO functions are to be c
135. 4 2 is activated in step j i Remove the hot noise source and connect the cold noise source to the measurement system setup j Press 14 2SPECIAL FUNCTION to select the hot noise source measurement and to store the cold noise source calibration reading Measure then Calculate and Display Noise Figure k Connect the hot noise source to the DUT and the DUT to the measurement system setup l Press 70 0 SPECIAL FUNCTION to allow the IF attenuators to autorange m Press 72 0 SPECIAL FUNCTION to hold the IF attenuation fixed at the new value n Press 14 1 SPECIAL FUNCTION to select the cold noise source measurement and to store the hot noise measurement reading o Disconnect the hot noise source from the DUT and connect the cold noise source to the DUT HP 8970B Example contd Program Codes cz indications Comments Related Sections Operation Manual Measurement Functions cont d Special Functions 14 and 15 p Press 15 1 SPECIAL FUNCTION to calculate and display the manual meas urement noise figure result Verify that the LED in the SPECIAL FUNCTION key lights when this special function is activated The Noise Figure Meter continues to make cold noise source measurements and update the display NOTE The calibration data remains stored Therefore if another DUT is to be tested immediately it is only necessary to press 14 2 SPECIAL FUNC TION and repeat steps k through p To exit manual measurements and
136. 70B 8970B Noise Noise Figure Figure Meter Meter On On On Off Off Off Off Off Off Free Run Hold Execute Trigger Selection Trigger Selection 2 224 2 Ziz ZZ 2 2224 Frequency Automatic On On On Calibration Calibration Frequency Display Frequency Cal Off Off Off Perform 1 Frequency Cal 20 10 and0dB 10 0 and 10 dB 0 10 and 20 dB 10 20 and 30 dB Input Gain Calibration Calibration Input Gain Selection Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 3 243 Operation HP 8970B Table 3 14 Special Function Summary 6 of 15 Special Function Program References and Comments Lights Special Function Key tinuous Memory Can be Stored and Recatied Special Functions 0 8 Conditions Preset and HP iB Clear Conditions Spectal Function 0 8 Conditions LA LT Sequence Functions Noise Figure Test Set YIG Filter Fine Tuning Calibration Code Description Mme owe ca IF Attenuators See footnote Calibrate IF Attenuators N Y N Off Off Off Calibration IF Calibration below Attenuators Lo Off Loss Compensation Li On Enter Loss before DUT in dB Enter Temperature of Losses Enter Loss after DUT in dB Manual Automatic Set Clear Enable Fine Tuni
137. 8970B HP 8970B indications Measurement Mode and Sideband Selection Related Sections Operation Measurement Modes conrad Special Function 1 Noise Figure Meter Left Display Wand 15 1and1 6 L2and 1 7 1 3andt 8 1 4and19 Fagna F Fio IF not LO allowed Fio IF Fio IF Fo IF IF Fio IF Fo IF Fo IF IF Fo IF Fu IIF Fo Selected Sideband Double Sideband 2 0SP Lower Single Sideband 2 1SP Upper Single Sideband 2 2SP Sum up conversion 2 3SP Prior to making any measurement the Measurement Mode and sideband operation that are best suited to that specific measurement must be chosen Each of the Detailed Operating Instructions for Measurement Modes 1 0 through 1 9 has valid examples of the type of measurements that are made in each mode Calibrate ENR Table Entry Fixed IF or LO Frequency Selection Measurement Modes 1 0 through 1 9 Sideband Selection 3 131 Operation Description Procedure Example 3 132 4il OJJ VL Measurement Mode 1 0 Special Function 1 0 Measurement Mode 1 0 provides direct noise figure and gain measurements in the frequency range of 10 to 1600 MHz No external mixer or LO is required All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements In addition
138. 99 MHz Modes 1 5 through 1 9 require use of the Noise Figure Test Set and the system LO Along with the Noise Figure Meter the Noise Figure Test Set and the system LO form the Noise Figure Measurement System which extends the range of the Noise Figure Meter from 1600 to 18000 MHz Modes 1 6 through 1 9 require use of a second LO user controlled The user controlled LO is used with the Noise Figure Measurement System and along with an external mixer extend the range of the Noise Figure Measurement System from 18000 to 99999 MHz Modes 1 6 and 1 7 require an external mixer the mixer is part of the DUT in Modes 1 8 and 1 9 Refer to the operating information pull out card and Mea surement Modes in the Detailed Operating Instructions for more information A Measurement Mode must be selected before performing a calibration or measurement Mode 1 0 is selected with PRESET Simplified Operation assumes that Mode 1 0 is selected FIXED FREQUENCY TUNING Fixed frequency parameters are selected in a Function Data ENTER frequency to 500 MHz and the even frequency increment to 100 MHz FREQ _ press iii Soo O we e steps the frequency up or down by the 100 MHz increment set with the FREQ INCR key format For example to set the tuned DATA or SG STORE AND RECALL The Noise Figure Meter can store instrument configurations for recall at a later time F instrument configuration in storage reg
139. ALE NOISE MAX or press 8 2 SPECIAL FUNCTION or send HP IB code NU The default value is 8 000 dB To change the upper limit to 4 dB press 4 and ENTER or send HP IB code 4EN 3 75 Operation HP 8970B Data Output to Oscilloscopes Recorders and Plotters contd Special Functions 7 8 and 20 through 25 Example g In a similar manner use front panel key GRAPHIC SCALE GAIN MIN 8 3 cont d SPECIAL FUNCTION or HP IB code GL and front panel key GRAPHIC SCALE GAIN MAX 8 4 SPECIAL FUNCTION or HP IB code GU to display and change the lower and upper limits of the gain trace The default values of 0 000 and 40 00 are satisfactory for this example h To display the corrected swept measurement press CORRECTED NOISE FIG URE AND GAIN or send HP IB code M2 i For a repetitive swept measurement beginning at the start frequency press START FREQ and then AUTO or send HP IB codes FAW1 Verify the display is similar to that shown below There should be a noise figure trace and a gain trace Swept Measurement on Oscilloscope NOTE If desired the intensity of the gain trace can be adjusted relative to the noise figure trace This can be done by turning the GAIN TRACE adustmenti on the rear panel of the Noise Figure Meter see Figure 3 8 j To stop the sweep press AUTO again or send HP IB code W0 Note that a different HP IB code is required to turn off the sweep since this function cannot be toggled over the HP IB NOTE S
140. AND ACCURACY PERFORMANCE TEST cont d Procedure cont d 29 Fillin the table below using the readings from the appropriate steps above For the column on the far right square the readings in the previous column Voltmeter Noise Figure Meter Readings Readings er rag OO ve O woo ao w l a es C sw o ey ee Coan oee ony O sws ooo l e S C swn oo l e U wn o ee Cea el 30 Fill in the table below by computing the indicated ratios Y Factors The ratios of the second set of columns should be computed from the squared voltages from the previous table Subtract the ratios of the second set of columns from those of the first set to yield the net error difference The result should be within the indicated limits Ratios cata Step 10 LERNINDA 0 00053 0 00054 Step 16 0 00589 0 00603 Step 10 Step 19 0 04922 0 05037 Step 10 0 20964 0 71330 0 71330 Step 9 Step 13 Step 10 Step 12 Step 9 Step 15 Step 9 Step 18 Step 9 Step 22 Step 10 Step 21 Step 9 Step 25 Step 19 Step 24 Step 18 Step 27 Step 28 4 9 Performance Tests HP 8970B PERFORMANCE TESTS 4 8 GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST Specification Description Equipment GAIN MEASUREMENT CHARACTERISTICS Range 20 to gt 40 dB Instru mentation Uncertainty 0 15 dB The Noise Fig
141. B Code Summary for applicable HP IB codes f Perform a triggered Noise Figure Test Set Fine Tuning Calibration and Noise Figure Measurement System Calibration with the DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction and the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction A Noise Figure Test Set Fine Tuning Calibration may need to be done separately from the measurement system calibration The separate fine tuning calibration is needed if a mixer is being used out in front of the Noise Figure Measurement System and a preamplifier is not being used An ENR Excess Noise Ratio of 13 dB or greater is needed at the input to the Noise Figure Test Set during the fine tuning calibration 3 165 Comments cont d 3 166 Operation Measurement Mode 1 6 contra Special Function 1 6 g Set the Noise Figure Meter s calibrate function on HP IB code is CA h Set the user controlled local oscillator to the desired frequency depending on the sideband selection If double sideband was selected the oscillator should be set to the measurement frequency If lower sideband was selected the oscillator should be set to the measurement frequency plus the IF If upper sideband was selected the oscillator should be set to the measurement frequency minus the IF If sum upconversion Special Function 2 3 was selected set the oscillator to the IF minus the measurement frequency
142. Ctrl OFF For HP IB codes refer to the Procedure above Asa special function code is entered it appears in the left display The code remains there until the SPECIAL FUNCTION key is pressed When the Noise Figure Meter is not the System Interface Bus controller Ctrl appears inthe INSERTION GAIN display and OFF appears in the NOISE FIGURE display When the Noise Figure Meter is in Pass Through Mode PASS appears in the INSERTION GAIN display and thru appears in the NOISE FIGURE display When the Noise Figure Meter is doing a plot Plot appears in the INSERTION GAIN display 3 269 Operation HP 8970B System Interface Bus Control conta Special Functions 45 through 49 Comments The following program example shows how an external controller would request that the Noise Figure Meter perform a serial poll of a device on the System Interface Bus SIB NOTE The following example assumes that the address of the Noise Figure Meter is 708 and the address of the device on the SIB to be polled is 19 This program was written in BASIC language 3 0 using the HP sc Series 200 Model 236 computer 10 Spoll Serial poll of device on the Noise Figure Meter System Interface Bus 20 Addr 19 tAddress of device on SIB to be polled 30 OUTPUT 708 SB Addr EN Tell Noise Figure Meter ito poll device on SIB 40 OUTPUT 708 H1 Output frequency insertion igain and noise figure windows 50 OUTPUT 708
143. DE THEY NEED TO BE USED DURING CALIBRATION NOTE A Noise Figure Test Set Fine Tuning Calibration may need to be done separately fram the measurement system calibration step h The sep arate fine tuning calibration is needed if a mixer is being used out in front of the Noise Figure Measurement System and a preamplifier is not being used An Excess Noise Ratio ENR of 13 dB or greater is needed at the input to the Noise Figure Test Set during the fine tuning calibration h Calibrate and fine tune in Measurement Mode 1 6 by performing a triggered calibration The user controlled local oscillator frequency must be set up before the Noise Figure Meter is triggered PRESET enabled a fine tune Special Function 36 0 to be done each time a calibration is done Enable the calibration and fine tune by pressing the CALIBRATE key twice i To make the measurement set up the equipment as shown below OUTPUT PREAMPLIFIER EF NEEDED FILTER eTHE FILTER f ADDED IF A SINGLE SIDEBAND MEASUREMENT IS BEING MADE HP 8970B Example cont d Program Codes Indications Comments Operation Measurement Mode 1 6 conta Special Function 1 6 NOTE For the Noise Figure Measurement System specifications to be valid the measurement must use the same START FREQ STOP FREQ and STEP SIZE that was used for calibration None of the calibrated points can be skipped Also the measurement must be done in the same direction as the ca
144. ECTED NOISE FIGURE AND GAIN STORE and RECALL are also used to store or recall an ENR table HP 8970B When the STORE key is used as a prefix for a numeric key a single digit 0 9 to identify the register the current instrument configuration is stored in that internal storage register When the RECALL key is used as a prefix to a numeric key a single digit 0 9 to identify the register the contents stored in that register are recalled and the instrument configuration is changed to the recalled parameter values O SEQ Key Recalis storage registers 1 through 9 in a preset sequence Pressing the SEQ key momentarily displays the current storage register number SEQ is used in conjunction with Special Function 35 6 Minus Key Can be used as a prefix for loss ENR or temperature Although the minus key can be used any time before an entry is completed the minus sign is always inserted to the left of the entered digits If the minus sign is used incorrectly an error message is displayed when ENTER is pressed Figure 3 6 DATA and SPECIAL FUNCTION Features HP 8970B Operation i BRL A SUREMENT ose Bocuse CALIBRATE Key initiates the calibration process which measures and stores the measurement system noise figure and gain This data is used for second stage correction and gain measurements Calibration is done from START FREQ to STOP FREQ in steps of STEP SIZE see Figure 3 5 During calibration all fr
145. ERTION GAIN NOISE FIGURE CR LF EOI is set each time LF is sent The HP IB output has one more digit of resolution than the front panel display except for the voltmeter mode which has two more digits of resolution than the front panel NOISE FIGURE display Error Output Format 90D DDE 06CRLF Line Feed Error Code Carriage Return The Noise Figure Meter will output special HP IB codes for the NOISE FIGURE window when a read of the Noise Figure Meter is attempted during the following operations ENR editing ENR cata 3 38 HP 8970B log Noise Figure Test Set Coarse or Fine Tuning Calibration The special HP IB codes are given below ENR Editing 80 TNNE 06 Fixed Data a Fixed Exponent ENR Table Number ENR Tabie Entry Number ENR Catalog 80 TNNE 06 Fixed Data Fixed Exponent ENR Table Number Total Number of Entries in the Table Noise Figure Test Set Fine Tuning Calibration 80363E 06 Fixed Data Fea Exponent Special Function number for a Fine Tuning Calibration Noise Figure Test Set Coarse Tuning Calibration 80640E 06 Fixed Data _ Specia Function number for a Coarse Tuning Calibration Fixed Exponent One purpose for these special codes would be to read back from the Noise Figure Meter until the codes stop being sent which would mean the task is complete This would be useful when doing a coarse or fine tune calibration Timeouts should not be used with these special codes If a
146. ESET for some of the special functions Table 3 14 Special Functions Summary in the Special Functions Detailed Operating Instruction provides a complete list of Special Function 0 9 and PRESET conditions for special functions In the Program Code column in Table 3 12 program codes that are equivalent to front panel keystrokes are listed HP IB codes control the Noise Figure Meter s functions over the HP IB The Stored in Continuous Memory column in Table 3 12 indicates whether or not the status of a front panel key is retained when the Noise Figure Meter is turned off The Can Be Stored and Recalled column in Table 3 12 indicates whether or not the status of a front panel key can be stored in an internal storage register for recall at a later time 3 205 Operation HP 8970B Preset Conditions and Power Up Sequence contd includes Special Functions 0 0 and 0 9 Table 3 12 Front Panel Summary ss oa x p Sx amp S pou ZES SE 3 ESE Progam 2E S2 Sse Front Pane Key Code ran Zig E REZ References and Comments 5 w 30 PY Bz SE HES AUTO Sweep N N Sweep CALIBRATE N N Calibrate DECREASE Y N Smoothing ENTER _ General Operating Instructions ENR Y N ENR Table Entry FREQ INCR Y Y Fixed Frequency Increment Fixed Frequency Increment ie Fixed Frequency Increment FREQUENCY Fixed Frequency Tuning INCREASE Smoothing
147. Figure Meter Use Special Function 40 2 Noise Figure Test Set System Interface Bus address to display and change this address if necessary The default address for the Noise Figure Test Set is 10 after using Special Function 0 9 e Special Function 46 0 must be active Enable system local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 f The address of the system local oscillator must match the address of the system local oscillator stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator System Interface Bus address to display and change this address if necessary The default address is 19 after using Special Function 0 9 g The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below e HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 HP 8673B C Standard Synthesized Signal Generator Special Function 41 3 o HP 8340B 8341B Sweep Oscillator Special Function 41 4 e Custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or o
148. G tuned filter fine peak calibration 36 3 SPECIAL FUNCTION or 36 4 SPECIAL FUNCTION and error E 27 will result when trying calibrate the noise figure meter with 36 1 SPECIAL FUNCTION active DiSapIg YIG Tune in Cal This applies to the HP 346A Noise Source oniy Using the HP 346A Noise Seurce with ihe HP 8970A B A preamplifier may be required when using the HP 346A Noise source to calibrate the HP 8970A B Noise Figure Meter if error E 27 occurs after pressing the CALIBRATE key on the noise figure meter use a preamplifier to correct the situation Typically a Pieemnley with gt 10 dB of gain and lt 6 dB noise figure will work HP 8970B Section I GENERAL INFORMATION Introduction nneseserosesesesesesso Specifications sesensesesseresssseuu Safety Considerations c cceeeeeeues Instruments Covered by Manual Manual Changes Supplement Description asseserecsrenecsrroererees Noise Figure Meter ccecaeeee Noise Figure Measurement System Mechanical Options ccccusaccees Front Handle Kit Option 907 Rack Flange Kit Option 908 Rack Flange and Front Handle Combination Kit Option 909 Hewlett Packard Interface Bus HP IB Compatibility sssssnsarsssosssesrssa Selecting the HP IB Address System Interface Bus SIB 0 065 Compatibility onsasann
149. H is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 45 Operation HP 8970B C HP IB SYNTAX AND CHARACTERISTICS SUMMARY con d Status Byte a a e E a a _ Service Extended RQS Bit Instrument Received SRQon HP IB Noise Figure Data Request Status Require Error Control System Meter Condition Byte Service on SIB Interface Calibration Bus Complete The condition indicated in bits 0 5 and 7 must be enabled to cause a Service Request by Special Function 44 Each condition can be enabled separately or all conditions can be enabled at once using Special Function 44 7 2 The RQS bit bit 6 is set true whenever any of the conditions of bits 0 5 and 7 are enabled and occur For bit 7 to be enabled both the Extended Status Byte mask and Special Function 44 8 must be enabled Service Request Condition Calibration Calibration Test Set Test Set Test Set Completed Completed needs needs Coarse Fine Tuning Fine Tuning Tuning at Current Calibration Frequency Special Function 36 3 The conditions indicated in bits 0 through 6 must be enabled to cause a Service Request by Special Function 44 9 Special Function 44 9 enables all the conditions desired at once The procedure is to press 44 9 SPECIAL FUNCTION enter the total binary weights of the conditions desired and press ENTER Special Functi
150. IG Filter Calibration Detailed Operating Instruction NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement un certainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selec tion Detailed Operating Instruction 3 161 aam woo w ar t aata PA WS WAS Measurement Mode 1 6 contd Special Function 1 6 Procedure a Verify that the minimum requirements specified under Requirements are satisfied cont d b Press PRESET c Press 1 6 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 6 d Set frequency parameters including the fixed IF Special Function 3 0 e Select sideband operation desired Special Function 2 and 17 f Select appropriate smoothing Special Function 193 g Enter the ENR table of the noise source h Perform a Noise Figure Test Set fine tuning calibration For more information refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction i Perform a triggered calibration of the Noise Figure Measurement System with the device under test DUT out of the measurement system in Mode 1 6 this is only required for a CORRECTED NOISE FIGURE AND GAIN measurement The use
151. IOUS RESPONSE PERFORMANCE TEST Specification SPURIOUS RESPONSE Change in noise figure lt 0 03 dB for spurious levels below 45 dBm in the 10 to 2100 MHz range and 15 dBm in the 2 1 to 18 GHz range Description The signal generator power level is adjusted to give the desired power out of the directional coupler Noise figure readings are taken at several frequencies with the signal generator power on and off The difference between the two readings should be less than 0 03 dB Equipment Attenuator 10 dB 46 s oiisns eis eae han eees HP 8491A Opt 010 Directional Coupler 0 cc eee eee HP 778D Noise Source 2cccuccecccecsceceens HP 346B Opt 001 Power Meter ccccccnescscesseceres HP 486A Power Sensor ccecccscccvccesenscvevece HP 8484A Signal Generator ccc en ee eee eee HP 8614A HP 8970B NOISE FIGURE METER POWER METER POWER SENSOR SENSOR STEP 7 STEP 4 h gR i 10 dB ATTENUATOR SIGNAL GENERATOR RF OUTPUT Figure 4 5 Spurious Response Test Setup Procedure i 1 Set the signal generator frequency to 1380 MHz 2 On the Noise Figure Meter press PRESET then key in 13 1 SPECIAL FUNCTION Cae CIAL FUNCTION and 32 ENTER to set the arithmetic smoothing factor 3 On the Noise Figure Meter set FREQUENCY to 500 MHz 4 Connect the equipment as shown in Figure 4 5 5 On the Noise Figure Meter key in 80 0 SPECIAL FUNCTION to turn the noise source off 6 Adjust the si
152. ITI for additional information 1 16 SYSTEM INTERFACE BUS SIB The System Interface Bus is a private bus used by the Noise Figure Meter to control the Noise Figure Test Set the System Local Oscillator anda plotter General Information 1 17 Compatibility The System Interface Bus is compatible with IEEE Standard 488 1978 to the extent indi cated by the following codes SH1 AH1 T6 TEO L4 LEO RL1 PPO DC1 DTO C1 C2 C3 C4 C7 and El The Noise Figure Meter interfaces with the bus via open collector TTL circuitry An explanation of the compatibility code can be found in IEEE Standard 488 1978 IEEE Stan dard Digital Interface for Programmable Instru mentation or the identical ANSI Standard MC1 1 1 18 Selecting the SIB Address The Noise Figure Meter uses SIB addresses for the following e System Local Oscillator Noise Figure Test Set Plotter System Interface Bus Pass Control Pass Through Device on the SIB For more information on selecting the SIB addresses refer to the HP IB and System Interface Bus SIB Addresses Detailed Operating Instruc tion in Section III 1 19 ACCESSORIES SUPPLIED The accessories supplied with the Noise Figure Meter are shown in Figure 1 1 a The line power may be supplied in several configurations depending on the destination of the original shipment Refer to paragraph Power Cables in Section H of this manual b Fuses with a 1 5A rating for 100 120 Vac
153. Measurement System consists of the Noise Figure Meter the HP 8971B Noise Figure Test Set and a System Local Oscillator All the features described about the Noise Figure Meter apply to the Noise Figure Measurement System with the following changes The Noise Figure Measurement System can be tuned between 10 and 18000 MHz The noise figure of devices with output fre quencies greater than 18000 MHz can be measured with the addition of an external mixer and a second user controlled local oscillator double down conversion Measurements using interpolated calibration data are not allowed for measurement modes 1 5 through 1 9 unless a special function has been selected For simplicity the Noise Figure Measurement System can be thought of as one instrument The Noise Figure Meter s System Interface Bus is used to control the Noise Figure Test Set and the System Local Oscillator 1 9 MECHANICAL OPTIONS The following options may have been ordered and received with the Noise Figure Meter If they were not ordered with the original shipment they can be ordered from the nearest Hewlett Packard office using the part number included in each of the following paragraphs HP 8970B MECHANICAL OPTIONS cont d 1 10 Front Handle Kit Option 907 Ease of handling is increased with the front panel handles Order HP part number 5061 9689 1 11 Rack Flange Kit Option 908 The Noise Figure Meter can be solidly mounted
154. Meter During serial poll the Require Service message is cleared immediately before the Noise Figure Meter places the Status Byte message on the bus There are seven conditions that can be enabled to cause the Require Service message to be sent when they occur All seven conditions are described as follows Operation 1 Data Ready When the Noise Figure Meter is ready to send any information except error codes 2 HP IB Code Error When the Noise Figure Meter receives an invalid Data message Un less specifically disabled this condition causes a Require Service message to be sent 3 Instrument Error When any operator error E10 through E49 and E99 is displayed by the Noise Figure Meter 4 Calibration Complete When a Noise Figure Meter calibration cycle is complete 5 System Interface Bus SRQ When an instru ment on the System Interface Bus is issuing a Service Request SRQ 6 Received Control of the System Interface Bus When the Noise Figure Meter has taken con trol of the System Interface Bus 7 Extended Status Byte When one of the en abled bits on the Extended Status Byte is true 3 30 Enabling the Service Request Condition Use Special Function 44 or the related Service Request Condition HP IB codes to enable the Noise Figure Meter to issue the Require Service message on any of the conditions above The Ser vice Request Condition Special Function is entered from either the front panel or via the
155. NC No Change Not Applicable Special Function 4 1 is no longer used Refer to Special Function 46 3 240 HP 8970B Operation Table 3 14 Special Function Summary 3 of 15 References and Bescription Comments Lights Special Function Key tinuous Memory Can be Stored and Recalled Special Functions 0 0 Conditions Preset fand HP IB Clear Conditions Special Function 0 9 Conditions Stored in Con Special Function Enter Oscilloscope Limits Noise Figure Lower Limit Noise Figure Upper Limit Gain Lower Limit Data Output to Oscilloscopes Recorders and Plotters Gain Upper Limit Power Measurements Power Measurements SOURCE Off uncal SOURCE On uncal SOURCE Off cal SOURCE On cal A a i Noise Figure Display Units 10 1 Nl F Display Units of off off Selection 10 2 N2 YdB 10 35 N3 Y 10 4 N4 TeK 11 0 DO K 11 1 DI C 11 2 D2 F Select Noise Source Temp Units for Data Input On On On Off Off Off Off Off Off Temperature Units Selection Also see Special Functions 5 4 6 0 and 34 3 224 4224242422 4242424 Maximum Resolution Less Res on Noise Figure Less Res on Gain Display Resolution Display Resolution Off Off Off Off On Off Smoothing Averaging O 5
156. NCR 300 ENTER Press Verify that the left display shows 800 MHz and the NOISE FIGURE display shows error code E21 current frequency is out of calibrated range Press Verify the left display shows 500 MHz and the INSERTION GAIN and NOISE FIGURE displays show approximately 0 ENR Table Entry Check 29 30 3l 3 18 NOTE This check verifies the capability of the ENR and ENTER keys to initiate and sequence through the ENR table If it is necessary to change the ENR table refer to the ENR Table Entry Detailed Operating Instruction Press ENR Verify the MHz annunciator in the left display is flashing Press ENTER Verify that the MHz annunciator remains on and the dB annun ciator in the INSERTION GAIN display is flashing Press and hold ENTER Verify the two displays sequence through the ENR table entries Also the ENR table entry should be changing in the NOISE FIGURE display Release ENTER HP 8970B Operation OPERATOR S CHECKS Basic Functional Checks cont d Procedure cont d 32 NOTE If ENTER is held down until all 35 frequency vs ENR pairs have been displayed both annunciators light and remain lit When ENTER is released the Noise Figure Meter returns to the measurement config uration it was in prior to pressing ENR If ENTER is released prior to displaying ali pairs press FREQUENCY to return to the previous measurement configuration Verify that the CORRECTED NOISE FIGURE AND GAIN an
157. NTER to advance to the next step of the sequence After all nine registers have been displayed the Noise Figure Meter returns to normal measurement Pressing the FREQUENCY key at any time terminates setting the sequence To select the manual sequence mode key in 35 0 SPECIAL FUNCTION The instrument steps through the defined sequence one step at a time each time the SEQ key is pressed When the end of a sequence is reached it starts over To select the automatic sequence mode key in 35 1 SPECIAL FUNCTION Press the SEQ key to start automatic sequencing The instrument starts a continuous recall of registers in the predetermined sequence To stop an automatic sequence press the SEQ key again To clear the sequence that is set the sequence to 000 000 000 key in 35 3 SPECIAL FUNCTION To set the sequence to 1 through 9 in order press PRESET m n spi ef 22 2 Ze o E eo amp m ze O amp Sg g EE 55 p S Special Function Program s EVIS E 8 amp 3 t5 Code Eg BE 2218S Se 86 m amp 2 oc ts e e e Description CA gt SP 62 881 2a 6 as Manual Sequence Automatic Sequence Set Sequence Clear Sequence QM or 35 0SP QA or 35 1 SP QS or 35 28P QC or 35 3SP Enables Special Function key LED to light when SEQ is pressed Table categories are explained in the Special Functions Detailed Operating Instruction HP 8970B Example Program Codes a gt in
158. Note the power meter reading Power Meter Reference dB On the Noise Figure Meter press NOISE FIGURE AND GAIN Note the Insertion Gain Reading Noise Figure Meter Reference dB On the Noise Figure Meter press RECALL 1 Performance Tests HP 8970B PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure 45 cont d 46 47 48 49 50 51 52 Set the step attenuator for 10 dB of attenuation Note the power meter reading Power Meter 30 dB Gain dB On the Noise Figure Meter press NOISE FIGURE AND GAIN Note the Insertion Gain reading Noise Figure Meter 30 dB Gain ________ dB On the Noise Figure Meter press RECALL 1 Set the step attenuator for 0 dB of attenuation Note the power meter reading Power Meter 40 dB Gain sd BB On the Noise Figure Meter press NOISE FIGURE AND GAIN Note the Insertion Gain reading Noise Figure Meter 40 dB Gain dB Subtract the reading of step 42 from that of step 38 This is the value of the 20 dB attenuator as seen by the power meter 20 dB Attenuator dB Subtract the reading of step 43 from that of step 39 This is the Noise Figure Meter reference correction factor Noise Figure Meter Correction Factor _________ dB Fill appropriate values into the following table then subtract the values for the Noise Figure Meter fr
159. ON to switch in the internal 30 dB attenuator Take 10 voltmeter readings Then calculate and record the average of the readings Vavg 30 dB Compute the 30 dB attenuator value as shown Result from step 16 Vref8 Vavg 80 dB mmm gt 841 4 lt 1188 5 for 30 dB attenuator 4 13 Performance Tests HP 8970B PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure 22 On the voltmeter select internal triggering If the voltmeter has filtering turn it off cont d Reduce the 10 dB step attenuator by 10 dB and adjust the 1 dB step attenuator until the voltmeter reads as close to 1 volt as possible On the voltmeter select single triggering If the voltmeter has filtering turn it on Take 10 voltmeter readings Using at least four digits to the right of the decimal point calculate and record the average of the readings This is the reference voltage for the 35 dB attenuator calculation Vref4 23 On the Noise Figure Meter press 70 8 SPECIAL FUNCTION to switch in the internal 35 dB attenuator Take 10 voltmeter readings and then calculate the average of those readings Record the average Vavg 35 dB 24 Compute the 35 dB attenuator value as shown Result from step 21 Vref4 Vavg 85 dB mmm 2660 7 lt 8758 4 for 35 dB attenuator 25 Enter the measured attenuator values in Table 4 1 Table 4 1 IF Attenuator Values Measured Value sw ae Ten Entering IF Attenuator
160. OPERATING MANUAL HP 8970B NOISE FIGURE METER Including the HP 89708 Noise Figure Measurement System Sue w z Le Ket AR ee Leggo a E a a Cimo de eenah ae marar ne 7 a a Ze 27 amp utd ee r a Co OW S Ee al SERIAL NUMBERS This manual applies directly to instruments with serial numbers prefixed 2645A For additional important information about serial numbers see INSTRUMENTS COVERED BY MANUAL in Section I Li HEWLETT PACKARD Copyright HEWLETT PACKARD COMPANY 1987 1501 PAGE MILL ROAD PALO ALTO CALIFORNIA U S A Operating Manual Part No 08970 90022 Operating Manual Microfiche Part No 08970 90024 Service Manual Part No 08970 90023 Service Manual Microfiche Part No 08970 90030 Printed MARCH 1987 6 52 5 1 CERTIFICATION Hewlett Packard Company certifies that this product met its published specifications at the time of shipment from the factory Hewlett Packard further certifies that its calibration measurements are traceable to the United States National Bureau of Standards to the extent allowed by the Bureau s calibration facility and to the calibration facilities of other International Standards Organization members WARRANTY This Hewlett Packard instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment During the warranty period Hewlett Packard Company will atits option either repair or replace products which prov
161. OPERATION PLUG SEV 1011 1959 24507 TYPE 12 CABLE HP 8120 2104 PLUG NZSS 198 AS C112 CABLE HP 8120 1369 220 240V OPERATION PLUG DHCK 107 PLUG CEE VII CABLE HP 8120 1689 CABLE HP 8120 2956 HP 8970B This instrument is equipped with a three wire power cable When connected to an appropriate ac power receptacle this cable grounds the instru ment cabinet The power cable plug shipped with each instrument depends on the country of desti nation Refer to Figure 2 2 for the part numbers of the power cables available 2 7 Address Selection GHE The Noise Figure Meter uses HP IB and System Interface Bus SIB addresses The HP IB address is used when the Noise Figure Meter is accessed by an external controller SIB addresses are used when the Noise Figure Meter acts as a controller to access other devices When the Noise Figure Meter is shipped from the factory it assumes that devices are set to the addresses shown in Table 2 1 Both HP IB and SIB addresses are selected by Special Function from the front panel Refer to HP IB and System Interface Bus SIB Addresses and System Interface Bus Control in the detailed operating instructions in Section JHI for additional information Valid HP IB and SIB addresses are 0 through 30 Refer to Table 2 2 for decimal equivalents of the ASCH Talk and Listen address codes 100 120V OPERATION 220 240V OPERATION PLUG NEMA 5 15P CABLE 8120 1378 220
162. Operation Calibration Input Gain Selection Special Function 32 Description The gain setting for calibration can be selected using Special Function 32 Calibration is performed from the start frequency to the stop frequency in steps of the specified step size At each frequency calibration is done at the three most sensitive RF attenuator gain settings that is 20 10 and 0 dB These settings are the default value for Special Function 32 Three other sets of gain settings can be selected using the special functions shown below Selection of the gain settings to be calibrated depends upon the specific application Selecting a calibration gain setting does not initiate a calibration sequence Procedure To select an alternate gain setting for calibration key in the corresponding Special Function code and then press the SPECIAL FUNCTION key es 2 amp Special Function Program S S Code Z c 5 pa oe tinuous Memory Special Function Preset and HP IB Clear Conditions Special Function 0 9 Conditions 0 0 Conditions Lights Special Can be Stored Stored in Con Description Code 20 10 and 0dB 32 0 N N On On On 10 0 and 10 dB 32 1 N N Off Off Off 0 10 and 20 dB 32 2 N N Off Off Off 10 20 and 32 3 N N Off Off Off 30 dB Example To select 10 0 and 10 dB as the gain settings for calibration LOCAL pamanna OGG samme gm FUNCTION mm
163. Output Signal Power Level are still valid when using the Custom Local Oscillator Program Special Function 42 1 is not valid with the Custom Local Oscillator Program The following procedure outlines the steps to be followed when using the Custom Local Oscillator Program a Press 46 1 SPECIAL FUNCTION This disables the system local oscillator commands on the System Interface Bus b Press 41 5 SPECIAL FUNCTION This brings the Custom Local Oscillator Program from permanent memory ROM to temporary memory RAM NOTE Once the parameters for Special Function 41 5 have been selected enabling Special Function 41 5 again will set the default conditions c Press 42 0 SPECIAL FUNCTION Modify the auxiliary commands if desired as described earlier under Entering Data 3 217 Operation Examples cont d 3 218 HP 8970B Programming The System LO conta Special Function 42 d Press 42 2 SPECIAL FUNCTION Enter the settling time of the local oscillator being used e Press 42 3 SPECIAL FUNCTION Enter the minimum frequency of the local oscillator being used f Press 42 4 SPECIAL FUNCTION Enter the maximum frequency of the local oscillator being used g Press 42 6 SPECIAL FUNCTION Enter the count character for the prefix the prefix characters the count character for the suffix and the suffix characters for the output signal power level The prefix and suffix can be found in the local oscillator s operating m
164. P 86738 4 41 4SP HP 8340B 5 41 5SP Custom LO program 5 0 6 60 0 through 60 6 SP 9 63 0SP through 63 5SP 60 Norma display 1 80 0SP Voltmeter Mode Noise Source Off 2 81 0SP Voltmeter Mode Noise Source On 3 233 Operation Procedure Example Program Codes a gt indications Comments Related Sections 3 234 HP 8970B Special Function Catalog conta Special Function 50 To select a specific special function catalog display key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Special Function Program CZ Description Code Description Code tinuous Memory Special Function Preset and KP IB Clear Conditions 0 0 Conditions Lights Special Function Key Can be Stored and Recalled Special Function 6 9 Conditions Stored in Con Sequence through all GO or 50 0SP N N eight lines at once Display Line 1 G1 or 50 1SP N N N Display Line 2 G2 or 50 2SP N N N Display Line 3 G3 or 50 3SP N N N Display Line 4 G4 or 50 4SP N N N Display Line 5 G5 or 50 58P N N N Display Line 6 G6 or 50 6SP N N NO Display Line 7 G7 or 50 7SP N N N Display Line 8 G8 or 50 8SP N N N Table categories are explained in the Special Functions Detailed Operating Instruction To display line 2 of the special function catalog Function TOT Code SEAT ICICI o LOCAL ke
165. P IB code CA f To make the measurement set up the equipment as shown below HP 89708 SYSTEM NOISE FIGURE METER LOCAL OSCILLATOR iO OUTPUT PREAMPLIFIER iF NEEDED DUT MIXER OR RECEIVER 3 152 TIT ANMAN fun neem ds m aa HP 8970B Example cont d Program Codes indications Comments Operation Measurement Mode 1 4 conta Special Function 1 4 g Press CORRECTED NOISE FIGURE AND GAIN or send HP IB code M2 h Press SINGLE or send HP IB code W2 The Noise Figure Meter will sweep from 10 to 1000 MHz in 20 MHz steps After the single sweep is completed the instrument halts The HP IB code for Measurement Mode 1 4 is E4 or 1 4SP The left display shows each IF frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain ofthe DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used to contro the Noise Figure Meter and system local oscillator The following general conditions must be observed when using an external controller a The system local oscillator and the external controller must be connected to the HP IB connector on the Noise Figure Meter b HP IB code H1 must be active c Special Function 46 1 must be active d Special Function 4 0 normal talker and listener must be active Note that thereis no HP IB code for t
166. R IGO INTO ENR EDIT MODE FOR I 1 TON ISEND THE ENR TABLE OUTPUT Nfm Frea T 1 EN Enr T 0 EN PRINT SENDING FREQ ENR VALUES OF Freq T 1 Enr T 1 NEXT I OUTPUT Nim FR IEND ENR ENTRY PRINT PRINT DONE DOWNLOADING THE ENR TABLE END The ENR table is used during both UNCORRECTED NOISE FIGURE measurements and CORRECTED NOISE FIGURE AND GAIN measurements The specific ENR vs frequency data that is used is determined by the stimulus frequency Modes 1 0 and the measurement mode that has been selected Refer to Measurement through 1 9 Detailed Operating Instructions for additional information Special Function 0 9 or PRESET has no effect on data stored in the ENR tables Special Function 0 9 or PRESET sets Table 0 as the table that is used for calibration and the measurement Measurement Modes 1 0 through 1 9 Spot ENR Tho Fooie and ENR Table Selection 3 91 3 92 HP 8970B Description HB IB Output Format Operation Error Messages and Recovery The instrument generates error messages to indicate operating problems incorrect keyboard entries or service related problems The error message is cleared when the error condition is removed The error messages are grouped by error code as follows Error 10 through Error 49 These are operating and entry errors which indicate that not all conditions have been met to assure a calibrated measurement or that an invalid keyboard or HP IB entry has bee
167. REMOTE 7 10 REMOTE 7 enabling the Noise Figure Meter to remote Address the Noise Figure Meter to listen OUTPUT 708 20 OUTPUT 708 T1 completing the Remote message then TI send a Data message placing the Noise Figure Meter in the Trigger Hold mode Send the Trigger message TRIGGER 708 30 TRIGGER 708 40V 0 Address the Noise Figure Meter to talk and ENTER 708 V 50 ENTER 708 V store the data in variable V Display the value of V DISP V 60 DISP V 70 END Operator s Check that both the Noise Figure Meter s REMOTE and TALK annunciators are on Response The controller s display should read the same as the NOISE FIGURE display 3 27 Operation HP 8970B OPERATOR S CHECKS 3 13 Noise Figure Measurement System Check Description Equipment Procedure 3 28 This check will verify proper operation of the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and System Local Oscillator The Noise Figure Test Set and the System Local Oscillator extend the input frequency range of the Noise Figure Meter from 1600 to 18000 MHz Noise Source sccccccsscuccees HP 346B Option 001 1 Set up the Noise Figure Measurement System as shown in Figure 3 11 2 Turn the Noise Figure Measurement System on and press PRESET 3 Verify the following conditions s Special Function 48 0 is active Special Function 45 1 is active Special Function 46 0 is active
168. REQ Features 3 11 Numbers lt 2 rod circn bs ction eeu eageea seas vanes 2 2 3 6 DATA and SPECIAL FUNCTION 2 3 Hewlett Packard Interface Bus and System Foat reb eiee hv ncacatana wae ESTN 3 12 Interface Bus Connections 2 4 3 7 MEASUREMENT and INPUT Features 3 13 2 4 Noise Figure Measurement System 3 8 Rear Panel Features 000000 3 14 Interconnections cc cece eee 2 5 3 9 Basic Functional Checks Setup 3 15 3 10 Test Pattern on Oscilloscope 3 16 3 1 Front Panel Features c 0 0000 3 4 3 11 Noise Figure Measurement System 3 2 Display and Remote Features 3 8 Check Setup 6s ds Suc carer kewsevscesenes 3 28 iv General Cantante Tir sv UuB TIM AAA HP 8970B General Contents ILLUSTRATIONS cont d Page 3 12 Example Flow Chart for Driving the Noise Figure Meter Using the Require Service Figure 4 3 IF Attenuator Calibration Setup 4 4 Gain Measurement Uncertainty ee a Message SRQ SBN ake oka lel TEE EOE 3 43 Test Setup sip b s Sth E E E 65 s isi 6 Die AEEA EEEE 4 5 Spurious Response 4 1 Input SWR Test Setup eseeeeee 4 4 Fest Setup aks eieteVcs ed eoh ia eaa E es 4 2 Noise Figure Instrumentation Accuracy Tost Setup ikon cohol aie cs wae tes bie alee 4 7 TABLES Table Page Table 1 1 Noise Figure Meter Specifications 1 5 3 5 HP IB Data Output Summary 1 2 Noise Fig
169. Range 10 to 1600 MHz Noise Figure Meter 10 to 18000 MHz Noise Figure Measurement System Sweep Linear sweep Range 10 to 1600 MHz Resolution 1 MHz _ Modes Automatic Single Noise Source Drive 28V pulsed Parameters Entry Units ENR in dB C F K Hot Temp Entry Range 363 to 15000K Cold Temp Entry Range 0 to 1000K Smoothing Exponential or linear averaging of insertion gain and noise figure data before result is displayed Selectable units in factors of 2 84NBl4 988 Suiyyoows jo junowe 341 ISVINOIG 10 ISVIYONI S A HNIHLOOWS aniy oes Waysds JUsWaINSeow BU JO sped jje Jo uonqgiguoo asiou apnjou sanea pakgjdsig Juawansesw anhi astou ayy S193438 A9 JUNDA ISION CILIJIJYYCINN LE anbi 899 49491 O1NG14 SiON 94 Olu dm as juaweins gaw AU w04 eUBis ndino y sajdnoo AdN e g aunBi4 998 psaouial Ayeonewoine SI UORNGHIUOI aSioU wWaSAS JUsWaINSesW ay uawauNseaw ueg pue aani asiou ay s 9e es A3 NIVD ONY FUNDI ISION 431934403 2 ainBl4 38S sluBWaINseaw peje 309 U BSN 40 W JS S JUsWEINSRa ay JO AN Hij astou eu sanseaw souanbes siy souend 3S uoneiques e saeu Aey FP WHOITYD e ainBl4 99S 430d 10 edoosoj iaso Ue 10 Buijeos JLI U 188 849 FTYOS JIHdWHY 2 91n6i4 as suo oun4 jelsads Bursn usym aiqissod aie sAeidsip 19010 S81J US 9 42 10 JOQUINU YIM J GUNU ajge HN pue sapo Joie S lun INd NO ajqejaajas
170. Refer to the user controlled local oscillator s operating manual for the required HP IB codes Allow sufficient time for the output of the user controlled local oscillator to stabilize i Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for it will be ignored j A method must be determined when to step to a new frequency after reading the noise figure results This read operation cannot be completed until the new data is ready It is possible to write an SRQ interrupt routine on the Data Ready status bit Refer to Enabling the Service Request Condition paragraph 3 30 k Continue to loop through steps h i and j A method for determining when the calibration will be completed must be programmed into the external controller One method is to compare the frequency that is sent to the user LO with the stop frequency programmed into the Noise Figure Meter and terminate the program after the third measurement in which they are equal It is also possible to write an SRQ interrupt routine on the Calibration Complete Status Bit Refer to Enabling the Service Request Condition paragraph 3 30 L Insert the device under test DUT into the measurement system m Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 n Repeat step h o Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it wi
171. S FOR I t TON f ENTER 708 Reading Read noise figure into Reading Point I Reading t Fill Point array Total Total Reading Build total to get average DISP 14 OF an i x NEXT I i EERE EEE HEHEHE EKER HEHE EE ERE HE HEHEHE ERE EEE KE EEE EERE RHEE ERR ERE ED HERES i Average Total N Perform statistical analysis FOR I TON Quantity Point I Average 2 Quantity NEXT I Jitter S SQR Quantity N 1 t Jitter S x standard deviation f Shows no of readings completed EERTE MERE REE REE EHH ERE EERE EE RARER HER ERE EEE EEERE REE ERERERHEREEHEHHENS i IF Jitter gt Spec THEN 1 Format the output Fail _symS xx FAIL xx ELSE Fail_sym x x PASS xx END IF PRINT s Spec i PRINT USING 418 Jitter Fail_sym IMAGE Z DDD K K i EERE EER EERE EHR EH KEELER ERERHKE HEHEHE RHEE EERE ERRHREREGEEREE HERE EEHREEREREHREHEYE i IF Spec 2 THEN 5i check for end condition i Spec 28 Set variables to test spec with DISP PLEASE WAIT smoothing of 64 OUTPUT 708 13 25P 64EN GOTO Starttest PRINTER IS 1 t Direct output back to terminal END HP 8970B Performance Tests Table 4 2 Performance Test Record 1 of 3 Hewlett Packard Company Tested by Model HP 8970B Noise Figure Meter Serial Number JO Date Results 4 5 TUNING ACCURACY PERFORMANCE TEST Tuned Frequency 10 MHz 8 9 MHz 11 1 MHz 100 MHz 98 MHz 102 MHz 300 MHz 296 MHz 304 MHz 500 MH
172. SS u STEP 5 FILTER oD HP 89708 NOISE FIGURE METER POWER fe BB SPLITTER DIGITAL VOLTMETER 2 cop B BE oo ooo oo BEES pe F r dB ATTENUATOR E Figure 4 2 Noise Figure Instrumentation Accuracy Test Setup Peak the Noise Figure Meter display reading by tuning the signal generator up and down in frequency in 10 kHz increments Increase the signal generator power in 0 1 dB steps until the combined INSER TION GAIN and NOISE FIGURE displays on the Noise Figure Meter indicate as close as possible to 1 00000 volts The signal generator power should be near 14 7 dBm Note this power level as indicated on the signal generator dBm Set the step attenuator for a power meter reading as close as possible to 1 000 pW Set the digital voltmeter to read dc volts on the high resolution setting Using the manual trigger control trigger several readings then stop on a typical reading Note this reading using full resolution Vdc Note the voltmeter mode reading on the Noise Figure Meter also using full resolution Vde Decrease the signal generator power by 0 1 dB Using the same technique as in step 9 take a voltmeter reading Vdc Note the new voltmeter mode reading on the Noise Figure Meter Vdc Decrease the signal generator output power to 1 dB below that set in step 7 4 7 Performance Tests HP 8970B PERFORMANCE TESTS NOISE FIGURE RANGE AND ACCURACY PERFORMANCE TEST cont d Procedure 15
173. Section VIII Service Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable Section VIN Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 253 Operation HP 8970B Spot ENR Thot Teotia and ENR Table Selection Description Procedure 3 254 Special Functions 5 and 6 Special Functions 5 and 6 perform the following functions a Special Function 5 0 enables use of the ENR Excess Noise Ratio data that was previously entered refer to the ENR Table Entry Detailed Operating Instruction This function disables spot ENR Spot ENR can be re enabled using Special Function 5 1 b Special Function 5 1 enables use of the previously entered spot ENR value refer to Special Function 5 3 The ENR table is disabled and the single spot ENR value will be used at all frequencies The ENR table can be re enabled using Special Function 5 0 c Special Function 5 2 enables the current value of ENR being used by the instru ment to be displayed d Special Function 5 3 enables entry and use of a spot ENR value The allowable values for spot ENR range from 7 to 17 dB e Special Function 5 4 enables entry and use of Thor Some noise sources are speci fied in terms of Tho instead of ENR The allowable values for Tyo in Kelvins range from 0 to 14824 The equa
174. Selects modification or N iNi NIO inspection of a word in RAM or inspection of a word in ROM MF Selects modification or NI NIN inspection of a floating point valuein RAM or inspection of a floating point value in ROM Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable Sectiov VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual Operation HP 8970B Table 3 14 Special Function Summary 14 of 15 ee a Program ea Description References and Comments Lights Special Function Key Stored in Con tinuous Memory Can be Stored and Recalled Spectal Functions 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Noise Figure Disable hysteresis cali Refer to Section Meter YIG bration when frequency VIII Service Filter Tuning is changed Functions Enable hysteresis cali bration when frequency is changed YIG DAC is not updated when frequency is changed YIG DAC is updated when frequency is changed Default ENR Sets all ENR values to Refer to Section 15 20 dB and Noise VIII Service Source ID No to 00000 Debug Enables debug Refer to Section Oscilloscope oscilloscope plots VHI Service Plots Disable debug oscilloscope plots Noise Figure i Disable auto sweep Refer to Section Test Set abort error 1
175. System Interface Bus 3 19 Operation HP 8970B OPERATOR S CHECKS Basic Functional Checks cont d Procedure 42 Press 46 0 SPECIAL FUNCTION This will enable the commands for the system cont d LO on the System Interface Bus 43 Press one of the following sequences of keys depending upon the System LO used a For an HP 8350B press 41 0 SPECIAL FONCTION b For an HP 8671B 8672A press 41 2 SPECIAL FUNCTION c Foran HP 8673B C press 41 3 SPECIAL FUNCTION d For an HP 8340B 8341B press 41 4 SPECIAL FUNCTION e For the Custom Local Oscillator Program press 41 5 SPECIAL FUNCTION 44 Press 1 1SPECIALFUNCTION Verify the left display shows 10000 MHz and the EXT MIX annunciator lights Also verify that the remote and listen annunciators light on the system LO 45 On the Noise Figure Meter press SWEEP START FREQ Verify the left display shows 8000 MHz and the System LO is tuned to the same frequency 46 On the Noise Figure Meter press SWEEP STOP FREQ Verify the left display shows 12000 MHz and the System LO is tuned to the same frequency 3 20 HP 8970B Operation zp OPERATOR S CHECKS 3 12 HP IB Functional Checks CHAP Description initial Setup Equipment The following procedures check the instrument s ability to perform the following functions a Process or send all of the applicable HP IB messages described in Table 3 3 b Recognize its own HP IB address c Set all of the bus data handshak
176. T MIX annunciator lights The INSERTION GAIN display shows the gain of the DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency Comments An external controller can be used to control the Noise Figure Meter and system local oscillator The following general conditions must be observed when using an external controller a Connect the system local oscillator and the external controller to the HP IB connector on the Noise Figure Meter b HP IB code H1 must be active c Special Function 46 1 must be active d Special Function 4 0 normal talker and listener must be active Note that thereis no HP IB code for this special function e Special Function 30 0 free run should be active HP IB code is TO 3 143 Operation Comments cont d Related Sections 3 144 HP 8970B Measurement Mode 1 2 contd Special Function 1 2 f The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes g Set up for a calibration with the device under test DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction h Set the system local oscillator to the desired frequency Refer to the local oscil lator s operating manual for the required HP IB
177. The prefix and suffix define the command sequence that will set the frequency or output power Use Special Function 42 to define a new program for other system loca oscillators h Configure the user controlled local oscillator to produce the desired frequency i If a free running non synthesized source is being used as the system local oscillator a Noise Figure Test Set Coarse Tuning Calibration should have been done when the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator was put together The coarse tuning is ONLY required when a free running source is the system local oscillator or repairs have been made to the Noise Figure Test Set For more information on a Noise Figure Test Set Coarse Tuning refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can 3 177 Operation HP 8970B Measurement Mode 1 8 cont d Special Function 1 8 Procedure lower system noise figure and therefore reduce the measurement un cont d certainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer
178. This product and related documentation must be reviewed for familiarization with safety markings and instructions before operation This product is a Safety Class I instrument pro vided with a protective earth terminal BEFORE APPLYING POWER Verify that the product is set to match the avail able line voltage and the correct fuse is installed are removed Energy available at many points may if contacted result in personal injury Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its source of supply For continued protection against fire hazard replace the line fuse s only with 250V fuse s of the same current rating and type for example normal blow time delay etc Do not use repaired fuses or short circuited fuseholders SAFETY EARTH GROUND An uninterruptible safety earth ground must be provided from the main power source to the pro duct input wiring terminals power cord or sup plied power cord set Any interruption of the protective grounding conductor inside or outside the instrument or disconnecting the pro tective earth terminal will cause a poten tial shock hazard that could result in personalinjury Grounding one conduc poe an tor of a two conductor outlet is not suffi cient protection In addition verify that WARNING SAFETY SYMBOLS Instruction manual symbol the product will be marked with this symbol when it is nece
179. This read operation cannot be completed until the new data is ready Itis possible to write an SRQ interrupt routine on the Data Ready SRQ Refer to Enabling the Service Request Condition paragraph 3 30 o Continue to loop through steps m and n A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the frequency that was read from the Noise Figure Meter with the stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal External filtering is necessary for single sideband measurements using Special Func tions 2 1 through 2 3 Calibrate Controller Capability of the Noise Figure Meter Fixed IF or LO Frequency Selection Sideband Selection Special Functions HP 8970B Description Requirements Operation Measurement Mode 1 5 Special Function 1 5 NOTE The HP 8971B Noise Figure Test Set and the system local oscillator are required when making a measurement using Measurement Mode 1 5 Measurement Mode 1 5 provides direct noise figure and gain measurements in the frequency range of 10 to 18000 MHz No external mixer or second local oscillator is needed This measurement mode does not allow for down conversion in the device under test DUT All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make eit
180. URE DISPLAYS AND DISPLAY ITHE ERROR 110 ENTER 708 W1 W2 W3 IGET THE FREQUENCY INSERTION GAIN AND INOISE FIGURE DISPLAYS 120 PRINT The last Noise Figure Meter error was W1 130 OUTPUT 708 FR STOP THE ERROR REPORTING DISPLAY 140 Error_num W1 ISETUP FOR ERROR READBACK i THE NEXT LINES ASK FOR THE TEXT OF THE ERROR NUMBER THAT IS CONTAINED IN THE VARIABLE Wi 150 OUTPUT 708 ER Error_num EN ISETUP ERROR TEXT TO READ 160 ENTER 708 Errmes READ THE TEXT 170 PRINT Errmes 180 END Section VII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 103 Uperation Ar oviup Error Messages and Recovery cont d Related Calibrate Sections Calibration IF Attenuators Calibration Input Gain Selection IF Attenuation Selection Measurement Modes 1 1 through 1 9 Remote Operation HP IB RF Attenuation Selection Service Related Errors Section VIII Special Functions t Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 104 FIM AAAY HP 8970B Description Procedure Operation Fixed Frequency Increment The tuned frequency of the instrument can be changed by using a combination of the FREQ INCR and amp keys The FREQ INCR key is used to set the fixed increment size The t and keys step the fixed frequency up or down by the value of the curre
181. URE display shows the noise figure of the DUT at the displayed frequency Measurement Mode 1 0 is often referred to as an RF measurement The other nine Measurement Modes are often referred to as microwave measurements Calibrate Measurement Modes Special Functions UD eatmnYM HP 8970B Description Requirements Operation Measurement Mode 1 1 Special Function 1 1 Measurement Mode 1 1 provides a means of controlling a system LO to obtain a measurement frequency higher than 1600 MHz This mode allows for frequency con version in the measurement system but not in the device under test DUT Although the signal measured at the Noise Figure Meter INPUT is always in the range of 10 to 1600 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency A typical DUT is an amplifier or transistor An LO and a mixer are required All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements plus the measurement results for each mode can be displayed on an oscilloscope and output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction The following
182. Using the same technique as in step 9 take a voltmeter reading cont d SSeS VE 16 Note the new voltmeter mode reading on the Noise Figure Meter Vdc 17 Decrease the signal generator output power to 5 dB below that set in step 7 18 Using the same technique as in step 9 take a voltmeter reading Vdc 19 Note the new voltmeter mode reading on the Noise Figure Meter Vde 20 Decrease the signal generator output power to 10 dB below that set in step 7 21 Using the same technique as in step 9 take a voltmeter reading Note that the power meter may change ranges for this reading If it does the voltmeter reading taken must be decreased by a factor of 10 Vde 22 Note the new voltmeter mode reading on the Noise Figure Meter Vdc 23 Decrease the signal generator output power to 15 dB below that set in step 7 24 Using the same technique as in step 9 take a voltmeter reading Remember to decrease this reading by a factor of 10 Vde 25 Note the new voltmeter mode reading on the Noise Figure Meter Vdc 26 Decrease the signal generator output power to 20 dB below that set in step 7 27 Using the same technique as in step 9 take a voltmeter reading Note that the power meter may change ranges again If so this voltmeter reading must be decreased by a factor of 100 Vdc 28 Note the new voltmeter mode reading on the Noise Figure Meter Vdc 4 8 HP 8970B Performance Tests PERFORMANCE TESTS NOISE FIGURE RANGE
183. Values 26 Enter the measured attenuator values recorded in Table 4 1 into the Noise Figure Meter NOTE It is not necessary to perform steps 26a through h if you only want to read the IF attenuator values and record them in Table 4 1 4 14 HP 8970B Performance Tests PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure a Key in 93 1 SPECIAL FUNCTION This enables you to enter a RAM cont d address b Key in 65452 and then press ENTER This is the RAM location where you will find the address of the memory protection word The memory protection word must be modified before you can change the IF attenuator values stored in RAM e Key in 93 3 SPECIAL FUNCTION This displays the address of the memory protection word d Record the address of the memory protection word which is ano in the left display of the Noise Figure Meter e Key in 93 1 SPECIAL FUNCTION f Key in the memory protection word address recorded in step d and then press ENTER g Key in 93 3 SPECIAL FUNCTION h Key in 20299 and then press ENTER The value 20299 disables the memory protection and allows you to change the IF attenuator values Turning the instru ment off and then on turns memory protection back on i Key in 93 1 SPECIAL FUNCTION j Key in 65460 and then press ENTER This is the RAM location where you will find the start address of the IF attenuator calibration table k Key in 93 3
184. a noise source ENR of 14 to 16 dB Description Level ratios of 0 1 dB 1 dB 5 dB 10 dB 15 dB and 20 dB are generated The levels are measured on the power meter and linear power ratios are computed The levels are simultaneously measured on the Noise Figure Meter and linear voltage ratios are computed The voltage ratios are squared and then subtracted from the linear power ratios to compute the Y Factor error This error is compared to accuracy limits derived from the 0 1 dB noise figure accuracy specification A 15 dB ENR value is assumed The reading at 20 dB and the reading at 5 dB are used to compute a second 15 dB ratio This ratio is also checked for accuracy NOTES This test is difficult to perform Passing the test requires minimum drift in both the measurement equipment and the Noise Figure Meter The more rapidly the test is performed the more closely the test results will indicate the actual performance of the instrument If the instrument fails by a narrow margin performing the test more quickly will proba bly allow the instrument to pass Since the Noise Figure Meter is highly sensitive to RF signals at its input spurious transmissions or noise can adversely affect performance test results Use short well shielded cables and a minimum of adapters when performing this test Equipment Attenuator 6 dB ccc ccc cece eee ees HP 8491A Opt 006 Attenuator 1 dB Step 0 02000 HP 8494A Opt
185. able System LO on System Inter face Bus LO Frequency for Modes 1 2 1 4 1 7 and 1 9 Go to Lower Left for X Y Recorder Temperature of Losses Loss Compensation Off Loss Compensation On Selects Modification or Inspection of a Byte in RAM or Inspection of a Byte in ROM Cold Manual Measurement Selects Modification or Inspection of a Floating Point Value in RAM or Inspec tion of a Floating Point Value in ROM Hot Manual Measurement System LO Minimum Frequency in MHz Selects Modification or Inspection of a Word in RAM or Inspection of a Word in ROM System LO Maximum Frequency in MHz MHz UNCORRECTED NOISE FIGURE CORRECTED NOISE FIGURE AND GAIN Noise Figure Meter is not system control ler on the System Interface Bus Sets all ENR Values to 15 20 dB and Noise Source ID No to 00000 Enter and Use ENR Noise Figure Lower Limit for Oscilloscope Selects the Noise Pen Number Enter ENR Table Noise Source Catalog Noise Figure Upper Limit for Oscilloscope Noise Figure Display Units F dB F Y dB Y Te K HP IB Code Parameter oem Power Measurements SOURCE Off Uncal SOURCE On Uncal SOURCE Off Cal SOURCE On Cal Output Both Status Bytes Plot Grid and Data Custom LO Power Prefix and Suffix Plot Data Only Perform Noise Figure Test Set Fine Tuning Calibration Plot Grid and Axes Labels Plotter is on the System Interface Bus System LO Power Level Plot Data read on HP IB PRESET System LO CW Prefix
186. active light the SPECIAL FUNCTION key LED on the front panel The Stored in Continuous Memory column indicates whether or not the status of a Special Function can be retained when power is removed from the Noise Figure Meter The Can Be Stored and Recalled column indicates whether or not the status of a Special Function can be stored in an internal storage register for recall at a later time The Special Function 0 0 Conditions column indicates the status of each Special Function that is on off or no change when Special Function 0 0 is selected Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 235 Operation Description cont d Procedure Example indications Related Sections 3 236 HP 8970B Special Functions conta The Preset and HP IB Clear Conditions column indicates the status ofeach Special Function when the front panel PRESET key is pressed or HP IB code PR is sent In addition this column indicates default data values that are set for some Special Functions The Special Function 0 9 Conditions column indicates the status of each Special Function when Special Function 0 9 is selected In addition this column indicates default data values that are set for some Special Functions Special Function 0 9 is the highest level of preset that the Noise Figure Meter has Special Function 0 9 sets up ev
187. al oscillator an external mixer and fixed user controlled local oscillator The Noise Figure Meter can be used to control the system local oscillator Measurement Modes 1 2 and 1 4 and is used to control the Noise Figure Measurement System Measurement Modes 1 7 and 1 9 The Noise Figure Meter controls the system local oscillator as HP 8970B Description cont d Signal Comparison Operation Measurement Modes contd Special Function 1 directed by the system local oscillator program Special Function 41 or 42 Measure ment Modes 1 2 and 1 4 down convert the measurement frequency to 10 to 1600 MHz Measurement Modes 1 7 and 1 9 down convert the measurement frequency to 10 to 18000 MHz Measurement Modes 1 2 and 1 7 have no down conversion in the DUT for example an amplifier or transistor Measurement Modes 1 4 and 1 9 do provide for down conversion in the DUT for example a mixer or receiver Modes 1 2 and 1 7 must be a single sideband measurement Additional information on sideband selection is covered later in this instruction and in the Sideband Selection Detailed Operating Instruction For a summary of the ten Measurement Modes refer to the Measurement Modes Summary table The calibration and measurement setups and procedures are illustrated and specific examples are provided in the Detailed Operating Instructions for Measurement Modes 1 0 through 1 9 In the following discussion signals present at different points
188. al Functions Initializes many Special Functions Initialize Special Functions and 0 9 None Initializes all Special Functions and Sets all Set Defaults Defaults to Factory Set Conditions Measurement Mode Selection 1 0 EO Mode 1 0 10 1600 MHz measurement 1 1 El Mode 1 1 fixed IF variable freq Sys LO 1 2 E2 Mode 1 2 variable IF fixed freq Sys LO SSB 1 3 E3 Mode 1 3 fixed IF variable freq Sys LO mixer is DUT 1 4 E4 Mode 1 4 variable IF fixed freq Sys LO mixer is DUT 1 5 E5 Mode 1 5 10 to 18000 MHz 1 6 E6 Mode 1 6 fixed IF variable frequency User Controlled LO 1 7 E7 Mode 1 7 variable IF fixed frequency User Controlled LO SSB 1 8 E8 Mode 1 8 fixed IF variable frequency User Controlled LO mixer is DUT 1 9 E9 Mode 1 9 variable IF fixed frequency User Controlled LO mixer is DUT Sideband Frequency Offset 2 0 BO Double Sideband no offset 2 1 Bi Lower Single Sideband F sonal lt F Lo 2 2 B2 Upper Single Sideband F yigna gt Fio 2 3 B3 Signal Up Conversion Far Fyeignal Fo Enter IF and LO Frequencies 3 0 IF IF for Modes 1 1 1 8 1 6 and 1 8 3 1 LF LO for Modes 1 2 1 4 1 7 and 1 9 3 2 UL Displays User Controlled LO Frequency in Modes 1 6 through 1 9 Control Function Selection 4 0 none Norma Talker and Listener 4 2 none Talk Only ENR Thot Settings and 5 0 SO Use ENR Table ENR Table Selection 5 1 1 Use Spot ENR 2 SE Display Current ENR in dB 5 3 NE Enter and Use Spot ENR 5 4 TH Ente
189. alization or requirements for a check are described at its beginning The test setup is the same for all of the checks Connect the Noise Figure Meter to the bus controller via the HP IB interface Do not connect any equipment other than the noise source to the Noise Figure Meter s INPUT HP IB Controller 0c00 HP 85B 82936A ROM Drawer 00085 15005 Advanced Programming ROM or HP 9000 Series 200 300 BASIC 2 0 ROM based system HP IB Interface 0 cc cece eee es HP 82937A HP 85B only Noise Source cc cece ee eee eens HP 346B Option 001 3 21 Operation i gt HP 8970B OPERATOR S CHECKS HP IB Functional Checks cont d Address Recognition Note Operator s Response Operator s Response This check determines if the Noise Figure Meter recognizes when it is being addressed and when it is not This check assumes only that the Noise Figure Meter can properly handshake on the bus Before beginning this check set the Noise Figure Meter s LINE switch to ON press PRESET 45 0 SPECIAL FUNCTION and 4 0 SPECIAL FUNCTION HP 85B HP 9000 Series 200 300 Description BASIC BASIC Set the Remote Enable REN bus control LOCAL 7 LOCAL 7 line false Send the Noise Figure Meter s listen address OUTPUT 708 OUTPUT 708 Check that the Noise Figure Meter s REMOTE annunciator is off and thatits LISTEN annunciator is on Unaddress the Noise Figure Meter OUTPUT 715 OUTPUT 715
190. am stored in the Noise Figure Meter s temporary memory runs whenever a frequency value is entered from the front panel of the Noise Figure Meter and the system LO is required The program is also triggered each time an auxiliary command is changed when a system LO is connected When the program is running the following sequence occurs a A frequency command is given b The power level is set c The auxiliary commands are given d The Noise Figure Meter waits for the programmed settling time and then makes a measurement This sequence is repeated until all of the frequencies required by the measurement setup have been sent and the measurement results obtained Each time the frequency is changed the Noise Figure Meter issues an HP IB command string The Noise Figure Meter sends the following HP IB commands to the system LO in the order indicated a REN and ATN are both set true b the LO s listen address is sent c ATN is released that is set false d the frequency command is sent e the power command is sent f the auxiliary commands are sent g carriage return CR and line feed LF are sent HP 89708 HP 8970B Procedure cont d Examples Operation Programming The System LO conrad Special Function 42 Because the frequency command precedes the auxiliary commands a Preset or Initialize command cannot be used in the auxiliary commands These type of commands will prevent the system LO from tuning
191. amplifier refer to the Preamplifier Selec tion Detailed Operating Instruction a Verify that the minimum requirements specified under Requirements are satisfied b Press PRESET c Press 1 7 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 7 d Set frequency parameters including the fixed frequency for the user controlled local oscillator Special Function 3 1 e Select sideband operation desired Special Functions 2 1 through 2 3 and 17 Special Function 2 1 is the default f Select appropriate smoothing Special Function 13 g Enter the noise source ENR table h Set the user controlled local oscillator to the frequency specified by Special Func tion 3 1 i Perform a Noise Figure Test Set Fine Tuning Calibration For more information refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction j Calibrate the Noise Figure Measurement System in Mode 1 7 this is only required for a CORRECTED NOISE FIGURE AND GAIN measurement External filtering is required during both calibration and the measurement If a preamplifier is required for the measurement the preamplifier must be used in the calibration k Insert DUT and make a noise figure or noise figure and gain measurement Example NOTE The following example assumes that the Noise Figure Meter is the controller An external controller can be used to control the Noise Figure Measurement System and the user controll
192. and Suffix Display and Enter the Address of the Pass Through Device on the System Interface Bus Normal Display to return from displaying manual measurement results Display Manual Measurement Results Sequence Functions Automatic Clear Manual Set Service Request Disable SRQ Capability Enable Data Ready to Cause SRQ Enable Cal Complete to Cause SRQ Enable HP IB Code Error to Cause SRQ Enable SRQ on the System Interface Bus to Cause SRQ Enable Noise Figure Meter received control on the System Interface Bus to Cause SRQ Enable Instrument Error to cause SRQ Enable Extended Status Byte to Cause SRQ RECALL Set Extended Status Byte Mask RF Attenuator Hold Set Status Byte Mask Reset Status Bytes RF Attenuation Selection Auto 20 dB 10 dB 3 49 Operation HP 8970B cz gt Table 3 8 Noise Figure Meter HP IB Code to Parameter Summary 4 of 4 HP IB Code HP iB Code Parameter Parameter a oo mw O i gt 3 50 RF Attenuation Selection cont d 0dB 10 dB 20 dB 30 dB Noise Figure Meter does a Serial Poll on the System Interface Bus Noise Figure Meter is System Controller on the System Interface Bus Displays Current Software Date Display Current ENR Display IF Attenuator Setting Enter Noise Source Identifier SPECIAL FUNCTION SEQ Display RF Attenuator Setting STEP SIZE STORE Use ENR Table Use Spot ENR Noise Figure Measurement System Internal IF Selection Display and Enter Internal IF for SSB2 Disp
193. and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes f Set the user controlled local oscillator to the appropriate frequency Refer to the local oscillator s operating manual for the required HP IB codes Allow sufficient time for the output of the local oscillator to stabilize g Perform a Noise Figure Test Set Fine Tuning Calibration and a Noise Figure Measurement System Calibration with the DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction and the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction A Noise Figure Test Set Fine Tuning Calibration may need to be done separately from the measurement system calibration The separate fine tuning calibration is needed ifa mixer is being used out in front of the Noise Figure Measurement System and a preamplifier is not being used An Excess Noise Ratio ENR of 13 dB or greater is needed at the input to the Noise Figure Test Set during the fine tuning calibration h Send the command RM 2EN RS CA Wait for a serial poll to return a non zero value indicating calibration is complete i Insert the DUT into the measurement system j Special Function 30 1 trigger hold must be active HP IB code is T1 HP RQ70R HP 8970B Comments cont d Related Sections Operation Measurement Mode 1 7 conta Special Function 1 7 k Set the Noise Figure Meter s SINGLE sweep on HP IB co
194. and the displayed data can be read over the HP IB as many times as required Trigger hold is useful when the measure ment setup must be reconfigured before making the next measurement Special Function 30 2 triggers one measurement and then returns to the previously selected trigger mode Normally this trigger execute command is used in conjunction with the trigger hold mode Once the measurement is complete the results are dis played and are available via the HP IB The measurement results are also output to an oscilloscope or recorder if one is connected to the rear panel X Y and Z connectors If a smoothing factor other than one has been selected the Noise Figure Meter makes the number of measurements required by the selected smoothing factor before the smoothed measurement is displayed or available via the HP IB To select a specific triggering mode key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Specia Function Program Code en ome ED 30 0 TO or 30 0SP 30 1 Tlor30 1SP 30 2 T2 or 30 2SP Lights Special Function Key tinuous Memory Gan be Stored Special Function 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions and Recalled Stored in Con Free Run Hold Execute Table categories are explained in the Special Functions Detailed Operating Instruction To select trigger hold and
195. andwidth The system local oscillator is controlled by the existing system local oscillator programs in the Noise Figure Meter The system local oscillator programs can be modified to sweep the system local oscillator up to 99999 MHz In Measurement Modes 1 6 and 1 8 the user controlled local oscillator can be swept over any range necessary needed for a measurement The user controlled local oscillator is controlled by the user and not by the Noise Figure Meter The frequency that the user controlled local oscillator needs to be set to can be displayed using Special Function 3 2 In 3 127 Operation nee Acan Mode Measurement Frequencies System LO Required Measurement Modes Summary User Controlled LO Required IF into NF Meter Modes 1 1 1 4 or IF into NF Test Set Modes 1 6 1 9 HF sy Ub Sidebsnd Selection Microwave Amplifier Microwave Amplifier Mixer Receiver Mixer Receiver RF or Microwave Amplifier Millimeter Wave Amplifier Miilimeter Wave Amplifier Mixer Receiver Mixer Receiver Jm ae IF 10 1600 MHz iF 10 1600 gt 18000 MHz and iF 1601 18000 MHz gt 18000 MHz and iF gt 1600 MH2 iF 1601 18000 MHz 1 Double sideband Special Function 2 0 Lower single sideband measurement frequency lt LO frequency Upper single sideband measurement frequency gt LO frequency Yes Variabie frequency Yes Fixed frequency set with Special
196. anual The prefix and suffix are used to format the command sequence that sets the power level The prefix suffix count character for the prefix and count character for the suffix can be a maximum of twenty four 24 characters The count character indicates the number of ASCII characters in the prefix or suffix The prefix and suffix should be entered using the following format CPPPPCSSSS C equals the decimal count character P equals the prefix ASCII characters S equals the suffix ASCII characters Use the front panel to enter the ASCII characters using their decimal equivalents Since the count characters are in decimal they are entered as they are Press ENTER each time a decimal number is keyed in h Press 42 5 SPECIAL FUNCTION Enter the power level 0 to 30 dBm using the front panel keys Press ENTER i Press 42 7 SPECIAL FUNCTION Enter the count character for the prefix the prefix characters the count character for the suffix and the suffix characters for the output frequency The prefix and suffix can be found in the local oscillator s operating manual The prefix and suffix are used to format the command sequence that sets the output frequency The prefix suffix count character for the prefix and count character for the suffix can be a maximum of twenty four 24 characters The count characters indicate the number of ASCII characters in the prefix or suffix The prefix and suffix should be entered using the following for
197. art EN FB Stop EN Start and stop frequencies 100 OUTPUT Nfim SS Step EN 1Step Size 110 INPUT MAKE SURE THE NOISE FIGURE METER IS SETUP FOR A CALIBRATION AND PRESS ENTER A 120 130 140 INOW BEGIN TAKING DATA FROM THE CALIBRATION 150 160 OUTPUT Nfm RM 2 EN Setup calibration complete SRQ 170 OUTPUT Nim RS iReset Noise Figure Meter Status Byte 180 OUTPUT Nim CA Start the calibration 190 Loop Loop to do all measurements 200 HN MEASUREMENT MODES 1 6 THROUGH 1 8 210 APPROPRIATE COMMANDS TO CONTROL THE USER 220 ICONTROLLED LOCAL OSCILLATOR SHOULD BE ADDED HERE 230 OUTPUT Nim T2 Trigger a measurement 240 ENTER Nim Freq GkB Tem Get the calibration frequency gain reference and isecond stage temperature 250 PRINT FREQ GkB Tem Freq GkB Tem 260 S SPOLL N m IGet Noise Figure Meter Status Byte 270 IF BIT S 1 0 THEN GOTO Loop IContinue until done 280 290 PRINT DONE 300 310 END If any of the 60 or 70 series of Special Functions except 60 0 and 70 0 are active the calibration sequence does not override them Therefore to calibrate on onerange only use any of these Special Functions except 60 0 or 70 0 If any of these Special Functions are inadvertently left active the calibration sequence may not cover the expected gain range Any loss compensation entered by Special Function 34 is ignored during the calibration sequence Calibration
198. as if the entry was never received The last volatile or nonvolatile error generated can be displayed using Special Function 99 1 HP IB code ER The error may already be resolved or can be active When the error is requested over HP IB the error will be displayed using the error code or can be displayed in English Using the English display an error code does not have to be interpreted The Comments section at the end of this instruction contains a program for displaying the error in English The HP IB output format for errors is 90DDDE 06CRLF Fixed Data Line Feed Error Code Carriage Return Fixed Exponent For example Error 10 is output to the HP IB as 90010E 06CRLF This format differs from normal data outputs since normal data outputs will never exceed 1 x 10 Once an error has been input to the computing controller the error code is simply derived by subtracting 9 x 10 from the input number and then dividing the result by 1 000 000 3 93 Operation HP IB Output Format aizl gt cont d Error Displays 3 94 HP 8970B Error Messages and Recovery contd Specia Codes Over HP IB When a read of the Noise Figure Meter is attempted during the following operations ENR editing ENR catalog Noise Figure Test Set Coarse or Fine Tuning Calibration the Noise Figure Meter will output special HP IB codes for the NOISE FIGURE window The special HP IB codes are given below ENR Editing 80 TNNE 06 Fixed bata
199. auto pass control capabilities control is not automatically passed between the Noise Figure Meter and another controller 1 Special Function 49 1 enables auto pass control For instruments with auto pass control capabilities control is automatically passed between the Noise Figure Meter and another controller 3 263 Operation Description cont d Procedure 3 264 HP 8970B System Interface Bus Control contd Special Functions 45 through 49 m Special Function 49 2 tells the Noise Figure Meter to release active control of the System Interface Bus This special function is useful if control of the System Interface Bus is to be shared Special Function 49 2 should be used before another controller is told to take control n Special Function 49 3 telis the Noise Figure Meter to take active control of the System Interface Bus Special Function 49 3 is only useful if there are more than two controllers on the System Interface Bus and control of the System Interface Bus is to shared This special function should be used after all other controllers have been told to release control of the System Interface Bus o Special Function 49 4 tells the Noise Figure Meter to do a serial poll on the System Interface Bus The request is usually given by an external computer over the Hewlett Packard Interface Bus using the HP IB code SB For a serial poll program example refer to the Comments section at the end of this instruction p
200. be Stored and Recalled Special Function 0 8 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions iTable categories are explained in the Special Function Detailed Operating Instruction 3 81 Operation Example Program Codes z gt Related Sections 3 82 HP 8970B Display Control contd Special Function 16 To blank the left frequency display LOCAL ann COG e aan FUNCTION amn keystrokes G Ta 2 Ba lt program codes For HP IB codes refer to the Procedure above Measurement Modes 1 1 through 1 9 HP 8970B Description Procedure Operation Display Resolution Includes Special Function 12 The Noise Figure Meter can vary the resolution of the INSERTION GAIN and NOISE FIGURE displays The table below shows the maximum resolution to the right of the decimal point allowed by Special Function 12 i 12 0SP Maximum 12 18P Less Resolution 12 2SP Less Resolution Display Resolution on NOISE FIGURE on GAIN NOISE FIGURE FdB F YdB Y Te K INSERTION GAIN dB To select the desired display resolution key in the correspo nding Special Function code and then press the SPECIAL FUNCTION key Special Function Program Code enn e ED Maximum resolution for both INSER TION GAIN and NOISE FIGURE displays Lights Special Function Key Stored in Con tinuous Memory Can be Stored and Recalled Special Function 0 0 Condi
201. ble Auto Sweep Abort See Error E102 Last Error 99 1 Recalls Last Error Issued Software Date 99 9 Displays Current Software Date Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code Table 3 10 Front Pane Keys to HP IB Code Summary AUTO PRESET CALIBRATE RECALL DECREASE SEQ ENR SINGLE ENTER SPECIAL FUNCTION FREQ INCR START FREQ v STEP SIZE _ 3 STOP FREQ FREQUENCY STORE GRAPHIC SCALE Sweep and Calibrate Off must be used to GAIN MAX turn these functions off over the HP IB GAIN MIN NOISE MAX NOISE MIN INCREASE NOISE FIGURE UNCORRECTED NOISE FIGURE AND GAIN CORRECTED 3 57 Operation 3 58 HP 8970B Table 3 11 Commonly Used Code Conversions Hexa Binary Decimal decimal 25 ee Noa w SERE BREI SEBS 00 010 171 00 011 000 00 041 091 00 011 010 00 074 011 00 011 100 00 011 101 00 011 110 00 011 111 00 100 000 00 100 001 100 010 j ZSZgZg 883 S888 S888 SS 00 140 111 06 111 000 00 111 001 00 171 010 00 111 031 00 114 100 00 111 101 00 111 110 00 111 111 wm NONA WR w Rete Hexa Binary Decimal decimal 01 000 000 01 000 004 01 000 010 01 000 011 01 000 100 01 000 101 01 000 110 01 000 114 01 001 000 G1 001 001 61 001 010 61 001 011 04 001 100 01 00 101 01 001 110 G1 007 171 01 070 000 61 0146 001 01 010 010 01010 011 01 010 16
202. ble number with entry number Figure 3 2 Display and Remote Features HP 8970B GRAPHIC BOREK y we DAR GRAPHIC SCALE The GRAPHIC SCALE keys are used to select the vertical scaling for an oscilloscope display or a plotter The keys select the maximum and minimum limits for the display or plot These keys perform the same functions as Special Func tions 8 1 thorugh 8 4 2 GAIN MAX Key Used to display and enter the oscillo scope or plotter maximum vertical limit for insertion gain When pressed the current GAIN MAX value appears in the left display The allowable range of values for GAIN MAX is 9999 dB to 99999 dB This key performs the same function as Special Function 8 4 3 NGISE MAX Key Used to display and enter the oscil loscope or plotter maximum vertical limit for noise figure When pressed the current NOISE MAX value appears in the left display The allowable range of Operation parse TE i A LAK r values for NOISE MAX is 9999 dB to 99999 dB This key performs the same function as Special Function 8 2 QO GAIN MIN Key Used to display and enter the oscillo scope or plotter minimum vertical limit for insertion gain When pressed the current GAIN MIN value appears in the left display The allowable range of values for GAIN MIN is 9999 dB to 99999 dB This key performs the same function as Special Function 8 3 NOISE MIN Key Used to display and enter the oscil loscope or plotter mini
203. bled when it is not desired If Auto Pass Control is not desired select Special Function 49 0 to disable Auto Pass Control If Auto Pass Control Special Function 49 1 should be active verify that the other controller is connected to the SYSTEM INTERFACE BUS connector and not to the HEWLETT PACKARD INTERFACE BUS connector Also verify that the address of the control ler is the same as the address specified by Special Function 40 5 Error code E48 is generated when the Noise Figure Meter has detected the existence of another controller on the System Interface Bus the Noise Figure Meter was told Special Function 48 0 that it would be the controller Verify that a controller is connected to the HEWLETT PACKARD INTERFACE BUS connector and not to the SYSTEM INTERFACE BUS connector HP 8970B Comments contd Uperation Error Messages and Recovery contd In systems where there are multiple controllers on the System Interface Bus that are sharing resources such as a local oscillator or a plotter only one of the controllers should be enabled to be the system controller or active controller at any given time Verify that the other controllers are not set to be the system controller at turn on Ifthe Noise Figure Meter has been told to be the system controller it will display Ctrl on in the right display after power on If the Noise Figure Meter has been told not to be the system controller the message Ctrl OFF will appear i
204. by sending a different address Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators are off Remote and Local Messages and the LOCAL Key Note Operator s Response Operator s Response This check determines if the Noise Figure Meter properly switches from local to remote control from remote to local control and if the LOCAL key returns the instrument to local control This check assumes that the Noise Figure Meter is able to both hand shake and recognize its own address Before beginning this check press the Noise Figure Meter s PRESET key Then press 4 0 SPECIAL FUNCTION HP 858 HP 9000 Series 200 300 BASIC BASIC Description Send the Remote message by setting REMOTE 708 REMOTE 708 Remote Enable REN true and addressing the Noise Figure Meter to listen Check that the Noise Figure Meter s REMOTE and LISTEN annunciators are on Send the Local message to the Noise Figure LOCAL 708 LOCAL 708 Meter Check that the Noise Figure Meter s REMOTE annunciator is off but its LISTEN annunciator is on Send the Remote message to the Noise REMOTE 708 REMOTE 708 Figure Meter 3 22 HP 8970B Operation gt OPERATOR S CHECKS HP IB Functional Checks cont d Remote and Local Messages and the LOCAL Key cont d Operator s Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators are on Response Press the LOCAL key on the Noise Figure Meter Check that
205. c operation or properly set manual conditions Bandwidth approximately 4 MHz Audible Noise Level lt 5 5 bels at 1 metre Sensitivity no external gain required 100 dBm able to measure its own noise figure Measurement Speed about 6 to 9 measurements per second with minimum smoothing Sweep Speed at Minimum Smoothing 10 to 1600 MHz 140 ms per frequency point Maximum Safe input Level 20 Vdc 20 dBm peak or average at RF FUNCTIONAL PROPERTIES Noise Figure Display Units noise figure in dB or as a ratio or uncorrected Y Factor in dB or as a ratio or effective input noise temperature in kelvins Displayed Measurement Frequency Range 10 to 99999 MHz Number of Calibration Points in One Sweep 181 System LO Control frequency contro over the System Interface Bus from 10 to 99999 MHz Noise Figure Display Jitter lt 0 01 dB with appropriate smoothing Cold Noise Source Data Range 0 to 9999K Hot Noise Source Data Range stored table ENR from 7 to 50 dB spot frequency from 0 to 14824K Storage Capacity of Hot Naise Source Tables Four stored ENR tables with 35 frequencies each plus one working ENR table Smoothing exponential averaging of gain and noise figure before display according to D P F 1 M F where D is the display result prior to conversion to logarithmic form P is the previous result M is the latest measurement and F is the averaging factor 1 2 4 8 16 32 64 128 256 or 512 Ari
206. calibrated The calibration will be done for each input gain setting at the frequencies set by START FREQ STOP FREQ and STEP SIZE During calibration the following indications can be seen on the Noise Figure Meter Noise Figure Test Set and System Local Oscillator Noise Figure Meter a The frequency point being calibrated will be shown in the left display b The noise figure of the frequency point is shown in the NOISE FIGURE display c The INSERTION GAIN display is blank Noise Figure Test Set a The REMOTE annunciator is on b The LISTEN annunciator will flash c The annunciators for SSB1 SSB2 and SSB3 will step from SSB1 to SSB2 to SSB3 3 30 HP 8970B Operation OPERATOR S CHECKS Noise Figure Measurement System Check cont d Procedure cont d 14 15 16 17 18 19 20 21 22 23 24 25 26 System Loca Oscillator a The REMOTE annunciator is on b The LISTEN annunciator will flash c The FREQUENCY display will be changing When calibration is complete press 17 1 SPECIAL FUNCTION The annunciator for band DSB double sideband will light up on the Noise Figure Test Set On the Noise Figure Meter change the stop frequency by pressing SWEEP STOP FREQ keying in 3000 and pressing ENTER Observe the NOISE FIGURE display on the Noise Figure Meter The noise figure displayed should be between 8 and 12 dB If the system performed as indicated in steps 13 throu
207. calibration is complete h Insert the DUT into the measurement system i Special Function 30 1 trigger hold must be active HP IB code is T1 j Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 k Set the user controlled local oscillator to the desired frequency depending on the sideband selection If double sideband was selected the oscillator should be set to the measurement frequency If lower sideband was selected the oscillator should be set to the measurement frequency plus the IF If upper sideband was selected the oscillator should be set to the measurement frequency minus the IF If sum upconversion Special Function 2 3 was selected set the oscillator to the IF minus the measurement frequency Refer to the user controlled local oscillator s operating manual for the required HP IB codes Allow sufficient time for the output of the user controlled local oscillator to stabilize 1 Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep m A method must be determined when to step to a new frequency after reading the noise figure results This read operation cannot be completed until the new data is ready It is possible to write an SRQ interrupt routine on the Data Ready Status Bit Refer to Enabling the Service Request Condition paragraph 3 30 n Continue to loop through steps k 1
208. cial Function 61 0 ae Soecial Attenuator or Amplifier unction 10 d8 20 dB 10 d8 10 dB 20 0 1 0 0 10 0 10 20 30 If any of the 60 or 70 series of Special Functions except 60 0 and 70 0 are active the calibration sequence does not override them Therefore to calibrate on one range only use any of these Special Functions except 60 0 or 70 0 It is also true that if any of these Special Functions are inadvertently active the calibration sequence will not cover the expected gain range Calibrate IF Attenuation Selection Manual Measurements Special Functions Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual 3 223 Operation HP 8970B Sequence includes Special Function 35 Description The sequence feature allows the user to predetermine the recall order of the storage registers Manual sequence recall of registers one at a time or automatic sequence continuous recall of registers can be selected Nine digits are used in a sequence Any combination of registers 1 through 9 is allowed Zeros used within a sequence are ignored Procedure To set the sequence that is the recall order key in 35 2 SPECIAL FUNCTION The 3 224 register to be recalled at each step of the sequence is displayed in turn in the left display If a change is desired enter the new register number and press ENTER If nochangeis desired press E
209. cial Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 3 248 HP 8970B Operation Table 3 14 Special Function Summary 11 of 15 gt B ffi s T Ll kpi 4 7 gs SE ERES 55 25 Special Function Program sif sees 88 TS inti aces eo BS st References and Code Description zg S2 2t go SE ss Comiants ese G6 Line6 Status N N N Function j Catalog Line 7 Status NIN N contd Line 8 Status NIN N RF Attenua NIN N RF Attenuation tion Selection YININ Selection R2 YIN N R3 YININ R4 Yj NIN i R5 YININ R6 Y NIN Display RF SR Display RF Attenuators IN ININ RF Attenuation Attenuator Selection Settings RF Attenuator 62 0 RH RF Attenuators areheld Y N N Off Off Off RFAttenua Hold in the configuration that tion Selection exists when Special Func tion 62 0 is activated Individual RF ZO Select RF through Path Y N N Off Off Off RF Attenuation Attenuator Selection Selection Zi tua 10dB Pad Number Y I N N Off Off Off Refer to Section VIII Service Z2 Select 20 dB Input Y ININ Off Off Off Amplifier Z4 Select 10 dB Pad Number Y N N Of Off Off 2 Z5 Select 10 dB Pad Number Y N N Off Off Off 3 Most Rppo Functions can be programmed using either the code number followed by SP or the HP IB Code N No
210. cillator 3 267 Operation Example cont d 3 268 HP 8970B System Interface Bus Control conta Special Functions 45 through 49 To get out of Pass Through Mode simply address the Noise Figure Meter or press the LOCAL key Once the Noise Figure Meter is addressed it is out of Pass Through Mode until the next time an output is done to the pass through address NOTE Error 46 E46 is generated if the instrument on the SIB is not found or the address of the instrument ts incorrect If the Noise Figure Meter is addressed all the instruments on the SIB are re initialized to the state they were in before Pass Through Mode was enabled To avoid the instruments from being re initialized Special Function 45 2 disable Noise Figure Test Set and Special Function 46 1 disable local oscillator can be used before Pass Through Mode is enabled PTdEN When finished with Pass Through Mode the appro priate special functions for the Noise Figure Test Set and local oscillator should be enabled Passing Control On The System Interface Bus The Noise Figure Meter has the capability of passing control to another instrument on the System Interface Bus An external computer on the Hewlett Packard Interface Bus determines which instrument will have control instrument Configuration The following minimum requirements are necessary for the Noise Figure Meter to be able to pass control on the System Interface Bus NOTE The follo
211. cording to previously programmed setup It responds equally to bus command GET and program code T2 Trigger Execute a Data message Clear Yes The Noise Figure Meter is set to the same condi DCL DC1 tions established by pressing PRESET Refer to SDC Table 3 6 Remote Yes Remote mode is enabled when the REN bus con REN RLI trol line is true However remote mode is not entered until the first time the Noise Figure Meter is addressed to listen The front panel REMOTE annunciator lights when the instrument is actu ally in the remote mode When entering the remote mode no instrument settings or functions are changed but all front panel keys except LOCAL are disabled Local The Noise Figure Meter returns to local mode front panel control It responds equally to the GTL bus command and the front panel LOCAL key When entering the local mode no instrument settings or functions are changed Local Disables all front panel keys including LOCAL LLO RL1 Lockout Only the controller can return the Noise Figure Meter to local front panel control The Noise Figure Meter returns to local front REN R panel control and local lockout is cleared when the REN bus control line goes false When enter ing local mode no instrument settings or func tions are changed The Noise Figure Meter cannot pass or take control of HP IB Control Take Control Commands Control lines and Interface Functions a
212. ction Ill rene se OPERATION i l 1 2 Introduction oes os ces etecaee ada ue ARN 3 1 12 Operating Characteristics 00005 3 1 12 Local Operation sists gies ces ecko needa s amp l 3 Remote Operation osnesasssoussrsesrssee 3 1 13 Operator s Checks nesessesnessesssreere 3 2 Operator s Maintenance cceeeeeeeee 3 2 13 General Operating Instructions 3 2 13 POI es sce Sareea Daiie he seb vere TS E 3 2 2 23 Keystroke Sequences ecccceeccesace 3 3 2 18 Operator s Checks 23404 ss scnawetaaiwse vegans 3 15 183 Basic Functional Checks 00 00 3 15 23 HP IB Functional Checks 0005 3 21 13 Noise Figure Measurement System PESGI e Cheek serrr a a a Mote ee toy 3 28 E Remote Operation c0cc cece eee esceaeus 3 33 td HP IB Compatibility 0 00eaee 3 33 a th Remote Mode ciserrreeraerre rrada ia tee Ta 3 33 Focal M d odrea rras uros ETNE EREE 3 33 14 Addressing ai Ayana ise a heres Waele gta 3 33 ee 7 Data Mesbapes inciting erin Swhesunaescdsvads 3 34 Receiving the Data Message 002 3 34 o 14 Sending the Data Message 00 3 37 l4 Receiving the Clear Message 005 3 38 oo L4 Receiving the Trigger Message 3 40 eine Receiving the Remote Message 3 40 ee Receiving the Local Message 4 3 40 Receiving the Local Lockout Message
213. cy Once the HP IB command for calibration CA is issued the T2 mnemonic for trigger execute must be used The Noise Figure Meter will ignore the alternate HP IB code of 30 2SP Refer to the Trigger Selection Detailed Operating Instruction for additional triggering information It is assumed that the triggered calibration is being performed as a part of the procedure in the Comments section of the Detailed Operating Instructions for Measurement Modes 1 0 through 1 9 All Measurement Modes require a triggered calibration sequence Therefore the preliminary steps such as selecting Special Function 4 0 will have already been performed The following general conditions must be observed when using an external controller to perform a triggered calibration a Remove the device under test DUT from the measurement system b Set the Noise Figure Meter to trigger hold T1 mode c Set the Noise Figure Meter s calibrate function on HP IB code is CA d Set the LO to the appropriate frequency Refer to the LO s operating manual for the required HP IB codes Allow sufficient settling time for the output of the LO to stabilize e Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for it will be ignored f Amethod must be determined when to step to a new frequency and read the noise figure results This read operation cannot be completed until the new data is ready Itis possible to write an SRQ interrupt ro
214. cy The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used to control the Noise Figure Measurement System and the user controlled local oscillator The following genera conditions must be observed when using an external controller a The external controller and the user controlled local oscillator must be connected to the Noise Figure Meter s HP IB connector b HP IB code H1 must be active c Special Function 4 0 normal talker and listener must be active Note that there is no HP IB code for this special function 3 181 Operation Comments cont d Related Sections 3 182 Hr 89 06 Measurement Mode 1 8 cont d Special Function 1 8 d Special Function 30 0 free run should be active HP IB code is T0 e The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes f Perform a Noise Figure Test Set Fine Tuning Calibration and a Noise Figure Measurement System Calibration with the DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction and the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction g Send the command RM 2EN RS CA Wait for a serial poll to return a non zero value indicating
215. cy range for entries is from 10 MHz to 99999 MHz The valid power range for the ENR entries is from 6 to 50 dB During a measurement the Noise Figure Meter searches the ENR table until the measurement frequency is found If the measurement frequency is between ENR table entries the Noise Figure Meter will interpolate the ENR data If the measurement frequency is higher than the highest table entry the Noise Figure Meter will use the ENR value of the highest table entry If the measurement frequency is lower than the lowest table entry the Noise Figure Meter will use the ENR value of the lowest table entry When power is initially applied to the Noise Figure Meter the ENR table contains the default value of 15 20 dB at ali frequency points After an ENR table is entered for a specific noise source this information is retained in the continuous memory and need not be re entered each time power is turned off and on This discussion will cover the following areas 9 Entering a new ENR Excess Noise Ratio table e Editing an ENR table Viewing information on stored ENR tables NOTE The Noise Figure Meter has five tables Tables 0 4 that are used for ENR data Tables 1 4 are used to store ENR data Table 0 contains the ENR data that is currently being used Information in Table 0 can be stored to Tables 1 4 Information in Tables 1 4 can be recalled to Table 0 If ENR data has not been previously entered into any of the tables as with a n
216. d measurements in Meas urement Modes 1 5 to 1 9 Enables interpolated measurements in Meas urement Modes 1 5 to 1 9 On Calibration 39 1 EG HP IB and SIB 40 0 none Display and Enter Noise N Y N INC NC 8 HP IB and SIB Addresses Figure Meter Address Addresses 40 1 EA Display and Enter Sys Ni Y N NC NC 19 LO Address 40 2 HT DisplayandEnterNoise N Y N iNC NC 10 Figure Test Set Address 40 3 HP Display and Enter Ni Y Y NiINC NC 5 Plotter Address 40 4 HS Display and Enter Sys Ni Y iN NCi NC 8 tem Interface Bus Address 40 5 HC Display and Enter the Ni Yi N INC NC 16 Pass Control Address 40 6 PT Display and Enter the Ni YIN INC O 0 Address of the Pass Through Device on the System Interface Bus 40 7 VP Display the Pass NININ NC NC NC Through Address of the Noise Figure Meter System LO HP 8350B Sweep Programs Programs Oscillator Available to Control the HP 8671B 8672A Syn Signal Generator System LO HP 8673B C Syn Signal Generator HP 8340B 8341B Sweep Oscillator Custom Local Oscillator Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable Also Pass Through Mode is disabled 3 245 Uperation HP 8970B Table 3 14 Special Function Summary 8 of 15 Stored in Con References and
217. d noise figure exceeds 32 dB This display is output to the HP IB as E99 using the HP IB output format 90099E 06CRLF The display above indicates that the data is not ready This display is output to the HP IB as a special reserved number 90000E 06CRLF The table below describes all operating and entry errors The error code message and the action typically required to remove the error causing condition are given Addi tional information pertaining to particular errors is also given Error Volatile V or m 4 Aetlen t Code Nonvelatile NV Message Recommended Action Comments General Remedy Press PRESET and check that input signal is within the specified amplitude and frequency range A D conver sion failed Refer to Service Related Errors in Section VIII Service A D converter overflow Set IF and RF attenuators to autorange Special Functions 70 0 and 60 0 If error persists refer to Service Related Errors in Section VHI Service Also check for proper operation of the Noise Source Set RF attenuators to autorange Special Function 60 0 If error persists refer to Service Related Errors in Section VIII Service Input overflow IF attenuator calibration failed Proper IF or RF attenua tors cannot be selected Refer to the Calibration IF Attenuators Detailed Operating Instruction If error persists refer to Service Related Errors i
218. d suffix are set much like Special Function 42 1 sets the frequency prefix and suffix Once Special Function 42 6 is set up Special Function 42 5 is used to set the power level With Special Function 42 6 the prefix and suffix can total as many as twenty four 24 characters The twenty four characters include the count character for the prefix the prefix characters the count character for the suffix and the characters for the suffix The count characters indicate the number of characters that are in the prefix or suffix g Special Function 42 7 is used only when the custom local oscillator Special Function 41 5 program has been selected Special Function 42 7 is used to properly format the command sequence that will set the output frequency Special Function 42 7 is similar to Special Function 42 1 prefix and suffix With Special Function 42 1 the prefix and suffix used to format the output frequency is limited to four 4 ASCII characters With Special Function 42 7 the prefix and suffix can total as many as twenty four 24 characters The twenty four characters include the count character for the prefix the prefix characters the count character for the suffix and the characters for the suffix The count characters indicate the number of characters in the prefix or suffix The listings for the five predefined programs are shown below Each listing shows the data that is stored in permanent memory Also shown are the system LO Commands Sp
219. d the second stage temperature are given below Pmoy Picota GkB Thos z Tieota Second Troi Teoa YH Stage S ee Temperature Y 1 P ot Y P cold P hot is the power in joules second for a hot noise source on measurement during calibration P cold is the power in joules second for a cold noise source off measurement during calibration T hot is the temperature in Kelvin for a hot measurement from the ENR Excess Noise Ratio tables T cold is the temperature in Kelvin for a cold measurement set with Special Function 6 0 The same general conditions steps a through g as described earlier also apply when performing a triggered calibration and outputting the data to the controller The exception is that the command H2 must be used The following is an example of a program that will perform a triggered calibration and output the calibration data in Measurement Modes 1 0 or 1 5 NOTE This program was written in BASIC language 3 0 using the HP 9000 Series 200 Model 236 computer 3 63 Operation Comments cont d Related Sections 3 64 HP 8970B Calibrate cont a Includes Specia Function 39 10 DIM A 80 T 10 20 PRINTER iS CRT 30 Nim 708 Noise Figure Meter address 40 Start 20 iStart Frequency 50 Stop 100 Stop Frequency 60 Step 20 Step Size 70 OUTPUT Nfm H2 Output second stage temperature and GkB during calibration 80 OUTPUT Nfm T1 ITrigger Hold 90 OUTPUT Nim FA St
220. d to store and recall instrument configurations or Excess Noise Ratio ENR tables When used to store and recall instrument configurations the STORE and RECALL functions are entered in a Function Data format It is not necessary to use the ENTER key to terminate data entry However ENTER has no effect if it is used Data is a single digit register number 0 through 9 When used to store and recall ENR tables the STORE and RE CALL functions are entered in a Function ENR Data format Itis not necessary to use the ENTER key to terminate data entry However ENTER has no effect ifitis used ENR isthe ENR key Dataisa single digit table number 1 through 4 Special Functions are entered in a Code SPECIAL FUNCTION format The code consists of a prefix decimal and suffix 7 1 is an example of a special function code where 7 is the prefix and 1 is the suffix If the suffix is zero the zero and the decimal point can be omitted when entering the code For example 7 SPECIAL FUNCTION is equivalent to 7 0 SPECIAL FUNCTION A Code SPECIAL FUNCTION Data ENTER format is used to acti vate and enter data for special functions that require data entry 3 3 Table 3 1 Operating Characteristics Noise Figure Corrected and Uncorrected Modes Range 0 to 30 dB _ Selectable Display Units F dB F Y dB Y Te K Insertion Gain Corrected Mode Only Range 20 to 40 dB Display Units dB Measurements Tuning Fixed Frequency
221. dB 810 MHz 9 43 FdB 910 MHz 9 73 FdB 1010 MHz 10 03 FdB 1110 MHz 10 83 FdB 1210 MHz 10 63 FdB 1310 MHz 10 93 FdB 1410 MHz 11 23 FdB 1510 MHz 11 53 FdB 4 10 SPURIOUS RESPONSE PERFORMANCE TEST Noise Figure Sig Gen Power Off 4 26 Step 9 Step 13 Step 17 Step 21 Step 26 Noise Figure Sig Gen Power On Step 8 Step 12 Step 16 Step 20 Step 27 HP 8970B Performance Tests Table 4 2 Performance Test Record 3 of 3 JITTER PERFORMANCE TEST Minimum Smoothing 5 X Standard Deviation Increased Smoothing 5 X Standard Deviation 4 27 4 28
222. ddress to display and change this address if necessary The default address is 19 after using Special Function 0 9 g The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 HP 8673B C Standard Synthesized Signal Generator Special Function 41 3 HP 8340B 8341B Sweep Oscillator Special Function 41 4 e Custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or output power Use Special Function 42 to define a new program for other system local oscillators h Ifa free running non synthesized source is being used as the system local oscil lator a Noise Figure Test Set Coarse Tuning Calibration should have been done when the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator was put together The coarse tuning is ONLY required when a free running source is the system local oscillator or repairs have been made to the Noise Figure Test Set For more information on the coarse tuning refer to the Noise Figure Test Set Y
223. ddress of the Noise Figure Test Set must match the Noise Figure Test Set address that is stored in the Noise Figure Meter Use Special Function 40 2 Noise Figure Test Set address to display and change the address if necessary The default address of the Noise Figure Test Set is 10 after using Special Function 0 9 e Special Function 46 0 must be active Enable system local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 f The address of the system local oscillator must match the address of the system local oscillator stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator System Interface Bus address to display and change this address if necessary The default address is 19 after using Special Function 0 9 g The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below e HP 8671B 8672A Synthesized Signal Generator Special Function 41 2 e HP 8673B C Standard Synthesized Signal Generator Special Function 41 3 HP 8340B 8341B Sweep Oscillator Special Function 41 4 e Custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix
224. de 1 6 a The Noise Figure Test Set and the system local oscillator must be connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 must be active Noise Figure Meter is the system controller on the system interface bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 45 0 must be active Noise Figure Test Set enabled in measure ment modes 1 5 through 1 9 Special Function 45 0 is the default setting after using Special Function 0 9 or Special Function 45 1 Noise Figure Test Set enabled always must be active HP 8970B Requirements cont d Procedure Operation Measurement Mode 1 6 conta Special Function 1 6 d The address of the Noise Figure Test Set must match the Noise Figure Test Set address that is stored in the Noise Figure Meter Use Special Function 40 2 Noise Figure Test Set address to display and change the address if necessary The default address of the Noise Figure Test Set is 10 after using Special Function 0 9 e Special Function 46 0 must be active Enable system local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 f The address of the system local oscillator must match the address of the system local oscillator stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator System Interface Bus a
225. de is W2 or AUTO sweep on HP IB code is W1 1 Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep m A method must be determined when to step to a new frequency after reading the noise figure results This read operation cannot be completed until the new data is ready It is possible to write an SRQ interrupt routine on the Data Ready Status Bit Refer to Enabling the Service Request Condition paragraph 3 30 n Continue to loop through steps 1 and m A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the measurement frequency that is read from Noise Figure Meter with the stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal Calibrate Controller Capability of the Noise Figure Meter Fixed IF or LO Frequency Selection Measurement Modes Noise Figure Test Set YIG Filter Calibration Sideband Selection Special Functions 3 175 Operation Description Requirements 3 176 HP 89706 Measurement Mode 1 8 Special Function 1 8 NOTE if the IF into the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and System Local Oscillator can be re duced below 1600 MHz Measurement Mode 1 3 is a better choice than Measurement Mode 1 8 Measurement Mode 1 3 requires l
226. dications Comments Related Sections Operation Sequence cont d Special Function 35 To set the register recall sequence to 1 2 7 2 and 5 mmm COE emanation Function SPECIAL FUNCTION Eaicalesles LOCAL keystrokes 0 0 010 01010101 BIBIBIBIBIBIEIBIB 7 OSTENZEN7TEN2ZENSENOENOENOENCEN gt Slate a program codes Data Data Function Function 8 Data Data Function Data Function Function Function Function The program code for the SEQ key is SQ The program code for the ENTER key is EN Refer to Procedure above for HP IB program codes for Special Function 35 When the Noise Figure Meter is in the manual sequence mode pressing the SEQ key causes the storage register being recalled to appear in the left display while the key is depressed When the Noise Figure Meter is in the automatic sequence mode the SPECIAL FUNCTION key LED lights Register numbers are not displayed during automaticsequencing Register numbers can be repeated in a sequence string If fewer than nine register numbers are used for a sequence string zeros should be entered so that the sequence always has nine digits in it For a list of front panel functions that can or cannot be stored and recalled therefore can or cannot be used in a sequence refer to Table 3 12 Front Panel Summary in the Preset Conditions and Power Up Sequence Detailed Operating Instruction For a list of special functions that can
227. e Fixed Frequency Tuning Special Functions Sweep HP 8970B Operation Special Function Catalog Special Function 50 Description Special Function 50 displays the contents of the eight line special functions catalog either sequentially or by individual line The catalog can be used to quickly determine the present status of many of the special functions For a concise explanation of the special function catalog refer to the Special Function Catalog Summary shown below Special Function 50 N displays the Special Function Catalog 50 0 SP sequences through 8 catalog tines 50 1 through 50 8 SP display the specified catalog line For example s 0 a a e Displays the N 7 line The first dispiayed digit N is the catalog tine number Each of the digits is the suffix of a specific Special Function as shown in the table beiow een SP Code suttixes This display indicates the following Special Functions 1 4 2 2 4 0 5 6 Digit positions Wo SPECIAL FUNCTION PREFIXES SP code prefixes N 1 a 1 2 4 5 2 1085 41 122 B 13 t6 14 i5 3 5 35 414 43 6 605 70 EL 2 l ee RE ee ee 8 49 NA L 36 N A 19 42 10 0 through 10 4SP 5 9 1SP 6 9 2SP 7 3SP 8 9 45P 23 12 1SP and 12 25P selected 3 indicates selected analog output O 3 7 0 through 7 3SP 4 22 0SP 5 23 0SP 6 24 0SP 7 82 0SP 4 indicates selected System LO program 0 41 0SP HP 8350B 2 41 2SP HP 8671B 8672A 3 41 3SP H
228. e The bit pattern can be inter preted with the information in the HP IB Syntax and Characteristics Summary HP 8970B Sending the Status Byte Message cont d Output Status Function After receiving the program code OS Output Status and when addressed to talk the Noise Figure Meter sends two binary bytes each 8 bits wide The first byte is identical to the Status Byte of the Serial Poll The second byteis the Extended Status Byte which provides additional information Refer to the HP IB Syntax and Char acteristics Summary for a description of each Status Byte Bits in the main Status Byte and Extended Status Byte are cleared upon execution of the Out put Status OS or Reset Status RS program code START HP 89708 SET TRIGGER SELECTION TO HOLD HP IB CODE T1 ENABLE SRQ ON DATA READY HP IB CODE Q1 CONFIGURE MEASUREMENT TRIGGER MEASUREMENT HP 1B CODE T2 PROCESS OTHER ROUTINES UNTIL SRQ CAUSES INTERRUPT TO OTHER INSTRUMENT SERVICE ROUTINES TEST OTHER HP 89708 SRQ CONDITIONS Operation 3 32 Clearing the Status Byte Once the Noise Figure Meter receives the serial poll enable bus command SPE itis no longer allowed to clear the Status Byte However it can add addi tional bits to the status byte if the bit has been enabled and the condition occurs After the Status Byte message has been sent it will be cleared if the Serial Poll Disabled SPD bus command is received i
229. e and control lines except DIO8 to both their true and false states These procedures do not check if all Noise Figure Meter program codes are being properly interpreted and executed by the instrument However if the power up sequence including the memory checks and the front panel operation is good the program codes in all likelihood will be correctly executed The validity of these checks is based on the following assumptions a The Noise Figure Meter performs properly when operated via the front panel keys that is in local mode This can be verified with the Basic Functional Checks b The bus controller properly executes HP IB operations c The bus controller s HP IB interface properly executes the HP IB operations If the Noise Figure Meter appears to fail any of these HP IB checks the validity of the above assumptions should be confirmed before attempting to service the instrument The select code of the controller s HP IB interface is assumed to be 7 The address of the Noise Figure Meter is assumed to be 8 its address as set at the factory This select code address combination that is 708 is not necessary for these checks to be valid However the program lines presented here have to be modified for any other combination These checks are intended to be as independent of each other as possible Nevertheless the first four checks should be performed in order before other checks are selected Any special initi
230. e vertical input On the Noise Figure Meter press 7 1 SPECIAL FUNCTION Verify that a test pattern is seen on the display It may be necessary to adjust rear panel GAIN TRACE control to obtain the test pattern The test pattern should be 6 0 5 volts vertically and horizontally Adjust the display until the test pattern fills the grid area see Figure 3 10 Press 7 0 SPECIAL FUNCTION to enable the Noise Figure Meter to output the noise figure and gain data to the display Figure 3 10 Test Pattern on Oscilloscope Calibration and SWEEP Check 6 Press CORRECTED NOISE FIGURE AND GAIN Verify the NOISE FIGURE display shows an error message NOTE In step 6 error code E20 not calibrated is normally displayed Press UNCORRECTED NOISE FIGURE Verify thatthe NOISE FIGURE display shows approximately 5 FdB indicating that the Noise Figure Meter can make uncorrected noise figure measurements prior to being calibrated Press CORRECTED NOISE FIGURE AND GAIN Verify the NOISE FIGURE display again shows an error message 3 16 HP 8970B Operation OPERATOR S CHECKS Basic Functional Checks cont d Procedure contd 9 10 11 12 13 NOTE All frequency data must be entered in MHz Press the following keys to enter the SWEEP calibration parameters a START FREQ 123 ENTER b STOP FREQ 789 ENTER c STEP SIZE 40 ENTER Press CALIBRATE twice Verify the following conditions a CALIBRATE annuncia
231. e 1 3 fixed IF Y Y Off Off Off Measurement variable freg sys LO Mode 1 3 mixer is DUT 1 4 E4 Mode 1 4 variable IF N Y Y Off Off Off Measurement fixed freq sys LO mixer Mode 1 4 is DUT Measurement Mode 1 5 10 to 18000 Measurement Mode Selection MHz Mode 1 5 Noise Figure Mode 1 6 fixed IF varia Measurement e ais ble user controlled LO Mode 1 6 8 iba Mode 1 7 variable IF Measurement fixed freq user controlled LO SSB Mode 1 8 fixed IF vari Mode 1 7 Measurement able user controlled LO Mode 1 8 mixer in DUT Mode 1 9 variable IF Measurement fixed user controlled LO Mode 1 9 mixer in DUT Sideband Frequency Offset Double Sideband no offset Lower Single Sideband F signal lt Fio Upper Single Sideband Faga gt Fro Signal Up Conversion IF F rignal Fio Sideband Selection Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable 3 239 Operation HP 8970B Table 3 14 Special Function Summary 2 of 15 a gt E e g Tacen E2 E er Sa Sb emi es Ss e OS s2 55 PE 58 4 ary Ce tale Meee D ua ee saa Sl ges sS Z2 SE References and Description 23 22 52 35 BE SS ood bbe EAD oer CS SE OO AS
232. e NOISE FIGURE display will increase by one If any values have been entered the ENR tabie number will be set to zero 3 89 Operation Procedure cont d Program Codes i gt Comments 3 90 HP 8970B ENR Table Entry conta 5 Repeat steps 3 and 4 as needed to make all ENR table entries 6 After all frequencies and ENR values have been entered the information must be stored to Table 1 2 3 or 4 Ifthe information is not stored it will be lost the next time one of the tables Tables 1 4 is recalled to Table 0 The store procedure will save the Noise Source identifier and the ENR data 7 To store the information key in the following sequence STORE ENR X X is the number of the table 1 4 where the information is stored When astoreis keyed in the INSERTION GAIN display shows Sto and the NOISE FIGURE display shows Enr After the table number is entered the displays return to what they were previously displaying 8 To terminate ENR table entry mode press FREQUENCY or send HP IB code FR Viewing Information on Stored ENR Tables Press 5 6 Special Function This special function will cause the following information to be displayed HH is the ENR source identifier T is the ENR table number NN is the number of entries in the table The INSERTION GAIN display does not have any information displayed in this mode Information on other tables can be viewed by using the UP ARROW and DOWN ARROW keys NOTE I
233. e Tuning Calibration IF Attenuation Selection Display IF Attenuator Settings IF Attenuator Hold Voltmeter Mode Recorder Test Functions Keyboard Test Display Test 0 MHz Hold RAM Inspection Modification or Sets the Address for Modification or Inspection ROM Inspection Utilities and Enables Auto Increment Mode Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code 3 56 HP 8970B Operation Table 3 9 Special Function to HP IB Code 7 of 7 Special Function HP IB pe Tr et Code Description Sets the Address for Modification or Inspection and Disables Auto Increment Mode 93 2 Selects Modification or Inspection of a Byte in RAM or Inspection of a Byte in ROM 93 3 Selects Modification or Inspection of a Word in RAM or Inspection of a Word in ROM 93 4 Selects Modification or Inspection of a Floating Point Value in RAM or Inspection of a Floating Point Value in ROM Noise Figure Meter YIG Filter 94 1 Disable Hysteresis Calibration when Frequency Tuning Functions is Changed 94 2 Enable Hysteresis Calibration when Frequency is Changed 94 3 YIG DAC is not Updated when Frequency is Changed 94 4 YIG DAC is Updated when Frequency is Changed Default ENR 95 5 Sets all ENR Values to 15 20 dB and Noise Source ID No to 00000 Debug Oscilloscope Plots 97 1 Enables Debug Oscilloscope Plots 97 2 Disables Debug Oscilloscope Plots Noise Figure Test Set Protection 97 3 Disa
234. e and talk only mode The remote opera tion instructions provide information pertinent to HP IB operation when the Noise Figure Meter isin the normal talker listener mode or the talk only mode Included are discussions on capabilities addressing input and output formats the status bytes and service requests At the end of the discus sion is a complete summary of all codes and formats In addition to the section described above infor mation concerning remote operation appears in several other locations The controller capability of the Noise Figure Meter is described in the Detailed Operating Instructions A summary of HP IB codes and output formats appear on one of the Operating Information pull out cards Numer ous examples of program strings appear through out the Detailed Operating Instructions 3 1 Operation 3 5 Operators Checks Operator s Checks are procedures designed to verify the proper operation of the Noise Figure Meter s main functions Also Operator s Checks are provided for the Noise Figure Measurement System Three procedures are described below Basic Functional Checks This procedure requires only a noise source an oscilloscope or a display module and interconnecting cables It assures that most front panel controlled functions are being properly executed by the Noise Figure Meter i gt HP IB Functional Checks These proce dures require an HP IB compatible computing controller an HP IB int
235. e average of those readings Vavg 15 dB Compute the 15 dB attenuator value as shown Result from step 11 Vref2 Vavg 15 dB gt 26 607 lt 37 584 for 15 dB attenuator On the Noise Figure Meter press 70 5 SPECIAL FUNCTION to switch in the internal 20 dB attenuator Take 10 voltmeter readings Then calculate and record the average of the readings Vavg 20 dB Compute the 20 dB attenuator value as shown Result from step 11 Vref2 Vavg 20 dB nmm gt 84 140 118 850 for 20 dB attenuator On the voltmeter select internal triggering If the voltmeter has filtering turn it off Reduce the 10 dB step attenuator by 10 dB and adjust the 1 dB step attenuator until the voltmeter reads as close to 1 volt as possible On the voltmeter select single triggering If the voltmeter has filtering turn it on Take 10 voltmeter readings Using at least four digits to the right of the decimal point calculate and record the average of the readings This is a reference voltage used in the 25 dB and 30 dB attenuator calculations Vref3 On the Noise Figure Meter press 70 6 SPECIAL FUNCTION to switch in the internal 25 dB attenuator Take 10 voltmeter readings Then calculate and record the average of the readings Vavg 25 dB Compute the 25 dB attenuator value as shown Result from step 16 Vref3 Vavg 25 dB nmm 266 07 lt 376 84 for 25 dB attenuator On the Noise Figure Meter press 70 7 SPECIAL FUNCTI
236. e display units are as follows noise power added by DUT noise power out due to source noise power out due to source when the source is a 290K F dB 10 log F y power measured with noise source On power measured with noise source Off Y dB 10 log Y Thot Yx Toia Y Te where Tao is the equivalent temperature of the noise source when it is On and Ta is the equivalent temperature of the noise source when it is Off Related Display Resolution Sections Noise Figure Uncorrected and Noise Figure and Gain Corrected Smoothing Special Functions 3 86 HP 89708 Description Procedure Operation ENR Table Entry The ENR key is used to store recall or display an ENR Excess Noise Ratio table The Noise Figure Meter can store the ENR tables for five noise sources Each table can have up to thirty five frequency ENR pairs This information is used to improve the accuracy of the noise figure and gain calculations made by the Noise Figure Meter The information entered is the actual Excess Noise Ratio ENR value at the specified frequency All noise sources have this calibration information available In the case of the HP 346A B and C Noise Sources a separate printout is supplied and a graph or table is printed on the side of the Noise Source showing the ENR versus Frequency data The frequency ENR pairs shown on the printout or graph are the values that are entered into one of the ENR tables The valid frequen
237. e general operation of the instrument Simplified Operation The instructions located on the inside of this fold provide a quick introduction to front panel operation of the Noise Figure Meter These instructions are designed to rapidly ac quaint the new user with basic operating proce dures and therefore are not an exhaustive listing of all Noise Figure Meter functions However an index to the Detailed Operating Instructions ap pears opposite the fold to direct the operator to the more complete discussion of the topic of interest Panel Features Front and rear panel features are described in detail in Figures 3 1 through 3 8 Detailed Operating Instructions The Detailed Oper ating Instructions provide the complete operating reference for the Noise Figure Meter user The instructions are organized alphabetically by sub ject and are placed at the end of this section for easy reference They are indexed by function in Table 3 2 Operating information Pull Out Cards The Operat ing Information pull out cards are three flexible plastic reference sheets located in a tray below the front panel They contain a listing of user special functions HP IB output formats error codes and measurement modes 3 4 Remote Operation GH The Noise Figure Meter is capable of remote oper ation via the Hewlett Packard Interface Bus HP IB In remote operation the Noise Figure Meter operates in one of two modes normal talker lis tener mod
238. e old frequencies that surround the new entry The new frequency and ENR value can be entered using the procedure in steps 2 through 4 If data is read over the Hewlett Packard Interface Bus from the Noise Figure Meter during ENR Table Entry the Noise Figure Meter will output a special HP IB code for the NOISE FIGURE window For more information about this special HP IB code refer to the Error Messages and Recovery Detailed Operating Instruction HP 8970B Procedure cont d 1 Operation ENR Table Entry conta If anew ENR table is being entered go to step 2 If an existing ENR table is to be edited continue with this step If the table to be edited is not in Table 0 the table will have to be recalled Use the following key sequence to recall an existing ENR table RECALL ENR X X is the number of the table 1 4 to be recalled When doing a recall rel appears in the INSERTION GAIN display and Enr appears in the NOISE FIGURE display When the table number is keyed in the displays return to what they were displaying before the recall was done Press the ENR key The displays will be as shown below FFFF EEEE FFFF is the first frequency in Table 0 EEEE is the ENR for the first frequency in Table 0 T is the ENR table number in this case 0 NN is the ENR table entry number 1 through 35 NOTE When editing T is the number of the most recently recalled table T will be zero if a change has been made to t
239. e to test this specification automatically This specification is statistical in nature The truly correct way to make the measurement would be to take several hundred measurements to ensure a statistically valid sample has been gathered Noise Source ccccesccscctcccsssesaes HP 346B Opt 001 1 Turn on the Noise Figure Meter and allow a 1 hour warm up 2 Press PRESET to set the instrument to standard conditions Connect the noise source directly to the INPUT connector 3 Key in 10 2 SPECIAL FUNCTION to set the instrument to read Y factor in dB 4 Key in 30 1 SPECIAL FUNCTION to set the instrument to trigger hold 5 Execute 30 2 SPECIAL FUNCTION 100 times to get 100 separate readings Record the readings If you are using a computer or a calculator with statistical computa tion capabilities that is standard deviation enter the data points as they are read from the Noise Figure Meter 6 Find the standard deviation If you are using a calculator that does not have the standard deviation function first calculate the mean Mean Total of all data points Number of readings Mean HP 8970B Performance Tests PERFORMANCE TESTS JITTER PERFORMANCE TEST cont d Procedure cont d Then compute the standard deviation x 2 X mean i N 1 for N 100 Standard Deviation Multiply the standard deviation by 5 The result should be lt 0 15 dB Ifthe result is gt 0 15 dB perform steps
240. e to be defective For warranty service or repair this product must be returned to a service facility designated by HP Buyer shall prepay shipping charges to HP and HP shall pay shipping charges to return the product to Buyer However Buyer shall pay all ship ping charges duties and taxes for products returned to HP from another country HP warrants that its software and firmware designated by HP for use with an instrument will execute its programming instructions when properly installed on that instrument HP does not warrant that the operation of the instrument or software or firmware will be uninterrupted or error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inade quate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HP SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPE CIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY ASSISTANCE Product maintenance agreements and other customer assistance agreements are ava
241. ear E26 first enter the IF atten uator values by following the procedure in step 26 Then perform the following I Key in 93 0 SPECIAL FUNCTION 2 Subtract 1 from the value recorded in step 261 Enter this value into the Noise Figure Meter and then press ENTER 3 Key in 93 2 SPECIAL FUNCTION Then key in 128 and press ENTER 4 Press FREQUENCY to return to normal operation Gain Measurement Uncertainty Performance Test 27 On the Noise Figure Meter press PRESET NOTE This procedure relies critically upon the proper setup of the power meter If readings yield results that are out of specification check that the cali bration adjustment and zero setting of the power meter are valid Always disconnect the power sensor from the test setup when zeroing 28 Connect the equipment as shown in Figure 4 4 POWER METER STEP 28 3 20 dB F ATTENUATOR CE E POWER SPLITTER STEP 40 10 dB ATTENUATOR WIDE BAND AMPLIFIER WIDE BAND AMPLIFIER Hl Figure 4 4 Gain Measurement Uncertainty Test Setup 4 16 HP 8970B Performance Tests PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure 29 cont d 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 On the Noise Figure Meter press the ENR key to access the working ENR table with in the Noise Figure Meter Using the DATA keys and the ENTER key modify the
242. ecial Functions 42 0 through 42 7 and the data that can be modified by each special function The following conventions are used in the program listings a All HP IB program codes consist of ASCII characters The numbers and letters shown before the parentheses in Special Functions 42 0 42 1 and 42 5 through 42 7 are the ASCII characters that make up valid HP IB program codes There is one exception the custom local oscillator program Count is not ASCII Count is used to show the position in the program where the prefix and suffix count characters are to be placed The count character indicates the number of characters in the prefix or suffix 3 211 Operation HP 8970B Programming The System LO conta Special Function 42 Predefined System LO Predefined Program Listings Program Listings HP8340B 83418 cei cont d System LO Commands 41 4 or HP 8671B 8672A HP 8673B C deat Local Oscillator Special Function 42 HP aor Program 41 2 Program 41 3 Program 41 5 42 0 Auxiliary R 82 Commands 1 49 D 68 0 48 A 65 haa S 83 f 0 48 T 84 P 80 A 65 0 48 T 84 Space 32 0 O 79 0 0 0 0 0 0 0 i 0 C 67 P 80 F 70 Special Function W 87 255 R 82 42 1 is not used M 77 Z 90 M 77 with Special Z 90 0 48 Z 90 Function 41 5 Refer to Specia Function 42 7 42 2 Settling Time 60 ms 20 ms 30 ms 30 ms 42 3 Minimum 2000 MHz 2000 MHz 2000 MHz 10 MHz
243. ed local oscillator For more information on using an external controller refer to Comments at the end of this instruction To make a swept CORRECTED NOISE FIGURE AND GAIN measurement of a wideband amplifier in the 20 to 30 GHz range using 200 MHz steps 3 170 HP 8970B Operation Measurement Mode 1 7 conta Special Function 1 7 Example a Press PRESET or send HP IB code PR to establish initial conditions PRESET cont d selects a single sideband measurement Special Function 17 0 for the Noise Figure Test Set NOTE Measurement Mode 1 7 must be activated prior to entering the fre quency parameters to avoid error E35 entered value is out of range b Press 1 7 SPECIAL FUNCTION or send HP IB code E7 to activate Mode 1 7 Note that error E33 IF will be out of range is displayed This error is cleared when the correct frequency parameters are entered in step d c Press 2 1 SPECIAL FUNCTION or send HP IB code B1 or 2 1SP to select a lower sideband measurement Special Function 2 1 is used to select single sideband operation for the first frequency conversion using the user controlled loca oscillator and the externa mixer NOTE When a single sideband measurement is being made the user must place a filter between the device under test and the external mixer to eliminate the unwanted sideband d Set the frequency parameters for both the calibration and measurement e Enter the noise source ENR table if this has no
244. ed the local oscillator is HP IB compatible However a thorough understanding of the HP IB program requirements and restrictions that apply to the system local oscillator is required The custom local oscillator program is different from the other predefined system LO programs The other programs will only support a frequency prefix or suffix of two characters maximum The same is true for the power prefix or suffix The custom local oscillator program will support a system LO that could require a maximum of twenty two characters in the prefix and suffix This is true for frequency and power The five predefined system LO programs are stored in permanent memory ROM Activating Special Function 41 0 41 2 41 3 41 4 or 41 5 loads the corresponding predefined program from permanent memory into temporary memory RAM The programs stored in the permanent memory are never changed only the program in temporary memory can be modified Special Function 42 can change the program data that is stored in the temporary memory One of the predefined programs or the last modified program is always present in the temporary memory And only the program in temporary memory can control the system LO Detailed examples will be used to explain the use of Special Function 42 However a brief definition of the purpose of the individual parts of the program that can be changed using Special Function 42 will make the programs easier to understand a Special Funct
245. ed twice the Noise Figure Test Set s YIG filter is fine tuned Then 3 29 Operation HP 8970B OPERATOR S CHECKS Noise Figure Measurement System Check cont d Procedure cont d the Noise Figure Measurement System is calibrated During the Noise Figure Test Set s YIG filter fine tuning the following indications will be seen on the Noise Figure Meter Noise Figure Test Set and System Loca Oscillator NOTE The fine tuning calibration will take from twenty five to thirty seconds to complete Noise Figure Meter a Each point that is being fine tuned and is included in band SSB3 single side band 3 on the Noise Figure Test Set 2401 to 18000 MHz is displayed in the left display Frequency points that are included in bands SSB1 single sideband 1 on the Noise Figure Test Set 10 to 1600 MHz or SSB2 single sideband 2 on the Noise Figure Test Set 1601 to 2400 MHz are not displayed b 8971 appears in the INSERTION GAIN display c CAL appears in the NOISE FIGURE display Noise Figure Test Set a The REMOTE annunciator is on b The LISTEN annunciator will flash c The annunciators for SSB1 SSB2 and SSB3 will be stepped from SSB1 to SSB2 to SSB3 System Loca Oscillator a The REMOTE annunciator is on b The LISTEN annunciator will flash c The FREQUENCY display will move around When the Noise Figure Test Set YIG filter fine tuning is complete the Noise Figure Measurement System is
246. eiver All of the Measurement Modes can be set to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements Or the measurement results for each mode can be displayed on an oscilloscope or output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measure ment Mode and sideband operation refer to the Measurement Modes Detailed Operat ing Instructions The following minimum requirements are necessary for the Noise Figure Measurement System and user controlled local oscillator to operate in Measurement Mode 1 8 a Thesystem local oscillator and the Noise Figure Test Set must be connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 must be active Noise Figure Meter is the controller on the system interface bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 45 0 must be active Noise Figure Test Set enabled in measure ment modes 1 5 through 1 9 Special Function 45 0 is the default setting after using Special Function 0 9 or Special Function 45 1 Noise Figure Test Set enabled always must be active HP 8970B Requirements cont d Procedure Operation Measurement Mode 1 8 conta Special Function 1 8 d The a
247. ement Modes 1 5 and 1 9 e 10 to 99999 MHz in Measurement Modes 1 1 through 1 3 and 1 6 through 1 8 The Measurement Mode determines the default for fixed frequency tuning The defaults are given in the table below As shown in the table above the Measurement Modes have been placed into groups If the fixed frequency is changed for one Measurement Mode the fixed frequency is changed for all the Measurement Modes of the group When going from one Measurement Mode to another the previous fixed frequency is automatically saved by the Noise Figure Meter The tuned fixed frequency of the instrument can also be changed by using a combination of the FREQ INCR key to set the increment size and the W and keys to step the fixed frequency in the selected direction The FREQUENCY key acts as a clear entry key It clears entries in progress returns the instrument to the last selected measurement with the left display showing the current tuned frequency and halts the sweep if it is in progress To display the current tuned frequency and enter a new tuned frequency press FREQUENCY enter the value of the new frequency in MHz and press ENTER Program Stored in Can Be Preset and Special cD Continuous Stored and HP IB Clear Function 0 9 Front Panel Key Memory Recalled Conditions Conditions Table categories are described in the Preset Conditions and Power Up Sequence Detailed Operating Instruction HP 8970B Example
248. ement frequency greater than LO frequency Signal Up Conversion B3 or 2 8SP IF Faigna plus Fro Single Sideband measure B4 or 17 0SP ment for Noise Figure Test Set input frequencies gt 2400 MHz Double Sideband measurement for Noise Figure Test Set input frequencies gt 2400 MHz Lower and Upper side band cross over frequency Table categories are explained in the Special Functions Detailed Operating Instruction B5 or 17 1SP CF or 17 2SP HP 8970B Example Program Codes Indications Related Sections Sideband Selection conta Special Functions 2 and 17 To select lower single sideband frequency offset LOCAL wae Code Function iii CILAN Jm gt program codes For HP IB codes refer to Procedure Operation For indications refer to the Lights Special Function Key column in the table in Procedure above Measurement Modes Measurement Modes 1 1 through 1 9 Special Functions 3 229 Uperation Description Procedure 3 230 HP 8970B Smoothing Averaging Includes Special Function 13 The purpose of smoothing is to reduce jitter in both the NOISE FIGURE and INSERTION GAIN displays Numbers that are sent to both of these displays are averaged before being displayed The Noise Figure Meter has two modes of smoothing exponential and arithmetic straight averaging The equation for exponential smoothing is new measurement n
249. ements cont d Power Measurements 0005 3 200 Trigger Selection eeceeeeuee 3 273 Miscellaneous Data Output to Oscilloscopes Recorders and Plotters nasesesasesuenureosens 3 73 Error Messages and Recovery 3 93 Preset Conditions and Power Up Sequence s ossssessusenrrasserersr gt 3 205 Seguente cierren e AAEE A EENE 3 224 Store and Recall ccc cece cee eee es 3 257 Programs Programming the System LO 3 210 Programs Available to Control the System LO ie chines che ie sine dseeeesies 3 219 Special Functions Calibration Frequency 00005 3 65 Calibration IF Attenuators 3 67 Calibration Input Gain Selection 3 69 Controller Capability of the Noise Figure Meter ccccuceaee 3 71 Data Output to Oscilloscopes Recorders and Plotters 60k 6i ch ied Sen cate toe 3 73 Display Control ccc c cece eee cace 3 81 Display Resolution 0000 3 83 Display Units Selection 3 85 Fixed IF or LO Frequency Selection 3 110 HP IB and System Interface Bus SIB PO GTOGBOG 5 65565 cee hac ieten nens ORS owe 3 113 IF Attenuation Selection 3 117 Loss Compensation ccecees 3 119 Manual Measurement Functions 3 121 Measurement Mode 1 0 0000 3 132 Measurement Mode 1 1 cceceaee 3 135 Measurement Mode 1 2
250. en ON and then press the PRESET key Then press 4 0 SPECIAL FUNCTION HP 85B HP 9000 Series 200 300 Send the first part of the Remote message REMOTE 7 REMOTE 7 enabling the Noise Figure Meter to remote LOCAL Send the Local Lockout message LOCKOUT 7 LOCAL LOCKOUT 7 Address the Noise Figure Meter to listen OUTPUT 708 OUTPUT 708 completing the Remote message Operator s Check that both the Noise Figure Meter s REMOTE and LISTEN annunciators are on Response Press the Noise Figure Meter s LOCAL key Both its REMOTE and LISTEN annuncia tors should remain on Send the Clear Lockout Set Local message LOCAL 7 Operator s Check that the Noise Figure Meter s REMOTE annunciator is off but its LISTEN Response annunciator is on Clear Message Note This check determines if the Noise Figure Meter properly responds to the Clear mes sage This check assumes that the Noise Figure Meter is able to handshake recognize its own address make the remote local changes and receive Data messages Before beginning this check press the Noise Figure Meter s PRESET key When Fr dis appears from the INSERTION GAIN display and CAL disappears from the NOISE FIGURE display press CALIBRATE twice Once the LED above the CALIBRATE key turns off press 4 0 SPECIAL FUNCTION 3 24 HP 8970B Operation gt OPERATOR S CHECKS HP IB Functional Checks cont d Clear Message cont d HP 858 HP 9000 Series 260 30
251. ept that a Sweep is always off b The measurement is always UNCORRECTED NOISE FIGURE c The instrument always turns on in local mode instead of HP IB remote d Calibration data is not retained when power is removed e Special Functions 25 30 through 32 35 1 43 44 49 2 through 49 4 and 60 through 72 are not remembered when power is removed Preset Functions The Noise Figure Meter has three levels of preset Special Function 0 9 PRESET and Special Function 0 0 Special Function 0 9 is the upper level of preset Special Function 0 9 sets all conditions set by PRESET and Special Function 0 0 and sets default values for some special functions not set by PRESET Special Function 0 9 does not reset the ENR Excess Noise Ratio tables and does not clear the IF calibration data PRESET is the second level of preset PRESET sets all conditions set by Special Function 0 0 and sets the default values for some of the special functions Special Function 0 0 is the lowest level of preset More detail is given for Special Function 0 9 PRESET and Special Function 0 0 in the following text Special Function 0 9 and PRESET Special Function 0 9 and the PRESET key set the Noise Figure Meter to a known state The front panel is set to the conditions listed in the Special Function 0 9 Preset and HP IB Clear Conditions column in Table 3 12 Front Panel Summary Table 3 13 lists the default data values that are set by Special Function 0 9 and PR
252. equency parameters e Select sideband operation desired Special Function 17 f Select appropriate smoothing Special Function 13 g Perform a Noise Figure Test Set Fine Tuning Calibration Refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction LID onan HP 8970B Operation Measurement Mode 1 5 conta Special Function 1 5 Procedure h Calibrate in Mode 1 5 this is only required fora CORRECTED NOISE FIGURE AND GAIN measurement If a preamplifier is required for the measurement the preamplifier must be used in the calibration i Insert device under test DUT and measure Example To make a swept CORRECTED NOISE FIGURE AND GAIN single sideband meas urement in the 3000 to 4000 MHz range in 10 MHz steps a Press PRESET to establish initial conditions Single sideband Special Function 17 0 is active when PRESET is pressed b Press 1 5 SPECIAL FUNCTION to set the Noise Figure Measurement System to Measurement Mode 1 5 c Set the frequency parameters for both the calibration and measurement d Enter actual ENR for the Noise Source if this has not previously been done gum COGE ame Function ummm YAA Senet Function OOO ore wa o O OOOO OOOm STEP ERIC ESFAS000MZFB4000MZSS10MZ Code aa D TC Function I HP iB 4 Code Data Data Code program codes Function Function Code Data e Tocalibrate and perform a Noise Figure Test Set Fine Tuning Calibration set up the equi
253. equency up or down by the current frequency increment Program Stored in Can Be Preset fand Special Code Continuous Stored and HP IB Clear Function 0 9 Front Panel Key i gt Memory Recalled Conditions Conditions FREQ INCR FN Y Y 20 MHz gt UP _ wv DN Table categories are described in the Preset Conditions and Power Up Sequence Detailed Operating Instruction 3 105 Operation Example Program Codes indications Comments 3 106 HP 8970B Fixed Frequency Increment conta To set the frequency increment to 50 MHz Function occ G 12 snc Function LOCAL i aii peat Ow E gt FN50MZ program codes Code ae T Function ata To decrease the tuned frequency by the current frequency increment LOCAL Function keystrokes 2 program codes Holding either the M or key down causes the frequency to step continuously However the frequency is slower to change when stepped downward In addition to the HP IB program codes given in Procedure above HZ and MZ are the program codes for Hz and MHz respectively l The currently programmed frequency increment is displayed in the left display for as long as the FREQ INCR key is depressed After FREQ INCR is pressed the new frequency increment data can beentered This data is displayed in the left display until the ENTER key is pressed The function is then implemented and the instrument returns to the last se
254. er is enabled to remote that is REN is set true and it receives the Local Lockout message it will switch to remote mode with local lockout the first time itis addressed to listen When in local lockout the Noise Figure Meter can be returned to local only by the controller using the Loca or Clear Lock out Set Local messages or by setting the LINE switch to OFF and back to ON or by removing the bus cable 3 27 Receiving the Clear Lockout Set Local Message The Clear Lockout Set Local message is the means by which the controller sets the Remote Enable REN bus control line false The Noise Figure Meter returns to local mode full front panel con trol when it receives the Clear Lockout Set Local message No instrument settings are changed by the transition from remote with local lockout to local When the Noise Figure Meter goes to local mode the front panel REMOTE annunciator turns off 3 28 Receiving the Pass Control Message The Noise Figure Meter does not respond to the Pass Control message because it does not have this control capability 3 29 Sending the Require Service Message The Noise Figure Meter sends the Require Service message by setting the Service Request SRQ bus contro line true The instrument can send the Require Service message in either local or remote mode The Require Service message is cleared when a seria poll is executed by the controller or if a Clear message is received by the Noise Figure
255. er to the Preset Conditions and Power Up Sequence Detailed Operating Instruction If either of these keys are pressed during the frequency calibration portion of the sequence thatis Fr CAL is being displayed calibration is not terminated These commands cannot be used until the frequency calibration is completed The calibration data cannot be stored using the STORE key and itis not retained when the instrument is turned off Therefore itis necessary to calibrate the instrument each time power is turned on 3 61 Operation Comments cont d 3 62 HP 8970B Calibrate contd includes Special Function 39 If smoothing averaging is used during calibration the arithmetic averaging algo rithm is used Refer to the Smoothing Averaging Detailed Operating Instruction for a detailed discussion of the averaging techniques used by the instrument A smoothing factor of 4 or 8 is recommended for the most accurate calibration Note that once calibration is initiated the SMOOTHING keys are disabled and the averaging factor cannot be changed during the calibration sequence If an external controller is being used to control both the Noise Figure Meter and the system local oscillator or the Noise Figure Measurement System and the user controlled local oscillator the calibration sequence must be stepped using the HP IB commands T1 Trigger hold and T2 Trigger execute after the local oscillator has been moved to each new frequen
256. ered over the Hewlett Packard Interface Bus HP IB For more information refer to the Comments section at the end of this instruction Specific calibration setups and procedures are contained in the Detailed Operating Instructions for Measurement Modes 1 0 through 1 9 To initiate a calibration sequence press CALIBRATE The message Press Cal will be displayed Press CALIBRATE again Pressing the CALIBRATE key twice ensures that the CALIBRATE key is not inadvertently pressed To terminate calibration before it is complete press CALIBRATE again Pressing PRESET also terminates the calibration sequence To select Special Function 39 0 or 39 1 enter the code desired and press the SPECIAL FUNCTION key 3 59 Operation Procedure cont d Example 3 60 HP 8970B Calibrate cont d includes Special Function 39 Preset and Special Program Stored in Can Be Code Continuous Stored and HP IB Clear Function 0 9 Front Panel Key Memory Recalled Conditions Conditions Table categories are described in the Preset Conditions and Power Up Sequence Detailed Operating Instruction x n 5 amp Ss LS my a v O amp Sg a 9S e T S 2 x Sz s Eee i se i B zE J5 SE SS s Specia Function Program oj as siaj es i 2 2 2585 s2 38 sz 38 Code aif 6 so Shi oa Ss 2 E w oe o D a D inti St ss am E os g oC ie a escr
257. erface and connecting cable The HP IB Functional Checks assume that front panel operation of the Noise Figure Meter has been verified by performing the Basic Func tional Checks The procedures check all of the applicable bus messages summarized in Table 3 3 Noise Figure Measurement System Check This procedure only requires the Noise Figure Measure ment System Noise Figure Meter Noise Figure Test Set and System Local Oscillator and a noise source The check assures that the Noise Figure Measurement System is operating properly 3 6 Operator s Maintenance For continued protection against fire hazard replace the line fuse witha 250V fuse of the same rating only Do not use repaired fuses or short circuited fuse holders Operator s maintenance consists of replacing blown fuses and cleaning the air filter _ The primary power fuse is located within the Line Power Module A15 Refer to Figure 2 1 forinstruc tions on how to change the fuse The rear panel fan has a filter inserted from the outside for ease of cleaning or replacement To service the filter disconnect power from the instru ment and remove the filter by pulling it from the rear of the fan To clean the filter hold it under running water or wash itin warm soapy water and then rinse it in clear water Dry the filter thor oughly before putting it back into place 3 2 HP 8970B NOTE The internal battery should be replaced once a year by qualified se
258. erformance are given in Sec tion IV If the contents are incomplete if there is mechanical damage or defect or if the instrument does not pass the electrical performance tests no tify the nearest Hewlett Packard office If the shipping container is damaged or the cushioning material shows signs of stress notify the carrier as well as the Hewlett Packard office Keep the shipping materials for the carrier s inspection 2 3 PREPARATION FOR USE 2 4 Power Requirements The Noise Figure Meter requires a power source of 100 120 220 or 240 Vac 5 to 10 48 to 66 Hz single phase Power consumption is 150 VA maximum This is a Safety Class I product that is provided with a protective earth termi nal An uninterruptible safety earth ground must be provided from the main power source to the product input wiring terminals power cord or supplied power cord set Whenever it is likely that the protection has been impaired the product must be made inoperative and be secured against any unintended operation If this instrument is to be energized via an external autotransformer make sure the autotransformer s common terminal is connected to the neutral that ts the grounded side of the Mains supply 2 5 Line Voltage and Fuse Selection CATTION BEFORE PLUGGING THIS INSTRU MENT into the Mains line voltage be sure the correct voltage and fuse have been selected Verify that the line voltage selection card and t
259. erything that is set by PRESET or Special Function 0 0 and more When Special Function 0 9 is selected it doesn t have any effect on the ENR tables or the IF calibration data Special Function 0 9 does set the defaults for all Hewlett Packard Interface Bus HP IB and System Interface Bus SIB addresses and the system local oscillator programs To use a Special Function key in the corresponding code then press the SPECIAL FUNCTION key To select Measurement Mode 1 1 Special Function 1 1 ammm Cole en Function LOCAL keystrokes 1 a 4 e AtA HPs d program codes The numeric code appears in the left display as it is being entered Pressing the SPECIALFUNCTION key activates the selected Special Function Refer to the Lights Special Function Key column in Table 3 14 for a list of Special Functions that light the key LED Calibration Frequency Calibration IF Attenuators Calibration Input Gain Selection Controller Capability of the Noise Figure Meter Data Output to Oscilloscopes Recorders and Plotters Display Control Display Resolution Display Units Selection Fixed IF or LO Frequency Selection HP IB and System Interface Bus SIB Addresses IF Attenuation Selection Loss Compensation Manual Measurement Functions Measurement Mode 1 0 Measurement Mode 1 1 Measurement Mode 1 2 Measurement Mode 1 3 Measurement Mode 1 4 HP 8970B Related Sections cont d Operation Special Functions
260. ese are User Special Functions which are used during normal instrument operation when a special configuration a special measurement or special information is required These Special Functions are described in the Special Function Summary Table 3 14 Prefixes 50 to 59 These are Catalog Special Functions and are used to display the status of Special Function settings Refer to the Special Function Catalog Detailed Operating Instruction for additional information Prefixes 60 to 79 These are Auxiliary Special Functions which are normally used for servicing the Noise Figure Meter However some of these Special Functions must be used for manual measurements HOT and COLD Refer to Section VIII Service and the IF Attenuation Selection and RF Attenuation Selection Detailed Operating Instructions for additional information Prefixes 80 to 99 These are the Service Special Functions used to assist in troubleshooting an instrument fault The functions available are quite diverse special internal measurements software control and special service tests and configura tions These Special Functions are discussed in detail in Section VHI Service Special Function Summary Table A summary of User Catalog and Auxiliary Special Functions is given in Table 3 14 Most of the Special Functions are explained in more detail in other operating instructions The Lights Special Function Key column indicates which Special Functions when
261. esesreresrena Selecting the SIB Address 040 Accessories Supplied eee ceceees Equipment Required But Not Supplied Electrical Equipment Available HP IB Controllers 6c b5csces oh eedacee ys External Mixers and System Local OBGINALOTS i253 bots och cceed teecaule ds Waveguide Coax Adapters Front to Rear Panel Connector Retrofit Kit o3h203 5 aacees vad cater nnas en Mechanical Equipment Available Chassis Slide Mount Kit 005 Chassis Tilt Slide Mount Kit Recommended Test Equipment Section Il INSTALLATION Introduction 0 cece cece ee ececcaeeace Initial Inspection 00 ccc c eee ences Preparation For Use c0ceeeeee Power Requirements 00eccee Line Voltage and Fuse Selection Power Cables cccccecescccusveces HP 8970S Noise Figure Measurement System di pti ceca ni hadeaess wimeeksoew tan Mating Connectors 0c cece cece ee ues Operating Environment 0065 Bench Operation 0 2 ccc ee eceneeeee Rack Mounting E Sata de a T nn a e a ee General Contents CONTENTS Page Page Recording IF Attenuator Values 2 5 Storage and Shipment 0ccceeceeeees 2 5 ee 141 Environment sssssesssversrrasrererrssre 2 5 rw 1 1 PACKAGING o iorersira inaina dan EOE TES 2 5 bette L i reve lA Se
262. ess equipment less noise figure is contributed by the measurement system and a pre amplifier may not be required for the measurement The HP 8971B Noise Figure Test Set a system local oscillator and a user controlled local oscillator are required for Measurement Mode 1 8 Measurement Mode 1 8 uses two stages of frequency conversion The user controlled local oscillator and the device under test provide the first stage of conversion The user controlled local oscillator is not controlled by the Noise Figure Meter the user controlled local oscillator must be controlled by the user The second stage of conversion is provided by the system local oscillator and the Noise Figure Test Set The Noise Figure Meter does control the system local oscillator and the Noise Figure Test Set Measurement Mode 1 8 provides the means of increasing the frequency range of the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator from 18000 MHz to 99999 MHz This mode uses a variable user controlled local oscillator and a fixed IF Frequency conversion is allowed for in the device under test DUT Although the signal measured at the Noise Figure Measure ment System INPUT is always in the range of 10 to 18000 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency However the correct 10 to 18000 MHz ENR is used during calibration Atypical DUT is a mixer or rec
263. essed However if the instrument was sweeping either in AUTO or SINGLE it does not resume sweeping Instead it performs the previously selected measurement at the frequency it was tuned to when CALIBRATE was pressed The maximum number of frequency points that can be calibrated is 181 for the Noise Figure Meter frequency range 10 MHz to 1600 MHz or the Noise Figure Measurement System frequency range 10 MHz to 18000 MHz For the Noise Figure Measurement System this is approximately 100 MHz steps for the full range When a calibration is done in Measurement Modes 1 5 through 1 9 and Special Function 36 0 is active the Noise Figure Test Set is calibrated before the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and System Local Oscillator calibration 8971 CAL is displayed on the Noise Figure Meter during the Noise Figure Test Set calibration For more information refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction During calibration all of the front panel keys except LOCAL PRESET and CALIBRATE are disabled If LOCAL is pressed during calibration the instrument returns to local control if it was in remote and the Local Lockout command was not in effect Calibration is not interrupted by the LOCAL command Pressing PRESET or CALIBRATE terminates the calibration function However PRESET also resets the entire instrument to a specified set of conditions ref
264. etain the data Special Function 42 1 allows for modification of the CW prefix and suffix commands Special Functions 41 0 through 41 4 ONLY for the system local oscillator program The prefix is the system LO s HP IB program code for CW The suffix is the system LO s program code for MHz The CW prefix and suffix commands are entered in a manner similar to the auxiliary commands that is the decimal equivalent of each ASCII character is entered into the Noise Figure Meter However the prefix and suffix HP IB program codes must each be two ASCII characters or less because only four data locations are available for this Special Function Enter zeros in any data locations that are not used The allowable range of decimal values is 0 to 255 For Special Functions 42 2 through 42 5 the decimal value is entered directly into the Noise Figure Meter The settling time is entered in ms The allowable range is 0 to 65530 ms Frequency is entered in MHz The allowable range is 0 to 99999 MHz The output power is entered in dBm The allowable range is 0 to 30 dBm Special Function 42 6 is ONLY used with the custom local oscillator program Special Function 41 5 Special Function 42 6 is used to properly format the command sequence that is used to set the output signal power level Special Function 42 6 allows entry of the prefix and suffix for the output signal power level The count character for the prefix the prefix characters the count characte
265. ever this technique has some disad vantages a It defeats the purpose and advan tage of local lockout that is the system controller will lose control of a system element b There are several HP IB conditions that reset to default states at turn on 3 19 Data Messages The Noise Figure Meter communicates on the interface bus primarily with data messages Data messages consist of one or more bytes sent over the bus data lines when the bus is in the data EXAMPLE 1 Typical Program String Controller Talk Noise Figure Meter Start Frequency Set to 100 MHz Stop Frequency Set to 150 MHz HP 8970B mode attention control line ATN false Unless it is set to Talk Only the Noise Figure Meter receives data messages when addressed to listen Virtually all instrument operations available in local mode can be performed in remote mode via data mes sages The major exceptions are changing the LINE switch setting using the Talk Only capa bility and changing the HP IB address of the Noise Figure Meter refer to Table 3 4 3 20 Receiving the Data Message Depending on the status of Special Function 4 the Noise Figure Meter can either talk only or talk and listen both normal operation The instru ment responds to Data messages when it is en abled to remote REN control line true and it is addressed to listen The instrument remains addressed to listen until it receives an Abort mes sage or until its talk add
266. ew Noise Figure Meter the tables will contain the following default information The frequency points will be 10 100 1000 through 26000 every 1000 MHz and 26500 MHz There won t be any default fre quencies after the thirty first 31 table entry The ENR value will be 15 20 dB for each frequency point Setting the ENR Source Identifier NOTE The ENR source identifier is a unique number used to identify the Noise Source associated with one of the stored ENR tables The ENR source identifier should be set before the ENR data is entered into the table If a 3 87 Operation Procedure cont d 3 88 HP 8970B ENR Table Entry conta table other than Table 0 is to be edited that table will have to be recalled into Table 0 before the table can be edited ENR editing is always done to Table 0 To recall a table key in the following sequence RECALL ENR X X is the number of the table 1 4 to be recalled Rel will appear in the INSERTION GAIN display and Enr will appear in the NOISE FIG URE display After the table number is keyed in the displays return to what they were displaying before the recall 1 Press 5 5 SPECIAL FUNCTION A five digit number will appear in the left display if the number is less than five digits leading zeros will be added to the number In either case five digits will be displayed This number is used to identify the Noise Source associated with the ENR table currently in Table 0 The last
267. f Response Status Byte Message Note This check determines if the Noise Figure Meter sends the Status Byte message Before beginning this check press the Noise Figure Meter s PRESET key Then press 4 0 SPECIAL FUNCTION 3 25 Operation HP 8970B OPERATOR S CHECKS HP IB Functional Checks cont d Status Byte Message cont d Operator s Response E HP 85B HP 9000 Series 200 300 Place the Noise Figure Meter in serial poli SPOLL 708 SPOLL 708 mode and address it to talk causing it to send the Status Byte message Check that the controller s display reads 0 Require Service Message Note Operator s Response 3 26 This check determines if the Noise Figure Meter can issue the Require Service message set the SRQ bus control line true This check assumes that the Noise Figure Meter is able to handshake recognize its own address make the remote local changes and receive Data messages Before beginning this check press the Noise Figure Meter s PRESET key Then press 4 0 SPECIAL FUNCTION if an HP 9000 Series 200 300 controller is used a short program is required to perform the last half of this check I HP 858 KP 000 Series 200 300 Send the first part of the Remote message REMOTE 7 REMOTE 7 enabling the Noise Figure Meter to remote Address the Noise Figure Meter to listen OUTPUT 708 OUTPUT 708 lt completing the Remote message then sea send a Data message containing an i
268. f data is read over the Hewlett Packard Interface Bus from the Noise Figure Meter when Special Function 5 6 HP IB code NS is active the Noise Figure Meter will output a special HP IB code for the NOISE FIGURE window For more information about this special HP IB code refer to the Error Messages and Recovery Detailed Operation Instruction Pressing ENTER causes the Noise Figure Meter to resume normal measurement mode The HP IB code to enable ENR table entry is NR The HP IB code for Special Function 5 5 Noise Source identifier is SN The HP IB code for Special Function 5 6 Noise Source catalog is NS The following program is an example of how to download an ENR table into the Noise Figure Meter HP 8970B Comments cont d Related Sections Operation ENR Table Entry conta NOTE This program example was written in BASIC language 3 0 using the HP 9000 Series 200 Model 236 computer 10 20 180 190 200 210 220 DIM Freq 5 40 Enr 5 40 Nfm 708 Address of the Noise Figure Meter N 20 Number for frequency ENR pairs DATA 10 15 20 100 15 40 1000 15 20 2000 15 2 3000 15 00 DATA 4000 15 00 5000 15 10 6000 15 20 7000 15 20 8000 15 30 DATA 9000 15 40 10000 15 50 11000 15 60 12000 15 60 DATA 13000 15 45 14000 15 50 15000 15 35 16000 15 30 DATA 17000 15 30 18000 15 30 T 1 IENR TABLE 1 FOR I 1 TON IFILL UP A TABLE READ Freq T I IREAD FREQUENCY VALUE READ Enr T IREAD ENR VALUE NEXT OUTPUT Nim N
269. f frequency points allowed in a sweep is 181 If the last step of a sweep causes the frequency to exceed the programmed stop fre quency the Noise Figure Meter tunes a partial step to reach the programmed stop frequency HP IB code W2 single sweep should be the last code given before a single sweep is triggered Calibrate Measurement Modes 1 0 through 1 9 3 261 Operation Description 3 262 HP 8970B System Interface Bus Control Special Functions 45 through 49 The Noise Figure Meter has two JEEE 488 1 connectors the Hewlett Packard Inter face Bus HP IB and System Interface Bus SIB The System Interface Bus is actually an HP IB port that the Noise Figure Meter uses to contro such instruments as the system local oscillator a plotter and the Noise Figure Test Set All instruments that the Noise Figure Meter can control are connected to the SIB connector The external computer used to control the Noise Figure Meter is connected to the HP IB connector Also connected to the HP IB connector are any other instruments that the external computer needs to control such as the user controlled local oscillator or other HP IB devices When an instrument is connected to the SIB a special function is used to enable or disable the Noise Figure Meter from sending that instruments commands on the SIB Special Functions 45 through 47 are used to control the HP 8971B Noise Figure Test Set Special Function 45 system local oscilla
270. f the Abort message is received or if the Noise Figure Meter is unad dressed to talk Nonvolatile error messages are INTERRUPT ON SRO READ STATUS BYTE FROM HP 8970B SRQ FROM HP 89708 HP 89708 SRQ DUE TO DATA READY READ DATA FROM HP 89708 RETURN Figure 3 12 Example Flow Chart for Driving the Noise Figure Meter Using the Require Service Message SRQ 3 43 Operation Clearing the Status Byte cont d also cleared when the Status Byte message is sent Thus some error messages that may have caused the Require Service Message to be issued disap pear when a serial poll is performed Refer to the Error Messages and Recovery Detailed Operating Instructions for a listing of volatile and nonvola tile errors Regardless of whether or not the Status Byte message has been sent the Status Byte and any Require Service message pending will be cleared if a Clear message is received 3 44 HP 8970B 3 33 Sending the Status Bit Message The Noise Figure Meter does not respond to a Parallel Poll Enable PPE bus command and thus cannot send the Status Bit message 3 34 Receiving the Abort Message The Abort message is the means by which the con troller sets the Interface Clear IFC bus control line true When the Abort message is received the Noise Figure Meter becomes unaddressed and stops talking or listening HP 8970B Operation zi HP IB SYNTAX AND CHARACTERISTICS SUMMARY Address Se
271. for both the calibration and measurement pamana COLE aaam Function JETESE Data same Function p CI ee O 0000 e3 oin OOO Qa Dow s ASSON RIOOME OEL TEE ot jes Function a pea Function Code Code Function Data Data Function Code e To calibrate the Noise Figure Meter set up the equipment as shown below LOCAL keystrokes HP 89708 l SYSTEM NOISE FIGURE METER LOCAL OSCILLATOR LO OUTPUT NOISE SOURCE FILTER sif A PREAMPLIFIER fS NEEDED DURING THE MEASUREMENT IY MUST BE USED DURING CALIBRATION f Calibrate the equipment in Measurement Mode 1 2 by pressing CALIBRATE twice or sending HP IB code CA 3 142 HP 8970B Operation Measurement Mode 1 2 cont a Special Function 1 2 Example g To make the measurement set up the equipment as shown below cont d HP 89708 SYSTEM NOISE FIGURE METER LOCAL OSCILLATOR LO OUTPUT PREAMPLIFIER IF NEEDED FILTER MIXER h Press CORRECTED NOISE FIGURE AND GAIN or send HP IB code M2 i Press SINGLE or send HP IB code W2 The Noise Figure Meter will sweep from 1500 to 500 MHz in 20 MHz steps but will display the microwave measurement fre quency of 3500 to 4500 MHz After the single sweep is completed the instrument halts Program The HP IB code for Measurement Mode 1 2 is E2 or 1 2SP Codes indications The left display shows each frequency at which a measurement is made and the EX
272. g Calibration will be done at the factory and needs to be done when the Noise Figure Measurement System is first configured and the system local oscillator is a freerunning source or repairs are done to the Noise Figure Test Set NOTE Sweepers are not recommended as the system local oscillator when the Noise Figure Test Set is operating in band SSB3 High local oscillator accuracy is needed by the Noise Figure Measurement System in this band A better choice is a local oscillator that is a synthesizer The Coarse Tuning Calibration will align the passbands of the Noise Figure Meter and Noise Figure Test Set at the following frequencies 2401 MHz 3000 MHz and every 500 MHz from 3500 MHz to 18000 MHz At each of these frequencies the Noise Figure Test Set preselector YIG filter is peaked at the frequency being calibrated The entire calibration procedure will take about 15 minutes The Coarse Tuning Calibration is not needed each time the Noise Figure Measurement System is powered up Normally the Coarse Tuning Calibration will only need to be done once or twice in the lifetime of a Noise Figure Test Set The results of the Coarse Tuning Calibration will be saved in memory in the Noise Figure Test Set Special Function 64 0 is used to enable a Coarse Tuning Calibration The upper fre quency limit of the Noise Figure Test Set can be changed using Special Function 64 1 The allowable range for Special Function 64 1 is 2400 to 30000 MHz Special F
273. gh 16 the Noise Figure Measurement System is operating properly and this check is complete If the system did not operate as indicated go to step 17 Disconnect the Noise Figure Test Set from the Noise Figure Meter s SIB connector If the Operator s Checks for the Noise Figure Meter have not been performed perform the Operator s Checks for the Noise Figure Meter a check for the System Local Oscillator is included The Operator s Checks begin at paragraph 3 10 in this manual Ifthe Noise Figure Meter and System Local Oscillator are found to be operating properly go to step 19 If either of the instruments is not operating properly refer to the appropriate service manual With both the Noise Figure Meter and System Local Oscillator operating properly the following check should be completed before it is assumed that the Noise Figure Test Set is not operating properly Disconnect all instruments from the Noise Figure Meter s HP IB and SIB connectors This test will verify that both buses are operating properly Press 45 2 SPECIAL FUNCTION and 46 1 SPECIAL FUNCTION Turn the Noise Figure Meter off and then back on When Fr CAL is gone from the Noise Figure Meter s display connect the SIB connector to the HP IB connector Press 98 1 SPECIAL FUNCTION SIB tESt is displayed and there is a five second delay before the test begins The results of the test will be displayed on the front panel using one of the error codes
274. gnal generator output power to give a reading of 55 dBm on the power meter 4 20 HP 8970B Performance Tests PERFORMANCE TESTS SPURIOUS RESPONSE PERFORMANCE TEST cont d Procedure 7 contd 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Connect the input of the directional coupler to the INPUT connector of the Noise Figure Meter then press NOISE FIGURE Note the noise figure reading with the signal generator power off dB Note the noise figure reading with the signal generator power on dB Subtract step 9 from step 8 The difference should be less than 0 03 dB dB On the Noise Figure Meter set FREQUENCY to 1400 MHz Note the noise figure reading with the signa generator power off dB Note the noise figure reading with the signal generator power on dB Subtract step 13 from step 12 The difference should be less than 0 03 dB dB Set the signal generator frequency to 1420 MHz Note the noise figure reading with the signal generator power off dB Note the noise figure reading with the signal generator power on dB Subtract step 17 from step 16 The difference should be less than 0 03 dB dB Set the signal generator frequency to 2050 MHz Repeat steps 4 through 7 Note the noise figure reading with the signal generator power off dB Note the noise figure reading with the signal generator power on dB Subtract step 21 from step 2
275. grammed via HP IB A quick test of the Noise Figure Meter s HP IB interface is described earlier in this section under Remote Operator s Checks These checks verify that the Noise Figure Meter can respond to or send each of the applicable bus messages described in Table 3 3 3 15 HP IB Compatibility The Noise Figure Meter has an open collector TTL HP IB interface which can be used with any HP IB computing controller or computer for auto matic system applications The Noise Figure Meter is programmable via the HP Interface Bus Its programming capability is described by the twelve HP IB messages listed in Table 3 3 The Noise Figure Meter s compatibility with HP IB is further defined by the following list of interface functions SH1 AH1 T5 TEO L4 LEO SR1 RL1 PPO DC1 DT1 CO and El A more detailed explanation of these compatibility codes can be found in IEEE Standard 488 1978 and the identical ANSI Stand ard MCi 1 For more information about HP IB refer to the Hewlett Packard Electronic Instru ments and Systems catalog and the booklet titled Improving Measurements in Engineering and Manufacturing HP part number 5952 0058 3 16 Remote Mode Remote Capability The Noise Figure Meter com municates on the bus in both remote and local modes In remote most of the Noise Figure Meter s Operation front panel controls are disabled except for the LINE switch and LOCAL key However front panel display
276. gs Attenuator 10 dB oc scicecin cs iaciens cans HP 8491A Option 010 Power Meter dai ape ai lattotnee gakwioae HP 436A Power Sensor cccccccececeeceneees HP 8484A Signal Generator e cece eee ee HP 8340B SWR Bridge sis siaces vtevensas un wawalues Wiltron 60N50 SIGNAL GENERATOR HP 89708 NOISE FIGURE METER POWER METER STEP 5 Ram f STEP POWER SENSOR Lad STEP 4 10 dB SWR Figure 4 1 Input SWR Test Setup 1 Connect equipment as shown in Figure 4 1 Note that the power sensor is connected to the test port of the SWR bridge 2 Set the Signal Generator for a 10 MHz continuous wave output Set the Signal Generator power level to 23 dBm at the test port of the SWR bridge as read on the power meter Signal Generator power should be approximately 6 dBm 3 On the Noise Figure Meter key in 0 0 SPECIAL FUNCTION to initialize most Special Functions and 60 1 SPECIAL FUNCTION to set the input gain to 20 dB 4 Tune the Signal Generator to 1600 MHz Connect the power sensor to the reflected output port of the SWR bridge Set a relative reference on the power meter 5 Connect the test port of the SWR bridge to the Noise Figure Meter INPUT Slowly tune the Signal Generator in 10 MHz steps down in frequency to 10 MHz While tuning note each frequency at which the power meter reading peaks at less than 12 5 dB below the 0 dB reference set in step 4 For example if the power meter display showed 11
277. gt Indications Related Sections 3 66 HP 8970B Calibration Frequency conta Special Function 31 amp 2 E gan Sao aS Be Z a Ee D ss oe es Bx oo amp Q 4 gt a a c L We Spey pe Function Tle asi k 2g ZE S s PER E 2 22 58 gT 36 SS se SE an SSe ao I Description md amp As i en i 7a Automatic Frequency YO or On On On Calibration 31 0SP Disable Frequency 31 1 Ylor Off Off Off Calibration 31 1SP 31 2 Y2or 31 2SP Off Off 1Table categories are explained in the Special Functions Detailed Operating Instruction Perform One Fre quency Calibration To select the Disable Frequency Calibration Mode LOCAL pomum E omm yama FUNCTION me keystrokes G TD ee EB Gi CEB program codes For HP IB codes refer to Procedure above The INSERTION GAIN and NOISE FIGURE displays are not affected by 31 0 and 31 1 If 31 2 is entered the INSERTION GAIN display shows Fr and NOISE FIGURE display shows CAL until the frequency calibration is completed Calibrate Preset Conditions and Power Up Sequence Special Functions HP 8970B Operation Calibration IF Attenuators Special Function 33 1 READ THE FOLLOWING NOTE BEFORE CALIBRATING THE IF ATTENUATORS USING SPECIAL FUNCTION 33 1 NOTE Using Special Function 33 1 to calibrate the IF attenuators will re duce the gain instrumentation uncertainty specification
278. he fuse are matched to the power source Refer to Figure 2 1 Line Voltage and Fuse Selection Fuses may be ordered under HP part numbers 2110 0043 1 5A 250V normal blow for 100 120 Vac operation and 2110 0001 1 0A 250V normal blow for 220 240 Vac operation 2 6 Power Cables BEFORE CONNECTING THIS INSTRU MENT the protective earth terminals of this instrument must be connected to the protective conductor of the Mains power cord The Mains plug shall only be inserted in a socket outlet provided with a protective earth contact The pro tective action must not be negated by the use of an extension cord power cable without a protective conductor grounding 2 1 Installation Operating voltage is shown in module window SELECTION OF OPERATING VOLTAGE Open cover door pull the FUSE PULL lever and rotate to left Remove the fuse Remove the Line Voltage Selection Card Position the card so the line voltage appears at top left corner Push the card firmly into the stot Rotate the FUSE PULL lever to its normal position insert a fuse of the correct value in the holder Close the cover door To avoid the possibility of hazardous electri cal shock do not operate this instrument at line voltages greater than 126 5 Vac with line frequencies greater than 66 Hz leakage cur rents at these line settings may exceed 3 5 mA Figure 2 1 Line Voltage and Fuse Selection 220 240V OPERATION 220 240V
279. he difference between the Noise Figure Test Set input frequency and the system local oscillator frequency is a fixed value of 450 MHz set by the Noise Figure Measurement System The IF can be changed using Special Function 19 3 For more information on Special Function 19 3 refer to the Fixed IF or LO Frequency Selection Detailed Operating Instruction Normally thereis no reason to change Special Function 19 3 b Special Function 17 1 selects double sideband operation for the Noise Figure Measurement System when the Noise Figure Test Set input frequency is greater than 2400 MHz The measured result is an average of the noise figure at two frequencies the system local oscillator plus the IF into the Noise Figure Meter and the system local oscillator minus the IF into the Noise Figure Meter The IF the difference between the Noise Figure Test Set input frequency and the system local oscillator frequency is a fixed value of 25 MHz set by the Noise Figure Measurement System The IF can be changed using Special Function 19 4 For more information on Special Function 19 4 refer to the Fixed IF or LO Frequency Selection Detailed Operating Instruction Normally there is no need to change Special Function 19 4 c Special Function 17 2 is used with Special Function 17 0 Special Function 17 0 selects single sideband operation for the Noise Figure Measurement System Special 3 227 Operation HP 8970B Sideband Selection conta Special Fu
280. he instrument can accept temperature data entries in three different measurement units Kelvins K Fahrenheit F or Celsius C To select a temperature unit key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Special Function Program Code Description Code HP IB 2 K 11 0 DOor11 0SP C 11 1 Dior1l1 1SP oF 11 2 D2ori1 2SP Table categories are explained in the Special Functions Detailed Operating Instruction tinuous Memory Special Function 0 0 Conditions Clear Conditions Special Function Preset and HP IB 0 9 Conditions E pe amp fla e a aw Can be Stored and Recalled Function Key Stored in Con It is not necessary to select temperature units each time temperature data is entered Once a temperature unit has been selected all temperature data are entered and displayed in the same unit until that unit is changed either by Special Function 0 9 PRESET Special Function 0 0 or by another temperature unit selection After a temperature unit has been selected one of the special functions listed below must be active before temperature data can be entered Special Range of Values Description Function m Enter and Use Thot 0 to 14824 273 2 to 14551 459 7 to 26224 Enter Too 0 to 9999 273 2 to 9725 9 459 7 to 17539 Enter Temperature 0 to 9999 273 2 to 9725 9 459 7 to 17539 of Losses Next key in a value for temperat
281. he left display The decimal value of the cont d factory set addresses are as shown below e Noise Figure Meter 8 e Plotter 5 Pass Control Address 16 System Interface Bus 8 System Local Oscillator 19 Pass Through Device There isn t e Noise Figure Test Set 10 any factory set address A list of allowable addresses is given below ASCII Address Codes Decimal LISTEN TALK Equivalents tom ORAT OOo mH cn kh WN KR On Se re NK MECH MO WOWO ZZ OA MODs OOWP gt r VA 3 114 HP 8970B Operation HP IB and System Interface Bus SIB Addresses contd Special Function 40 Procedure To display the current HP IB or SIB address key in the corresponding Special Function code and then press the SPECIAL FUNCTION key To change an HP IB or SIB address first display the current address Then enter a decimal number from 0 to 30 for the new address and press the ENTER key z p 5 2s Be Ee B21 S21 e sx 9 52 Z 82 82 Specia Function Propam as e SB SB e5 s Code 231 21 25 2 S 28 Noise Figure Meter 40 0 None N Y N NC NC 8 HP IB Address System LO SIB 40 1 EA or N Y N NC NC 19 Address 40 1SP Noise Figure Test 40 2 HT or N Y N NC NC 10 Set SIB Address 40 2SP Plotter SIB Address 40 3 HP or N Y N NC NC 5 40 3SP System Interface 40 4 HS or N Y N NC NC 8 Bus Address 40 4SP Pass Control SIB 40 5 HC or N Y N NC NC 16 Address 40 58P Pass Through Device 40 6 PT or N Y N NC NC NC SIB Address
282. he table after it was recalled The MHz annunciator in the left display will be blinking This indicates that the frequency can be changed if desired To change the frequency key in the new frequency and press ENTER The new frequency will appear as it is typed If an error is made before ENTER is pressed press NOISE FIGURE This will return the original frequency to the display The new frequency can then be re entered If an error was made after ENTER was pressed press DOWN ARROW and then UP ARROW The MHz annunciator in the left display will begin blinking indicating that the frequency can be changed If the default frequency is being used press ENTER In either case pressing ENTER will cause the dB annunciator in the INSERTION GAIN display to begin blinking The blinking dB annunciator indicates that the ENR value can be changed if desired To change the ENR value key in the new value and press ENTER The new ENR value will appear as it is typed With one exception the error recovery procedure is the same as that described for frequency in step 3 If the error is made after ENTER is pressed press DOWN ARROW and ENTER Then re enter the ENR value If the default ENR value is being used press ENTER In either case pressing ENTER will cause the MHz annunciator in the left display to begin blinking and the next entry in the table will be displayed Once the frequency and the ENR value have been entered the ENR table entry number in th
283. her UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements In addition the measurement results for each mode can be displayed on an oscilloscope or output to either a recorder or plotter For explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instructions The following minimum requirements are necessary for the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator to operate in Measurement Mode 1 5 a Thesystem local oscillator and the Noise Figure Test Set must be connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 must be active Noise Figure Meter is System controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 45 0 must be active Noise Figure Test Set enabled in measure ment modes 1 5 through 1 9 Special Function 45 0 is the default setting after using Special Function 0 9 or Special Function 45 1 Noise Figure Test Set enabled always must be active d The address of the Noise Figure Test Set must match the Noise Figure Test Set address that is stored in the Noise Figure Meter Use Special Function 40 2 Noise Figure Test Set System Interface Bus address to display and cha
284. his special function e Special Function 30 0 free run should be active HP IB code is TO f The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes g Set up for a calibration with the device under test DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction h Send the command RM 2EN RS CA Wait for a serial poll to return a non zero value indicating calibration is complete i Insert the DUT into the measurement system j Special Function 30 1 trigger hold must be active HP IB code T1 k Set the Noise Figure Meter s SINGLE sweep on HP IB code is W2 or AUTO sweep on HP IB code is W1 8 153 Operation Comments cont d Related Sections 3 154 HP 8970B Measurement Mode 1 4 cont d Special Function 1 4 1 Set the system local oscillator to the desired frequency Refer to the local oscil lator s operating manual for the required HP IB codes Allow sufficient time for the output of the system local oscillator to stabilize m Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for Special Function 30 2 as it will reset the sweep n Amethod must be determined when to step to a new frequency and read the noise figure results
285. ial Function 30 Since activating the next special function requires fewer keystrokes that is the method used in the example shown in this instruction 2 The device under test DUT must first be connected to the measurement system and the proper RF attenuation level determined The RF attenuators must then be held fixed Special Function 62 for the entire manual measurement 3 The IF attenuators must be held fixed Special Function 72 during the two measurement readings noise source off and on and again during the two calibration readings noise source off and on However the IF attenuators must be allowed to autorange when switching between calibration and measurements and vice versa Procedure To measure calibrate or display manual measurements key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Special Function Program Code Description CI Make cold measure ments source off Make hot measure ments source on Perform cold calibra tion source off Perform hot calibra tion source on Normal display mode Display manual meas urement results Lights Special Function Key Stored in Con tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP 18 Clear Conditions Special Function 0 9 Conditions Table categories are explained in the Special Functions Detailed Operating Instruction 3 121 Operation Example 3
286. ide multipiy square root HP 41C Programmable Attenuator Fixed 10 dB 2 required Attenuator Fixed 20 dB P A HP 85B 82936A C P T ROM Drawer 00085 15005 Advanced Programming ROM or HP 9000 Series 200 or 300 Controller HP IB HP IB compatibility as defined by IEEE Standard 488 and the identical ANSI Standard MC1 1 SH1 AH1 T2 TEO L2 LEO SRO RLO PPO DCO DTO C1 2 3 4 5 Digital Voltmeter DC Voltage Range Up to 100V Resolution in high resolution mode 1 uV on 1 Vdc range Accuracy in high resolution mode 0 003 of reading 4 counts Single Trigger capability Directional Frequency Range 1380 to 2300 MHz HP 778D P Coupler X Y and Z capability Bandwidth 5 MHz Vertical and horizontal full scale deflection 0 10 volts Filter Low Pass Insertion Loss lt 1 dB below 0 9 times cut off HP 360B P A frequency Cut Off Frequency 1200 MHz Rejection gt 50 dB at 1 25 times cut off frequency Frequency Range 10 to 4000 MHz HP 5340A or A Counter Resolution 1 kHz HP 5343A Interface HP IB Required for HP 85B only HP 82937A C Operator s Checks P Performance Tests A Adjustments T Troubleshooting HP 3455A or HP 3456A Systems DVM Display Module HP 1332A Options 101 and 315 C 1 10 HP 8970B General Information Table 1 5 Recommended Test Equipment 2 of 2 eet Specifications Recommended Madel
287. ied to the instrument while protective covers General Information NOISE FIOURE MET ga HP 8970B OPTION 907 FRONT HANDLE KIT LINE POWER CABLE OPTION 908 OPTION 909 RACK FLANGE KIT RACK FLANGE AND FRONT HANDLE COMBINATION KIT Figure 1 1 HP 89708 Accessories Supplied and Options 907 908 and 909 HP 8970B HP 8970B Genera Information SECTION I GENERAL INFORMATION 1 1 INTRODUCTION HP 8970B operating and service documentation consists of an Operating Manual and a Service Manual These two volumes contain all the infor mation required to install operate test adjust and service the HP 8970B Noise Figure Meter Also contained in the Operating Manual is complete installation and operating information for the HP 8970S Noise Figure Measurement System Figure 1 1 shows the Noise Figure Meter with all of its externally supplied accessories The Operating Manual which is shipped with each instrument has four sections Section I General Information Section II Installation Section III Operation Section IV Performance Tests The Service Manual which is shipped with the instrument as Option 915 or ordered separately has four sections Section V Adjustments Section VI Replaceable Parts Section VII Manual Changes Section VIH Service Additional copies of the Operating Manual or the Service Manual can be ordered separately through your nearest Hewlett Packard office The part numbers are l
288. ificantly reduce its effect on HP 8970B HP 8970B Procedure cont d Operation Preamplifier Selection conta measurement uncertainty For DUTs with noise figure and gain less than 17 dB use 2 or 3 dB for Fam p sys in the Selecting the Preampli fier section e NF yin is the measurement system noise figure that minimizes measurement uncer tainty NFmin is in dB e NFuau is the estimated noise figure of the device under test NFau is in dB Gax is the estimated gain of the device under test Gan is in dB 15 dB is a fixed amount that is subtracted from the total of NF and Gay The value of 15 dB was derived from a number of measurement uncertainty versus measurement system noise figure curves The points at which the curves flattened out were observed The flattened portion of the curve is when changing measure ment system noise figure no longer affects measurement uncertainty Selecting the Preamplifier Once the measurement system noise figure NF min is determined the preamplifier is selected The noise figure of the preamplifier must be less than NF min From the cascade gain equation the following equation is used to determine the preamplifier needed NOTE The terms of the equation were in dB and have been converted to linear terms ratios There are no units associated with the linear terms ratios G a Fao amp sys 1 gi F amp sys Famp Gpreamp is the gain of the preamplifier in li
289. ilable for Hewlett Packard products For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual rg HEWLETT PACKARD HP 8970B NOISE FIGURE METER Before operating the Noise Figure Meter read the following information Recording IF Cal Data Refer to paragraph 2 14 Recording IF Cal Data in Section i of the HP 8970B Operating Manual The IF attenuator data is needed to return the Noise Figure Meter to specified operation should a non volatile memory failure occur Error E 80 For those familiar with the HP 8970A Noise Figure Meter please note The pro cedure for calibrating the F attenuators has changed If E 26 or E 13 should occur refer to the Calibrate IF Attenuator detailed operating instruction in Section Ill of the HP 8970B Operating Manual Maximum input Power The maximum average power level for a CW signal at the RF INPUT connector of the HP 8970B must not exceed 20 dBm 100mW The maximum power for a pulsed signal is also 20 dBm 100mW The HP 8970B may be damaged by voltages exceeding 20 Vdc atthe RF INPUT connector Using the HP 346A Noise Source with the HP 8970S T A preamplifier is required when using the HP 346A Noise Source to calibrate the HP 8970S T system Typically a preamplifier with gt 15 dB of gain and lt 6 dB noise figure will work Without a preamplifier er ror E 19 will result when trying to perform a Y
290. in approximately 4 MHz of center frequency 7 On the Noise Figure Meter key in 14 1 SPECIAL FUNCTION to activate the manual measurement mode and make a cold measurement Key in 14 2 SPECIAL FUNCTION to exit the cold measurement mode and store that value and to make hot measurements Finally key in 15 1 SPECIAL FUNCTION to set the Noise Figure Meter to actively display the ratio of hot to cold values The NOISE FIGURE display should now indicate 0 00 dB 8 Tune the signal generator up and down to find the 3 dB frequencies to within 100 kHz Find the center frequency by summing the 3 dB frequencies and dividing by two The center frequency should be within the limits in the table in step 9 HP 8970B Performance Tests PERFORMANCE TESTS TUNING ACCURACY PERFORMANCE TEST cont d Procedure 9 Repeat steps 5 through 8 for each of the frequencies in the table below cont d Center Frequency MHz Nominal Lower Upper Tuned 3 d8 3 dB Frequency Frequency Frequency 4 3 Performance Tests HP 8970B PERFORMANCE TESTS 4 6 INPUT SWR PERFORMANCE TEST Specification Description Equipment Procedure INPUT SWR reflection coefficient lt 1 7 0 26 50 ohms reference impedance The frequency range of the Noise Figure Meter is scanned for frequencies where the return loss is near specification limits Then each high point is checked individually against the specification This is done for several input gain settin
291. in the measurement system are compared for the different measurement modes The following signal points are covered a The output of the noise source for example the HP 346B b The output of the system LO Measurement Modes 1 1 1 4 and the user controlled LO Measurement Modes 1 6 1 9 c The measurement bandwidth of the Noise Figure Meter Noise Figure Measure ment System as seen looking back into the mixer translated to the frequency range of the system LO Measurement Modes 1 1 1 4 and user controlled LO Measurement Modes 1 6 1 9 d The input to the Noise Figure Meter Noise Figure Test Set The noise source output is the same for all modes For a noise source with a nominal Excess Noise Ratio ENR of 15 2 dB the output is broadband random noise varying between approximately 158 8 dBm Hz when on hot and 174 dBm Hz when off cold The ENR of the noise source varies slightly over the frequency range of 10 to 18000 MHz This variation in power level is compensated for in the Noise Figure Meter using the specific information entered into the ENR tables Refer to the ENR Table Entry Detailed Operating Instruction for additional information on the ENR tables There is no system local oscillator used in Measurement Mode 1 0 The user controlled local oscillator is not used in Measurement Mode 1 5 In Measurement Modes 1 1 and 1 3 the system local oscillator can be swept over any range within a 2000 to 18000 MHz b
292. ion 41 2 HP 8673B C Synthesized Signal Generator Special Function 41 3 HP 8340B 8341B Sweep Oscillator Special Function 41 4 custom local oscillator Special Function 41 5 3 140 Pian er ne HP R070R HP 8970B Requirements cont d Procedure Example Operation Measurement Mode 1 2 conta Special Function 1 2 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or output power Use Special Function 42 to define a new program for other system local oscillators There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement uncer tainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selection Detailed Operating Instruction a Select single sideband offset use either Special Function 2 1 2 2 or 2 3 b Press 1 2SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 2 c Set frequenc
293. ion 42 System Local Oscillator Commands Refer to the Pro gramming the System Local Oscillator Detailed Operating Instruction for additional information on how to modify these programs To select one of the predefined programs key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Special Function Program Code Description Code iz HP 8350B Sweep J0 or 41 0SP Oscillator Program HP 8671B 8672A Synthe sized Signal Generator Program HP 8673B C Synthesized Signal Generator Program HP 8340B 8341B Sweep Oscillator Program Lights Special Function Key Stored in Con tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP IB Clear Conditions 6 9 Conditions Special Function zZ O Z Q J2 or 41 2SP Z OQ zZ Q J3 or 41 35P J4 or 41 4SP J5 or 41 5SP Program Table categories are explained in the Special Functions Detailed Operating Instruction If the HP 8673B Option 008 or HP 8673D Synthesized Signal Generator is used as the system local oscillator the auxiliary commands for the predefined program Special Function 41 3 will need to be modified For additional information refer to the Comments section at the end of this instruction To select the predefined program to control the HP 8671B 8672A LOCAL omens COE commen Function keystrokes 4 EB 3 2 GES Grp p
294. ion 42 0 is used to display and change the auxiliary commands The purpose of the auxiliary commands are to set the system LO to continuous wave CW operation b Special Function 42 1 is used to display and change the CW prefix and suffix The purpose of the prefix and suffix is to correctly format the frequency commands from the Noise Figure Meter to the system LO The format is different for different LOs Frequency data of up to five digits is located between the prefix and suffix The frequency information is determined by the frequency parameters entered into the Noise Figure Meter during the measurement setup and by the measurement mode in which the instrument is operating The custom local oscillator program Special Function 41 5 overrides Special Function 42 1 Refer to Special Function 42 7 c Special Function 42 2 is used to display and change the settling time in ms The purpose of the settling time is to ensure that the Noise Figure Meter waits a sufficient amount of time after issuing the frequency command and the auxiliary commands to allow the system LO output to stabilize d Special Functions 42 3 and 42 4 are used to display and change the minimum and maximum frequencies that the program wil accept These entries are in MHz In most cases they will represent the frequency capability of the system LO However they do not affect the system LO but are only used by the Noise Figure Meter to determine if a requested f
295. iption f HP IB 2 PR a Ys ao ao Disables interpolated measurements in Measurement Modes 1 5 through 1 9 Enables interpolated measurements in Measurement Modes 1 5 through 1 9 1 Table categories are described in the Preset Conditions and Power Up Sequence Detailed Operating Instruction N No Y Yea NC No Change To initiate calibration at the existing SWEEP function settings ame Function om LOCAL keystrokes i gt program codes HP 8970B Program Codes Indications Comments Operation Calibrate contra Includes Special Function 39 CA is the program code for the CALIBRATE key The calibration sequence can not be toggled on and off over the HP IB Instead successive CA codes cause the calibration to be restarted To terminate calibration prior to completion use the Sweep Stop command W0 Refer to the Procedure for other HP IB codes The CALIBRATE LED lights and remains lit until the calibration is complete During frequency calibration the INSERTION GAIN display shows Fr and the NOISE FIGURE display shows CAL During second stage calibration the left display indicates each tuned frequency and the NOISE FIGURE display indicates the noise figure at that frequency The frequency range and step size are controled by the SWEEP keys When calibration is completed the instrument resumes making the measurement that was active when CALIBRATE was pr
296. ise Figure Test Set SIB Address Display and Enter Plotter SIB Address Display and Enter SIB Address Display and Enter Pass Control SIB Address Display and Enter the SIB Address of the Pass Through Device on the SIB Display the Pass Through Address of the Noise Figure Meter System LO Programs HP 8350B Sweep Oscillator HP 8671B 8672A Syn Signal Generator HP 8673B C Syn Signal Generator HP 8340B 8341B Sweep Oscillator Custom Loca Oscillator System LO Commands Auxiliary Commands CW Prefix and Suffix Settling Time in ms Minimum Frequency in MHz Maximum Frequency in MHz System Local Oscillator Power Level Power Prefix and Suffix for Custom Local Oscillator Frequency Prefix and Suffix for Custom Local Oscillator HP IB Data Output Selection NOISE FIGURE Only Frequency left display INSERTION GAIN NOISE FIGURE Frequency Calibration Data GmKBm and Second Stage Temperature are Output over HP IB during Calibration Service Request Disable SRQ Capability clears all enabled conditions Enable Data Ready to cause an SRQ Enable Cal Complete to cause an SRQ Enable HP IB Code Error to cause an SRQ Enable SRQ on the SIB to Cause an SRQ Enable Noise Figure Meter Received Control on the SIB to Cause an SRQ Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code 3 54 HP 8970B Operation Table 3 9 Special Function to HP IB Code 5 of 7 Special Function
297. isted on the title page of this manual Also listed on the title page of this manual be low the manual part number is a microfiche part number This number may be used to order 100 x 150 millimetre 4 x 6 inch microfilm trans parencies of this manual Each microfiche con tains up to 96 photo duplicates of the manual pages The microfiche package also includes the latest Manual Changes supplement as well as all pertinent Service notes 1 2 SPECIFICATIONS Instrument specifications for the Noise Figure Meter are listed in Table 1 1 These specifications are the performance standards or limits against which the instrument is tested Supplemental characteristics are listed in Table 1 2 Supple mental characteristics are not warranted specifi cations but are typical characteristics included as additional information for the user Specifications for the Noise Figure Measurement System are listed in Table 1 3 Supplemental characteristics for the Noise Figure Measurement System are listed in Table 1 4 1 3 SAFETY CONSIDERATIONS This product is a Safety Class I instrument that is provided with a protective earth terminal The Noise Figure Meter and all related documentation should be reviewed for familiarization with safety markings and instructions before operation Refer to the Safety Considerations page found at the beginning of this manual for a summary of the safety information Safety information for instal lation ope
298. isten the Noise Figure Meter returns to front panel control when it re ceives the Local message If the instrument wasin local lockout when the Local message was re ceived front panel control is returned but lockout is not cleared Unless it receives the Clear Lock out Set Local message the Noise Figure Meter will return to local lockout the next time it goes to remote No instrument settings are changed by the transition from remote to local When the Noise Figure Meter goes to local mode the front panel REMOTE annunciator turns off However when the Noise Figure Meter is being addressed whether in remote or local its front panel LISTEN or TALK annunciator lights If the Noise Figure Meter is not in local lockout mode pressing the front panel LOCAL key might interrupt a Data message being sent to the instru ment leaving the instrument in a state unknown to the controller This can be prevented by dis abling the Noise Figure Meter s front panel keys entirely using the Local Lockout message HP 8970B 3 26 Receiving the Local Lockout Message The Local Lockout message is the means by which the controller sends the Local Lockout LLO bus command If in remote the Noise Figure Meter responds to the Local Lockout Message by dis abling the front panel LOCAL key The local lock out mode prevents loss of data or system control due to someone accidentally pressing front panel keys If while in local the Noise Figure Met
299. ister 5 press STORE 5 To recall the stored instrument configuration press aec Cs The Noise Figure Meter can store and recall four 1 through 4 Excess Noise Ratio ENR tables For example to store ENR data to table 3 use the following sequence To recall ENR table 3 use the following sequence press l a or example to store an HP 8970B Operation SWEEP FUNCTIONS Sweep parameters are selected in a Function Data ENTER format For example to set the start frequency to 1000 MHz the stop frequency to 1600 MHz and the step size to 100 MHz r BWEEP o DATA MHz press a Coy Ce be e o Ce Ce 2 fe D The Noise Figure Meter can sweep the selected frequency range once SINGLE or repetitively AUTO The sweep can be terminated by pressing the same key again MEASUREMENT i Tas i HP 8970B8 Connect a noise source to the Noise Figure Meter as shown NOISE FIGURE METER UNCORRECTED Uncorrected Noise Figure l WOISE FIGURE To measure uncorrected noise figure press The Noise Figure Meter is measuring its own noise figure NOISE SOURCE f BEN Calibrate Calibrate measures and stores the measurement system noise characteristic at each frequency for correction of later measurements Set START FREQ STOP FREQ and STEP SIZE parameters To initiate a calibration 6 pres twice Corrected Noise Figure and Gain The Noise Figure Meter must be calibrated before a corrected noi
300. ithmetic Smoothing Smoothing Factor Cold Measurement SOURCE off Hot Measurement SOURCE On Cold Calibration SOURCE Off Hot Calibration SOURCE On Display Current Measurement Display Manual Measurement Results Displays Measurement Frequency in Left Display Displays Input to Noise Figure Meter Modes 1 0 through 1 4 or Input to Noise Figure Test Set Modes 1 5 through 1 9 in Left Display Left Display is Blanked All Displays are Blanked Single Sideband Operation Modes 1 5 through 1 9 Double Sideband Operation Modes 1 5 through 1 9 Upper and Lower Sideband Crossover Frequency Selection Internal IF for SSB2 Internal IF for SSB3 Internal IF for DSB Display Noise Figure Meter Input Frequency HP 8970B Operation Table 3 9 Special Function to HP IB Code 3 of 7 ae Function a ae Functions Plotter Functions Trigger Selection Frequency Calibration Input Gain Calibration IF Attenuators Calibration Loss Compensation Sequence Functions Noise Figure Test Set YIG Filter Fine Tuning Calibration Description Go to Lower Left Go to Upper Right Plot Noise Figure Plot Gain X AXIS Output is Noise Figure and Y AXIS Output is Gain Strip Chart mode Plot Grid and Data Plot Grid and Axes Labels Plot Data Only Select Noise Pen Number Select Gain Pen Number Select Plot Name Free Run Hold Execute Automatic Disable Frequency Cal Perform 1 Frequency Cal 20 10 and 0
301. l controller when in Measurement Mode 1 3 a Press PRESET or send HP IB code PR to establish initial conditions NOTE Measurement Mode 1 3 must be activated prior to entering the frequency parameters to avoid error E35 entered value is out of range b Press 1 3 SPECIAL FUNCTION to activate Measurement Mode 1 3 c Set the frequency parameters for both the calibration and measurement 3 146 HP 8970B Operation Measurement Mode 1 3 contd Special Function 1 3 Example p Code Function Data Function cont d uaa me 1 OOOR 00 OJO Qs OO LOCAL keystrokes E3IF70MZFA3000MZFB4500MZSS20MZ Code E Function Code Data Data Code Be HP 15 5 program codes Function Function Code Data Data Code Function d To calibrate the Noise Figure Meter set up the equipment as shown below HP 89708 NOISE FIGURE METER eif THE PREAMPLIFIER IS USED DURING THE MEASUREMENT PREAMPLIFIER IT MUST BE USED DURING THE CALIBRATION e Calibrate the equipment in Measurement Mode 1 3 by pressing CALIBRATE twice f To make the measurement set up the equipment as shown below HP 89708 SYSTEM NOISE FIGURE METER LOCAL OSCILLATOR LO OUTPUT PREAMPLIFIER iF NEEDED DUT MIXER OR RECEIVER g Press CORRECTED NOISE FIGURE AND GAIN h Press SINGLE The Noise Figure Meter will sweep the system LO from 3 GHz to 4 5 GHz in 20 MHz steps and ha
302. l dsip aq 0 4319 eted daams puana ayy asneo she AFIMS 2 an i 335 suoRIunN petoads Husn uym aiqissod aie sAeidsip 19440 YNF pue usw BINSPBU P31981I09 E JOJ 388 JepUN JAP 94 Jo ueb y sAgidsip NIV NOLLYASNI G 8nBi4 aes sanjea mau 40 Aue y qeus pue peARidsip aq 0 s anjea zuaw u Aou nbal pue Aouenb 944 paun JUBLINO y esnea shox AIY4 FXI s3YNLY34 TENVd LNOWS uoeiodo HP 8970B SIMPLIFIED OPERATION 7 PRESET rae Press Preset This sets the front panel functions to the following FREQUENCY 30 MHz STEP SIZE 20 MHz FREQ INCR 20 MHz SMOOTHING 1 START FREQ 10 MHz MEASUREMENT UNCORRECTED NOISE FIGURE STOP FREQ 1600 MHz CALIBRATE Off SWEEP Off In addition default values are entered for some Special Functions Refer to Table 3 14 Special Function Summary MEASUREMENT MODES The Noise Figure Meter has ten Measurement Modes 1 0 through 1 9 Mode 1 0 is used for RF measurements ranging from 10 to 1600 MHz and requires no external equipment except a noise source Modes 1 1 through 1 4 are used for microwave measurements of up to 99999 MHz and require the system local oscillator LO Modes 1 1 and 1 2 also require an external mixer the mixer is part of the device under test DUT in Modes 1 3 and 1 4 Modes 1 5 through 1 9 are also for microwave measurements Mode 1 5 is used for measurements from 10 to 18000 MHz Modes 1 6 through 1 9 are for measurements up to 999
303. lator frequency does not apply The allowable range of values for the loca oscillator is 10 to 99999 MHz Measurement Modes 1 7 and 1 9 and 0 to 99999 MHz Measurement Modes 1 2 1 4 1 7 and 1 9 Special Function 3 2 is used to display the user controlled local oscillator frequency in Measurement Modes 1 6 through 1 9 Special Function 3 2 is particularly useful in Measurement Modes 1 6 and 1 8 The frequency that the user controlled local oscillator should be set to is displayed If zero is displayed an error exists with the Special Function 3 frequency and Special Function 2 frequency mix Special Functions 19 2 through 19 4 are used when the Noise Figure Test Set is configured with the Noise Figure Meter These special functions are used to change the internal IF between the Noise Figure Meter and the Noise Figure Test Set Special Functions 19 2 through 19 4 can only be used when the measurement frequency is greater than 1601 MHz The default IFs for Special Functions 19 2 through 19 4 have been carefully chosen only small deviations from the defaults should be used and only if the particular measurement requires that the default be changed Special Function 19 5 is used to display the current frequency IF thatis being input to the Noise Figure Meter Front panel frequency entries should be made in integer MHz units If a decimal MHz entry is made the instrument rounds the entry to the nearest integer 0 6 MHz and above are rounded up
304. lay and Enter Internal IF for SSB3 Display and Enter Internal IF for DSB Display Noise Figure Meter Input Frequency Teold Disable Noise Figure Test Set on the System Interface Bus Enable Noise Figure Test Set in Modes 1 5 through 1 9 Thot System LO Settling Time Enable Noise Figure Test Set in Modes 1 0 through 1 9 Trigger Selection Free Run Hold Execute Display User Controlled Local Oscillator Frequency Modes 1 5 through 1 9 1 Step up Go to Upper Right for X Y Recorder Noise Figure Meter YIG Filter Tuning Functions YIG DAC is Updated when Frequency is Changed 0 MHz Hold Off 0 MHz Hold On Voltmeter Mode Noise Source Off Noise Source On Display Pass Through Address of Noise Figure Meter Exponential Smoothing Arithmetic Smoothing Enter Plot Name Sweep Off AUTO Sweep SINGLE Sweep Recorder Test Functions X Axis Test Display Resolution Maximum Resolution Less Resolution on Noise Figure Less Resolution on Gain Recorder Test Functions Y Axis Test Frequency Calibration Automatic Disable Frequency Cal Perform 1 Frequency Cal Disables Debug Oscilloscope Plots Enables Debug Oscilloscope Plots Individual RF Attenuator Selection Select RF Thru Path Select 10 dB Pad No 1 Select 20 dB Input Amplifier Select 10 dB Pad No 2 Select 10 dB Pad No 3 HP 8970B Operation Table 3 9 B ee Function to HP IB Code 1 of 7 Speal Function Function HP I8 Code Description pm wl Initialize Speci
305. le each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements Or the meas urement results for each mode can be displayed on an oscilloscope or output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction The following minimum requirements are necessary for the Noise Figure Measurement System and the user controlled local oscillator to operate in Measurement Mode 1 7 a Thesystem local oscillator and the Noise Figure Test Set must be connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 must be active Noise Figure Meter is system controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 45 0 must be active Noise Figure Test Set enabled in measure ment modes 1 5 through 1 9 Special Function 45 0 is the default setting after using Special Function 0 9 or Special Function 45 1 Noise Figure Test Set enabled always must be active ID aaan HP 8970B Requirements cont d Procedure Operation Measurement Mode 1 7 conta Special Function 1 7 d The address of the Noise Figure Test Set must match the Noise Figure Test Set address that is stored in the Noise
306. lected and displayed on front panel using Special Function 44 0 Noise Figure Meter HP IB Address Factory set to 8 decimal Numeric Data Input Format Except in Voltmeter mode DDDDDEsiNN 5 Digit Signed Mantissa Exponent Magnitude leading decimal not allowed Exponent Sign Indicates Exponent Follows Output Formats Except in Voltmeter mode HP IB code HO 43 0 SP sDDDDDE NNCRLF HP IB code H1 43 1 SP sDDDDDE NN sDDDDDEZNN zDDDDDE NNCRLF and H2 43 2 SP Signed Mantissa indicates Exponent Follows Exponent Sign Exponent Magnitude Carriage Return Line Feed Errors 90DDDE 06CRLF Line Feed Error Code Carriage Return Special HP IB error codes used for ENR Editing ENR Catalog and Noise Figure Test Set Coarse and Fine Tuning Calibration ENR Editing or Catalog 80 TNNE 06 Fixed Data Le Fixed Exponent ENR Table Number ENR Tabie Entry Number or Total Number of Entries in the Table Noise Figure Test Set Coarse or Fine Tuning Calibration BONNNE 06 Fixed Data Fixed Exponent Special Function for a Coarse or Fine Tuning Calibration Reserved Number used for the special display or a blank display S0000E 06CRLF Reserved Number used for the overflow in measurement or measured noise figure gt 32 dB 90099E 06CRLF Return to Local Front panel LOCAL key if not locked out For information on the Voltmeter mode refer to Section VIII Section VI
307. lected measurement When either We or is pressed the tuned frequency is changed in the selected direction The new tuned frequency is displayed in the left display and the instrument continues with the selected measurement Front panel frequency increment values should be entered in integer MHz units If a decimal MHz entry is made the instrument rounds the entry to the nearest integer 0 5 MHz and above is rounded up The Hz unit provided for HP IB is for programmer convenience The instrument rounds all HP IB tuned frequency inputs to the nearest MHz If e or W is pressed rapidly in succession the left display updates the frequency each time the key is pressed The noise measurement may be delayed will appear in the NOISE FIGURE display especially if smoothing is used HP 8970B Comments cont d Related Sections Fixed Frequency Increment conta Operation For highest repeatability always tune in the same manner direction and step size as the calibration was done Fixed Frequency Tuning Measurement Modes 1 0 through 1 9 Preset Conditions and Power Up Sequence 3 107 Operation Description Procedure 3 108 HP 8970B Fixed Frequency Tuning The FREQUENCY key is used to display the frequency to which the instrument is tuned and to enter a new fixed frequency value The allowable frequency range is 10 to 1610 MHz in Measurement Modes 1 0 and 1 4 e 10 to 18000 MHz in Measur
308. lection Measurement Modes Sideband Selection Special Functions HP 8970B Description Requirements Operation Measurement Mode 1 3 Special Function 1 3 Measurement Mode 1 3 provides a means of controlling the system LO to measure a frequency conversion device This mode uses a fixed IF and allows for frequency conversion in the device under test DUT Although the signal measured at the Noise Figure Meter INPUT is always in the range of 10 to 1600 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency However the correct 10 to 1600 MHz ENRis used during calibration Atypical DUTisa mixer or receiver All of the Measurement Modes can be set to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements Or the measurement results for each mode can be displayed on an oscilloscope or output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measure ment Mode and sideband operation refer to the Measurement Modes Detailed Operat ing Instruction The following minimum requirements are necessary for the Noise Figure Meter to act as a controller in Measurement Mode 1 3 a The system local oscillator must be connected to the Noise Figure Meter s SYS TEM INTERFACE BUS connector
309. librated and they use nominal values for noise figure These Special Functions are primarily used to verify that the measurement system is operating i Special Functions 9 1 and 9 2 do not correct for the RF attenuators There can be an error for very low power when the lowest RF attenuation is selected Calibrate Measurement Modes 1 1 through 1 9 Special Functions 3 201 Description Procedure 3 202 Overation Preamplifier Selection Measurement system noise figure directly affects measurement uncertainty as the measurement system noise figure increases measurement uncertainty increases see tem brated o figure i is reduced to a specific level its effect on measurement uncer tainty is minimal The effect of measurement system noise figure on measurement uncertainty can be reduced to this specific level with a preamplifier The preamplifier is placed between the device under test DUT and the measurement system The preampli fier is part of the measurement system when it is calibrated When measuring low noise figure gain devices it may not be possible to mini mize the inaccuracy effect of the meas urement system In these cases it is best to reduce measurement system noise fig ure as much as possible 2 or 3 dB is pos sible and thus reduce its effect on measurement uncertainty This discussion will cover the following topics figure The measurement system is d _ fined as those e comp
310. libration for example from start frequency to stop frequency j Press CORRECTED NOISE FIGURE AND GAIN k Perform a triggered sweep of the user controlled local oscillator and the Noise Figure Measurement System to gather the data The HP IB code for Measurement Mode 1 6 is E6 or 1 6SP Refer to Comments for additional information on using HP IB program codes in Measurement Mode 1 6 The left display shows each frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain of the DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used to control the Noise Figure Measurement System and the user controlled local oscillator The following general conditions must be observed when using an external controller a The external controller and the user controlled local oscillator must be connected to the HP IB connector on the Noise Figure Meter b HP IB code H1 must be active c Special Function 4 0 normal talker and listener must be active Note that there is no HP IB code for this special function d Special Function 30 1 trigger hold must be active HP IB code is TI e The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP I
311. libration or the START FREQ STOP FREQ or STEP SIZE have been changed Fine Tuning Calibration is controlled by Special Functions 36 0 through 36 4 The progress of the Coarse and Fine Tuning Calibrations may be viewed on an analog oscilloscope using Special Functions 97 1 and 97 2 These special functions can be used to diagnose any measurement system setup problems Special Functions 97 1 and 97 2 are described in the Example section of this instruction Refer to Viewing a Coarse or Fine Tuning Calibration on an Oscilloscope The following discussion will help to give a better understanding of Special Functions 36 0 through 36 4 64 0 and 64 1 Special Function 36 0 will enable a Fine Tuning Calibration to be done just before the Noise Figure Measurement System is calibrated when a CORRECTED NOISE FIG URE AND GAIN measurement is to be made Also error twenty eight E28 is _ enabled Possible causes for error twenty eight are given in the Comments section at the end of this instruction Error twenty eight E28 is a warning to the user and is not necessarily an indication of any hardware problem Special Function 36 1 will disable a Fine Tuning Calibration each time the Noise Figure Measurement System is calibrated The user can perform a Fine Tuning Cali bration using Special Function 36 3 Special Function 36 2 disables a Fine Tuning Calibration each time the Noise Figure Measurement System is calibrated and also disables the erro
312. lifier will be used during the measurement the preamplifier must be used during the calibration d Insert DUT and measure e The left display shows the swept IF Example NOTE The following example assumes that the Noise Figure Meter is the controller on the System Interface Bus For information on using an external controller refer to the Comments section at the end of this instruction To make a swept CORRECTED NOISE FIGURE AND GAIN measurement over an IF of 10 MHz to 1 GHz using 20 MHz steps with a fixed system LO frequency of 10 GHz a Press PRESET or send HP IB code PR to establish initial conditions b Set the frequency parameters for both the calibration and measurement 3 151 fir OoOvivDp UWperauvl Measurement Mode 1 4 cont d Special Function 1 4 Example eos 696 COUR amem Function _ eR Data mm Function a D Of wot Doo Ge e OOD Ha ODO keystrokes S FA10MZFB1000MZSS20MZLF10000MZ_ Tas Function lt a Cael ge Function Code program codes Code Function Data Data Function Code c Prete 1 4 SPECIAL FUNCTION or send HP IB code E4 to activate Measurement Mode 1 4 d To calibrate the Noise Figure Meter set up the equipment as shown below HP 89708 NOISE FIGURE METER sif THE PREAMPLIFIER 1S NEEDED FOR THE MEASUREMENT ePREAMPLIF LER 17 MUST BE USED DURING THE CALIBRATION e Calibrate the equipment in Measurement Mode 1 4 by pressing CALIBRATE twice or sending H
313. ll reset the sweep p Amethod must be determined when to step to a new frequency after reading the noise figure results This read operation cannot be completed until the new data is ready It is possible to write an SRQ interrupt routine on the Data Ready Status Bit Refer to Enabling the Service Request Condition paragraph 3 30 q Continue to loop through steps n o and p A method for determining when the measurements are complete must be programmed into the external controller One method is to compare the measurement frequency read from the Noise Figure Meter with the stop frequency programmed into the Noise Figure Meter and terminate the program after the measurement in which they are equal HP 8970R Fir oyub vUperation Measurement Mode 1 6 cont d Special Function 1 6 Related Calibrate Sections Controller Capability of the Noise Figure Meter Fixed IF Selection Measurement Modes Noise Figure Test Set YIG Filter Calibration Sideband Selection Special Functions Trigger Selection 3 167 EIN ONAT m WH PCS MVL Description Requirements 3 168 Drrnavahan hi Uv i yes Measurement Mode 1 7 Special Function 1 7 NOTE A double sideband measurement can not be made when using Measure ment Mode 1 7 Measurement Mode 1 7 requires the use of the HP 8971B Noise Figure Test Set a system local oscillator and a user controlled local oscillator Measurement Mode 1 7 uses two stages of frequency conversi
314. llows tDDDDDEiNNCRLF Signed Mantissa Line Feed Indicates Exponent Follows Carriage Return Exponent Sign Exponent Magnitude A summary of the different data outputs is listed in Table 3 5 When an error is output to the bus it follows the same 12 byte format described above except most of the numeric digits have predetermined values as shown below Error outputs always exceed 90 000 000 000 The two digit error code is represented by the last two digits of the five digit mantissa The error code can be derived from the string by sub tracting 9 x 101 then dividing the result by 1 000 000 3 37 Operation Sending the Data Message cont d Table 3 5 HP IB Data Output Summary Front Panel Display HP IB Output Format Conditions Left Display DDDDDE 06 DDDDDEANN Data other than frequency Frequency 90000E 06 tDDDDDELNN Display is blank INSERTION GAIN Gain or Calibra tion data GmKBm is displayed 90000E 06 Display is blank NOISE FIGURE DDDDDESNN Normal display or second stage temperature DDDDDDE 05 Voltmeter mode 900DDE 06 Error codes where DD is the error code 90000E 06 Data not ready Sent when the instrument receives a read command while 2 is dis played in Trig ger Hold mode Also sent when display is blank The HP IB data output for mode H0 is NOISE FIGURE CR LF The HP IB data output for mode H1 or H2 is Left Display INS
315. lse an error code E34 is displayed The reason a double sideband measurement cannot be made in Modes 1 2 or 1 7 is that the frequency at which the measurement is being made is ambiguous Therefore one of the two single sideband special functions must be selected and the other sideband must be filtered out after the device under test DUT for a meaningful sweep This eliminates any noise thatis added by the DUT that may fall in the undesired sideband Itisin Measurement Modes 1 1 1 3 1 4 1 6 1 8 and 1 9 that the choice between single or double sideband becomes necessary The following brief description will help clarify the choices available a Special Function 2 0 selects a double sideband measurement The measured result is an average of the noise figure at two frequencies in Measurement Modes 1 1 through 1 4 the system local oscillator frequency plus the IF and the system loca oscillator minus the IF in Measurement Modes 1 6 through 1 9 the user controlled local oscillator frequency plus the IF and the user controlled local oscillator frequency minus the IF b Special Function 2 1 offsets the measurement frequency to the system local oscillator frequency minus the IF in Measurement Modes 1 1 through 1 4 Special Function 2 1 offsets the measurement frequency to the user controlled local oscillator frequency minus the IF in Measurement Modes 1 6 through 1 9 The Noise Figure Meter uses the ENR Excess Noise Ratio value of the off
316. lt 3 147 Operation Program Codes Indications Comments 3 148 HP 8970B Measurement Mode 1 3 conta Special Function 1 3 The HP IB code for Measurement Mode 1 3 is E3 or 1 8SP Refer to Comments for additional information on using HP IB program codes in Measurement Mode 1 3 The left display shows each frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain ofthe DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used in place of the Noise Figure Meter to control the system LO and the Noise Figure Meter in Measurement Mode 1 3 The following general conditions must be observed when using an external controller a The system local oscillator and the external controller must be connected to the HP IB connector on the Noise Figure Meter b HP IB code H1 must be active c Special Function 46 1 must be active d Special Function 4 0 normal talker and listener must be active Note that there is no HP IB code for this special function e Special Function 30 0 free run should be active HP IB code is TO f The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes
317. mat CPPPPCSSSS C equals the decimal count character P equals the prefix ASCII characters S equals the suffix ASCII characters Use the front panel to enter the ASCII characters using their decimal equivalents Since the count characters are in decimal they are entered as they are Press ENTER each time a decimal number is keyed in j Press 46 0 SPECIAL FUNCTION This enables the system local oscillator on the System Interface Bus kik OFIUD Uperation Programs Available to Control The System LO Special Function 41 Description Special Function 41 selects predefined programs to control the system LO Special Procedure Example VD anrAD Custom Local Oscillator Function 41 0 selects the program for the HP 8350B Sweep Oscillator Special Function 41 2 selects the program for the HP 8671B 8672A Synthesized Signal Generators Special Function 41 3 selects the program for the HP 8673B C Synthesized Signal Generator Special Function 41 4 selects the program for the HP 8340B 8341B Sweep Oscillator and Special Function 41 5 selects the program for the custom local oscillator A listing of these programs is contained in the Comments section of this instruction The programs are activated when Special Function 46 0 enable system local oscillator on the System Interface Bus a Measurement Mode 1 1 through 1 4 or 1 6 through 1 9 and the correct predefined program has been selected The programs can be modified using Special Funct
318. measurement cont d gunmen COJE amen Function pman 1212 n FUNCTION OOO Qis OOO x wa of O OOOO eystrokes ooon ooo bee Function ix gt Data Code Function Function Data Code Code Data Function program codes d Enter the ENR tables for calibration Special Function 5 7 and the measurement Special Function 5 8 if this hasn t already been done Refer to the ENR Table Entry Detailed Operating Instruction for more information e Press 2 1 SPECIALFUNCTION to select a lower sideband measurement Special Function 2 1 is used to select the sideband operation desired for the first frequency conversion using the user controlled local oscillator and the device under test NOTE When a single sideband measurement is being made the user must place a filter between the noise source and the device under test to eliminate the unwanted sideband f To calibrate the Noise Figure Measurement System and perform a Noise Figure Test Set Fine Tuning Calibration set up the equipment as shown below 3 186 Oe adh aha PY wan de ee HP ga7nR HP 8970B Operation Measurement Mode 1 9 conta Special Function 1 9 Example NOTES cont d For a single sideband measurement the external filter is not included during calibration During calibration the Noise Figure Meter only accounts for loss after the device under test Since the filter is before the device under test the loss of the filter is not accounted f
319. ment Special Function 2 1 is used to select the sideband operation desired for the first frequency conversion using the user controlled local oscillator and the external mixer NOTE When a single sideband measurement is being made the user must place a filter between the device under test and the external mixer to eliminate the unwanted sideband f Configure the user controlled local oscillator to produce a 3 5 GHz IF at the input of the Noise Figure Measurement System The correct frequency to set the user controlled local oscillator to can be viewed by using Special Function 3 2 puts COC cmmmemen Function grinn 1a uso Function GIG Bit QMO eji separ Er a 9 Foci oo oaa amim CIMA e GD CIC amp E6B 1IFS3S500MZFA20000MZFB24000MZSS200MZ Code L Function al Code Data Code Code Data Function Function Data Code Code Data Function program codes g To calibrate the Noise Figure Measurement System and perform a Noise Figure Test Set Fine Tuning Calibration set up the equipment as shown below 3 163 Operation Example cont d 3 164 HP 8970B Measurement Mode 1 6 conta Special Function 1 6 HP 8971B NOISE FIGURE TEST SET SYSTEM LOCAL OSCILLATOR IF OUTPUT NOISE SOURCE DRIVE OUTPUT NO ISE PREAMPLIFIER FILTER SOURCE elF THE PREAMPLIFIER AND FILTER ARE NEEDED DURING THE MEASUREMENT THE FILTER iS ADDED IF A SINGLE SIDEBAND MEASUREMENT I BEING MA
320. ments specified under Requirements are satisfied Refer to Comments for a brief description of using an external controller when in Measurement Mode 1 8 a Press PRESET or send HP IB code PR to establish initial conditions PRESET selects a single sideband measurement Special Function 17 0 for the Noise Figure Test Set NOTE Measurement Mode 1 8 must be activated prior to entering the fre quency parameters to avoid error E35 entered value is out of range b Press 1 8 SPECIAL FUNCTION to activate Measurement Mode 1 8 3 178 HP 8970B Operation Measurement Mode 1 8 conta Special Function 1 8 Example c Set the frequency parameters for both the calibration and measurement cont d yee Code ammm FUNCTION jerome Dat aaan Oo ao LOCAL BOQ kits keystrokes C C Co C oomo oloo oopa OOO E8BiiF4000MZFAS0000MZFB45000MZSS2Z00MZ Code e unetan Code Data L HP IB d Code Code program codes Data Function Function Data Code Code Data Function d Enter the calibration and measurement ENR tables if this hasn t already been done Special Functions 5 7 and 5 8 e Press 2 1 SPECIAL FUNCTION to enable a lower sideband measurement Spe cial Function 2 1 is used with the first frequency conversion using the user controlled local oscillator and the device under test NOTE When a single sideband measurement is being made the user must place a filter between the noise source and the device unde
321. mes sage when data is ready This subroutine structure frees the controller to process other routines until the Noise Figure Meter is ready with data 3 31 Sending the Status Byte Message After receiving a Serial Poll Enable bus command SPE and when addressed to talk the Noise Figure Meter sends a Status Byte message The Status Byte message consists of one 8 bit byte in which 7 of the bits are set according to the enabled conditions described above under Sending the Require Service Message If one or more of the seven conditions are enabled and present all the bits corresponding to the conditions and also bit 6 the RQS bit will be set true and the Require Ser vice message is sent If one of the above condi tions occurs but has not been enabled by Special Function 44 or the HP IB codes neither the bit corresponding to the condition nor the RQS bit will be set and the Require Service message will not be sent The bit pattern of the Status Byte is shown in the HP IB Syntax and Characteristics Summary Extended Status Byte A second status byteis avail able but can only be accessed via the Output Status function refer to the following paragraph for an explanation of the Output Status function Bit 7 of the Status Byte indicates that an enabled condition on the Extended Status Byte is true If Bit 7 is true the second status byte should be accessed via the Output Status function to determine what caused Bit 7 to become tru
322. minimum requirements are necessary for the Noise Figure Meter to act as a controller in Measurement Mode 1 1 a Connect the system local oscillator to the Noise Figure Meter s SYSTEM INTER FACE BUS connector with an HP IB cable b Special Function 48 0 active Noise Figure Meter is the controller on System Inter face Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 46 0 active Enable system local oscillator on the System Inter face Bus Special Function 46 0 is the default setting after using Special Function 0 9 d The address of the system LO must match the system LO address that is stored in the Noise Figure Meter Use Special Function 40 1 system LO address to display and change this address if necessary The default address is 19 after using Special Func tion 0 9 e The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below o HP 8350B Sweep Oscillator Special Function 41 0 e HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 HP 8673B C Synthesized Signal Generator Special Function 41 3 HP 8340B 8341B Sweep Oscillator Special Function 41 4 custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters f
323. mum vertical limit for noise figure When pressed the current NOISE MIN vaiue appears in the left display The allowable range of values for NOISE MIN is 9999 dB to 99999 dB This key performs the same function as Special Function 8 1 Figure 3 3 GAIN MAX GAIN MIN NOISE MAX and NOISE MIN Features Operation E PRESET Key Returns the instrument to a known state Refer to the Preset Conditions and Power Up Sequence Detailed Operating Instruction for a list of preset conditions and default values 3 LINE Switch Applies power to the Noise Figure Meter when set to the ON position 3 ENR Key Used to display and enable entry of the excess noise ratio ENR versus frequency tables Five ENR tables each table containing 35 frequen cies can be entered into the Noise Figure Meter Frequency is shown in the left display and the corresponding ENR is shown in the INSERTION GAIN HP 8970B BOURCE Se display The NOISE FIGURE display shows the ENR table number 0 4 and the current table entry number 1 through 35 An ENR table is selected by using the following sequence RECALL ENR N Nis the number of the ENR table being recalled An ENR table is stored using the following sequence STORE ENR N N is the number of the ENR table being stored C NOISE SOURCE DRIVE OUTPUT This BNC connector provides the output to drive a noise source on and off with 28 volt pulses Figure 3 4 LINE Switch PRESET and SOURCE Features 3
324. n Description 3 110 HP 8970B Fixed IF or LO Frequency Selection Special Functions 3 and 19 Specia Function 3 displays and allows entry of the fixed IF and LO frequencies This special function is used when the measurement signal is down converted prior to being input to the Noise Figure Meter Measurement Modes 1 1 through 1 4 or the Noise Figure Test Set Measurement Modes 1 6 through 1 9 Special Function 19 is ONLY used in Measurement Modes 1 5 through 1 9 Special Function 19 displays and allows the user to change the internal IF between the Noise Figure Meter and the Noise Figure Test Set The internal IF can only be changed when the measurement frequency is between 1601 and 18000 MHz Special Function 3 0 is used to display and enter the fixed IF for Measurement Modes 1 1 1 3 1 6 and 1 8 If no entry is made the Noise Figure Meter uses the last entered value The fixed IF value does not apply when the instrument is operated in Measurement Modes 1 0 1 2 1 4 1 5 1 7 or 1 9 The allowable range of values for IF entries is 10 to 1600 MHz Measurement Modes 1 1 and 1 3 or 10 to 18000 MHz Measurement Modes 1 6 and 1 8 Special Function 3 1 is used to display and enter the fixed local oscillator frequency for Measurement Modes 1 2 1 4 1 7 and 1 9 If no entry is made the Noise Figure Meter uses the last entered value If the instrument is operated in Measurement Modes 1 0 1 1 1 3 1 5 1 6 or 1 8 the fixed local oscil
325. n 97 1 sets the maximum limit to 500 and the minimum limit to 120 3 196 24h We FUE Example contd Program Codes a gt indications Comments Related Sections HP 2a7nR WFpCcrlaruivull Noise Figure Test Set YIG Filter Calibration contd Special Functions 36 and 64 To change the maximum limit and minimum limit use the front panel keys of GAIN MAX Special Function 8 4 and GAIN MIN Special Function 8 3 The limits are entered by pressing the appropriate key keying in the data and pressing ENTER e When finished viewing the Coarse or Fine Tuning Calibration press 97 2 SPE CIAL FUNCTION or send HP IB code Y8 Special Function 97 2 disables the oscillo scope from displaying the Coarse or Fine Tuning Calibration and restores the GAIN MIN and GAIN MAX settings to where they were before Special Function 97 1 was enabled For HP IB codes refer to the Procedure above For a Coarse and Fine Tuning Calibration the left display shows each Noise Figure Test Set input frequency at which a calibration is made The INSERTION GAIN display shows 8971 The NOISE FIGURE display shows CAL When viewing a Coarse Tuning Calibration a noise peak will be drawn on the oscillo scope for each frequency point being coarse tuned When viewing a Fine Tuning Calibration a first pass at finding the noise peak is drawn and then a reference power line is drawn Finally a dot is placed where the actual noise peak
326. n Section VIII Service Refer to Service Related Errors in Section VIII Service Section VHI Service ig in the Service Manual The part number of the Service Manual is on the title page of this manual 3 95 Operation Error Messages cont d 3 96 HP 89705 Error Messages and Recovery cont Error Volatile V or Nonvolatile NV Recommended Action Comments Hardware Error contd Refer to Service Related Errors in Section VII Service Frequency calibration failed Noise Figure Test Set YIG Filter calibration coarse or fine failed Refer to the Comments section at the end of this instruction Not Properly Calibrated For Corrected Measurement General Remedy Repeat calibration NV Not calibrated Perform calibration prior to select ing CORRECTED NOISE FIGURE AND GAIN measurement Current frequency is out of Select frequency within calibrated calibrated range or not a range calibrate over a new fre calibrated point in Modes quency range or refer to Special 1 5 1 9 Function 39 in Modes 1 5 1 9 Current RF attenuation not Select appropriate input gain calibrated calibration range Special Function 32 Not calibrated in the current Perform calibration in current measurement and sideband measurement and sideband modes modes NV Not calibrated for the Perform calibration Changing current IF Measurement a
327. n for the current set of frequencies defined by START FREQ STOP FREQ and STEP SIZE The calibration can be performed using Special Function 36 3 Ifa point between those defined by START FREQ STOP FREQ and STEP SIZE needs to be fine tuned Special Function 36 4 can be used The error could have been generated due to the following reasons The YIG filter in the Noise Figure Test Set has not been fine tuned at the current frequency and coarse tune data is being used o The current frequency of the Noise Figure Test Set YIG filter has been interpolated from the fine tuning calibration data The Noise Figure Test Set has been fine tuned but the temperature has drifted more than five degrees centigrade since the last Fine Tuning Calibration The YIG heater loop must be reset and new fine tuning data gathered Use Special Function 36 3 to reset the heater loop and gather the new fine tune data Usually the solution to error twenty eight E28 is to perform a Fine Tuning Calibra tion using Special Function 36 3 Error code E29 is generated if a Noise Figure Test Set coarse tuning calibration is required before making a single sideband measurement within the frequency range of 2401 to 18000 MHz Special Function 64 0 refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction must be performed The Noise Source HP 346B or HP 346C must have an ENR Excess Noise Ratio of at least 12 dB from 2401 to 18000 MHz
328. n made Operating errors can usually be cleared by using the front panel controls changing the equipment setup or correcting the HP IB code Entry errors require that a new keyboard entry or function selection be made A number of errors in this group may represent instrument malfunctions The operator should try to clear the error condition using the corrective actions shown in the table below before referring the unit for service Error 60 through Error 80 These are service errors which provide service related information Service errors are discussed in Section VIII of the Service Manual Error 100 through Error 105 These are Noise Figure Test Set operational and service errors Errors may also be classified as volatile or nonvolatile Nonvolatile errors typically occur when the instrument has received conflicting commands from the operator The instrument stops making measurements and waits for the conflict to be resolved by the operator An example of this type of conflict is selecting a corrected measurement when a calibration has not been performed All hardware errors are also nonvolatile Volatile errors typically represent invalid entries of either frequency special function codes numerical data or HP IB characters Volatile errors are cleared when a front panel key is pressed or when a serial poll is performed over the HP IB Upon clearing a volatile error the invalid entry is ignored by the instrument and measurements resume
329. n the right displays just after power on Error code E80 indicates a continuous memory failure The instrument may not retain data when powered down However the ability of the instrument to make valid measurements may not be impaired If E80 occurs press PRESET and proceed The occurrence of E80 implies that stored information such as the IF attenuator calibration was not retained Therefore error code E26 will appear Perform an IF attenuator calibration refer to the Calibration IF Attenuators Detailed Operating Instruction If E80 persists service should be performed on the internal battery and related circuits Refer to Service Related Errors in Section VIII Service _ Error code E102 indicates that auto sweep has been aborted in Measurement Modes 1 5 through 1 9 After one hundred sweeps auto sweep is aborted to protect the switches in the Noise Figure Test Set To disable auto sweep abort and error code E102 use Special Function 97 3 PRESET will re enable auto sweep abort and error code E102 The following program describes how an error can be displayed in English over HP IB NOTES This program was written in BASIC language 3 0 using the HP 9000 Series 200 Model 236 computer This program assumes that the Noise Figure Meter has an HP IB address of 8 and the interface card has a select code of 7 Also it is assumed that an error has occurred 100 OUTPUT 708 H1 ER OUTPUT FREQUENCY INSERTION GAIN IAND NOISE FIG
330. nction 70 1 through 70 8 and the ones 1 and zeros 0 that are displayed using Special Function 71 0 Attenuation Special dB Function 20 dB 10 dB ETE a Hee O OOOO tit CD O im et OO H Oe OM Om If any of the 60 or 70 series of Special Functions except 60 0 and 70 0 are active the calibration sequence does not override them Therefore to calibrate on one range only use any of these Special Functions except 60 0 or 70 0 Itis also true thatif any of these Special Functions are inadvertently active the calibration sequence will not cover the expected gain range Calibrate Manual Measurements RF Attenuation Selection Special Functions Section VIH Service is in the Service Manual The part number of the Service Manual is on the title page of this manual HP 8970B Description Procedure Operation Loss Compensation Special Function 34 Special Function 34 corrects for loss between the noise source and the device under test DUT and the DUT and the Noise Figure Meter The loss in dB and the temperature of the loss must be entered prior to enabling loss compensation Special Function 34 1 or else the default values of 0 dB and OK are used The temperature of the loss is the ambient temperature Therefore both the loss before the DUT and the loss after the DUT are assumed to be at the same temperature Only one temperature can be entered for both losses The temperature of the loss can be ente
331. nctions 2 and 17 Description Function 17 2 selects either lower or upper single sideband operation Special Function cont d 17 2 is used to enter a value from 2400 to 30000 MHz Once the value is entered a Noise Figure Test Set input frequency at or below the entered value will be a lower sideband measurement and a Noise Figure Test Set input frequency above the entered value will be an upper sideband measurement The procedure is to press 17 2 SPECIAL FUNCTION key in the data 2400 to 30000 MHz and press ENTER Once Special Function 17 2 is set up Special Function 17 0 may be keyed in if desired After PRESET 2401 to 16000 MHz is lower sideband and 16000 to 18000 MHz is upper sideband Procedure To select Special Function 2 or Special Function 17 key in the corresponding Special 3 228 Function code and then press the SPECIAL FUNCTION key In the case of Special Function 17 2 the SPECIAL FUNCTION key is pressed then data is keyed in and the ENTER key is pressed ee 2 om 5 E D D eo gej s 58 SSS o5 5S Special Function Program eax i cf i a 5 5 2s Code S ssl 28 sE f SE 7 23 88 38 Be es E w gs m escription CZ 33 28 82 22 8 23 Double Sideband no frequency offset Lower Single Sideband measurement frequency less than LO frequency BO or 2 0SP B1 or 2 1 SP Upper Single Sideband B2 or 2 2SP measur
332. nctions 70 71 and 72 Description IF attenuation selection display and hold are available in all measurement modes It should be noted however that only the hold capability Special Function 72 0 is normally used by most operators The hold is required during manual measurements refer to the Manual Measurements Detailed Operating Instruction for additional information The selection and display of specific IF attenuation settings are more likely to be used during adjustment procedures performance tests or troubleshooting procedures in some specialized applications these capabilities can be helpful but care must be exercised when using them It is possible to introduce some very subtle errors in the measurements that the Noise Figure Meter may not be able to guard against Additional information on how to use and interpret these Special Functions is contained in Section VIII Service Procedure To select a specific IF attenuation setting display or hold key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Program Code Special Function Lights Special Function Key tinuous Memory Can be Stored Special Function 0 0 Cenditions Presei and HP IB Ciear Conditions Special Function 0 9 Conditions and Hecalled Stored in Con 10 or 70 0SP Il or 70 1SP 12 or 70 2SP I3 or 70 8SP 14 or 70 4SP I5 or 70 5SP I6 or 70 6SP I7 or 70 7SP 18 or
333. nd conversion is done using the Noise Figure Test Set and the system local oscillator Special Function 17 selects a single sideband SSB or a double sideband DBS measurement for the second conversion or the first conversion in the case of Measurement Mode 1 5 The sideband selection for the first conversion Special Function 2 does not have to be the same as the sideband selection for the second _conversion And the sideband selection for the second conversion does not have to be the same as the sideband selection for the first conversion For measurement signals from 10 to 2400 MHz single sideband operation is all that is available For measurement signals greater than 2400 MHz single and double sideband operation are available Normally there is no need to change Special Function 17 Special Function 17 0 single sideband is the default Special Function 17 0 has been chosen for best system performance The following descriptions will help to clarify Special Function 17 a Special Function 17 0 selects single sideband operation for the Noise Figure Measurement System when the Noise Figure Test Set input frequency is greater than 2400 MHz Step c describes how to set the single sideband operation to either lower or upper sideband The measurement frequency is offset from the system local oscillator frequency plus or minus the IF depending upon how Special Function 17 2 has been set up The IF into the Noise Figure Meter t
334. nd listen the instrument sends Data mes sages when addressed to talk The instrument then remains configured to talk until it is unad dressed to talk by the controller To unaddress the Noise Figure Meter the controller must send either an Abort message a new talk address or a uni versal untalk command Talk Only Mode If the Noise Figure Meter s Talk address is valid and Special Function 4 2 is se lected the Noise Figure Meter is placed in the Talk Only mode In this mode the instrument is config ured to send Data messages whenever the busis in the data mode Each time the measurement is completed the measurement result will be output to the bus unless the listening device is not ready for data If the listener is not ready for data another measurement cycle is executed Data Output Format As shown below the output data is always formatted as a real constant first the sign then five digits leading zeros not sup pressed followed by the letter E and a signed power of ten multiplier The string is terminated by a carriage return CR and a line feed LF string positions 11 and 12 Data is always output in fundamental units that is Hz dB etc and the decimal point not sent is assumed to be to the right of the fifth digit of the mantissa Data values never exceed 1 x 10 The one exception to this format is the voltmeter mode as shown in Table 3 5 HP IB Data Output Summary The general data output format is as fo
335. near terms needed to produce NF pin Ficamp sys is the noise figure of the measurement system before the preamplifier is added Fampeys is the noise figure of the preamplifier and the measurement system Fampsys is the linear ratio of NF min Fin is the noise figure of the preamplifier Finp must be less than Fanpsys The equation will determine the gain of the preamplifier in linear terms needed to produce NF min To convert the linear gain of the preamplifier to a gain in dB use the following equation 10logi0 preamplifier linear gain gain in dB 3 203 Operation HP 8970B Preamplifier Selection contd Example In the following example the measurement system noise figure that will minimize measurement uncertainty will be determined and the gain of the preamplifier will be calculated NOTE It is assumed that NF au is 15 dB and Gaur is 10 dB Using the equation a measurement system noise figure is arrived at NF ain NF iu Gaut 15db NF min 15 dB 10 dB 15dB NF min 10 dB Using the second equation the gain of the preamplifier in linear terms is arrived at NF uin must be converted to linear terms NF nin is then substituted in the equation below as Famp sys Fampays 18 then 10 The value used for Fao ampeys is a typical measurement system value of 20 dB 100 linear If we use a preamplifier with a noise figure of 6 dB 4 linear the minimum gain of the preamplifier can be calculated using
336. ned in the Special Functions Detailed Operating Instruction HP 8970B Operation System Interface Bus Control conta Special Functions 45 through 49 Procedure cont d Special Function Program Code tein Enable System Local 46 0 LE Oscillator on the System Interface Bus Disable System Local 46 1 LD N Y N NC NC Off Oscillator on the System Interface Bus PlotterisontheSystem 47 0 PI N Y N NC Inerface Bus Enable plot data to be 47 1 on the Hewlett Packard Interface Bus Enable Noise Figure 48 0 i tinuous Memory Special Function 0 0 Conditions Preset and HP iB Clear Conditions Special Function 0 9 Conditions srm J a a iJ P z3 Can be Stored and Recalled Function Key Stored in Con NC On PM N Y N ini off wh z be 4 Meter to be the system controller on the System Interface Bus Disable Noise Figure 48 1 Meter as the system controller on the System Interface Bus Disable error 48 E48 48 2 Disable auto pass 49 0 control Enable auto passcontrol 49 1 EP Noise Figure Meter 49 2 CR releases active control of the System Interface Bus Noise Figure Meter 49 3 CT N N N takes active control of the System Interface Bus Noise Figure Meter 49 4 SB N N N performs a serial poll on the System Interface Bus Perform a seletive de 49 5 DD N N N Off Off vice clear of the pass through device on the Sy
337. ned in the Special Functions Detailed Operating Instruction tinuous Memory Spectal Function 0 0 Conditions Preset and HP IB Clear Conditions Speclal Function 0 9 Conditions Lights Special Function Key Stored in Con Can be Stored and Recalled 18000 18000 HP 8970B Operation Noise Figure Test Set YIG Filter Calibration conta Special Functions 36 and 64 Example To select a coarse tuning calibration LOCAL TEI Code oe eran Function am er GIGI Jin z gt program codes The following examples will describe how to perform a Coarse Tuning Calibration Fine Tuning Calibration and how to view a Coarse or Fine Tuning Calibration on an oscilloscope Coarse Tuning Calibration The following discussion will describe how to perform a Coarse Tuning Calibration NOTE A Coarse Tuning Calibration should only be done when the Noise Figure Measurement System is first configured and a freerunning source is being used as the system local oscillator or repairs have been made to the Noise Figure Test Set The Excess Noise Ratio ENR of the noise source should be 12 to 13 dB or more from 2401 to 18000 MHz or a preamplifier may be required a Connect the equipment as shown below SYSTEM LOCAL OSCILLATOR HP 83708 NOISE FIGURE METER D D cgpa 0 gon oo BBE nS Soon o oc DOPO wm NO SE SOURCE DRIVE OUTPUT NOISE SOURCE b
338. ng Calibration before Noise Figure Measurement System Cal Error E28 enabled Disable Fine Tuning Calibration before Noise Figure Measurement System Calibration is done Disable Fine Tuning Calibration before Noise Figure Measurement System Calibration is done Also error twenty eight is disabled Perform a Fine Tuning Calibration from START FREQ to STOP FREQ and enable Special Function 36 1 Enable a Fine Tuning Calibration at the current frequency Loss Compensation Sequence 2Enables Special Function Key LED to light when SEQ is pressed Noise Figure Test Set YIG Filter Calibration Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code N No Y Yes NC No Change Not Applicable IF Attenuators Calibration Special Function 33 1 HP IB Code Cl IF Special Function 33 1 is used the gain accuracy specification will be degraded from 0 15 dB to a typical value of 0 25 dB For more information refer to the Calibration IF Attenuators Detailed Operating Instruction 3 244 HP 8970B Operation Table 3 14 Special Function Summary 7 of 15 nd T Fep s a s w Ss 5E EB ES 5E 25 a ifs 2 t 5 Special Function Program Ze sart 5S s Sic Ze2s5 g aS References and Code Description f2 E2 38 SS 88 a gt mdi Cis ita cise a C AS Interpolated 39 0 DG Measurements Disables interpolate
339. nge this address if necessary The default address for the Noise Figure Test Set is 10 after using Special Function 0 9 e Special Function 46 0 must be active Enable system local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 f The address of the system local oscillator must match the address of the system local oscillator stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator System Interface Bus address to display and change this address if necessary The default address is 19 after using Special Function 0 9 g The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below 3 155 bat RS SA EE Requirements Procedure 3 156 Oneratian fir ov iva Measurement Mode 1 5 conra Special Function 1 5 HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 e HP 8673B C Standard Synthesized Signal Generator Special Function 41 3 e HP 8340B 8341B Sweep Oscillator Special Function 41 4 Custom local oscillator Special Function 41 5 The custom local oscillator program will support loca oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence
340. nt frequency increment These keys provide a convenient method of controlling the fixed frequency of the instrument for applications such as locating the minimum noise figure of an amplifier The allowable range of values for a frequency increment is e 1 to 1600 MHz for Measurement Modes 1 0 and 1 4 1 to 18000 MHz for Measurement Modes 1 5 and 1 9 e 1 to 99999 MHz for Measurement Modes 1 1 through 1 3 and 1 6 through 1 8 Fractional increments are rounded to the nearest 1 MHz Ifan attemptis made to enter an illegal frequency increment error code E35 is displayed and the entry is not made The Measurement Mode selected determines the fixed frequency increment default The table below lists the defaults for each of the Measurement Modes Measurement Fixed Frequency Mode increment 1 0 and 1 4 20 MHz 1 1 1 2 and 1 3 200 MHz 1 5 and 1 9 250 MHz 1 6 1 7 and 1 8 500 MHz As shown in the table the Measurement Modes have been placed into four groups If the fixed frequency increment is changed for one Measurement Mode the fixed frequency increment is changed for all the measurement modes of the group When going from one measurement mode to another the fixed frequency increment of the previous measurement mode is automatically saved by the Noise Figure Meter To change the size of the frequency increment press the FREQ INCR key enter a value for frequency in MHz and then press the ENTER key Use lt or to step the fr
341. nunciator lights when the Noise Figure Meter is addressed to talk or isin Talk Only mode The LISTEN annunciator lights when the Noise Figure Meter is addressed to listen The SRQ annunciator lights when the Noise Figure Meter is sending a Require Service message to the controller 3 Left Display Depending upon the selected functions the following information is displayed Frequency parameters always displayed in MHz i MHz resolution 10 to 1600 MHz measurement range in Mode 1 0 10 to 18000 MHz measurement range in Mode 1 5 up to 99999 MHz in Modes 1 1 through 1 4 and 1 6 through 1 9 Special Function codes are displayed as they are entered HP 8970B Spot ENR displayed in dB Temperature of the noise source displayed in C oF or K Sequence order Smoothing factor All data as it is being entered except ENR in the ENR versus Frequency tables EXT MIX external mixer annunciator lights when Measurement Mode 1 1 through 1 4 or 1 6 through 1 9 is active INSERTION GAIN Display Displays in dB the gain of the device under test DUT to two decimal places This display also shows ENR in dB when entering the ENR tables NOISE FIGURE Display Displays measured noise Five annunciators F dB Y dB F Te K and Y indi cate the noise figure display units This display is also used for power measurements displayed in dB error codes and during ENR Table entry displays the ENR ta
342. nunciator lights STORE RECALL and SEQ Check 33 34 35 36 37 38 Press PRESET Verify the left display shows 30 MHz NOTE During the STORE and RECALL checks the complete instrument configuration is stored and recalled The frequency change is merely a convenient indication that different setups have been stored and recalled Press STORE 1 Press Verify the left display shows 50 MHz Press STORE 2 Press RECALL 1 Verify the left display shows 30 MHz Press RECALL 2 Verify the left display shows 50 MHz Press and hold SEQ Verify the left display shows 1 Release SEQ Verify the left display shows 30 MHz Press and hold SEQ Verify the left display shows 2 Release SEQ Verify the left display shows 50 MHz Minus Check 39 Press Verify the left display shows System LO Check Optional for Measurement Modes 1 1 through 1 4 40 41 NOTE The following steps check the Noise Figure Meter s capability to control the System LO It is not necessary to perform this check unless the Noise Figure Meter is used for this purpose and a suitable System LO is available It is assumed in the following check that the SIB addresses used by the Noise Figure Meter and the System LO are compatible Connect the System LO to the Noise Figure Meter s SYSTEM INTERFACE BUS connector see Figure 3 9 Press 48 0 SPECIAL FUNCTION This will enable the Noise Figure Meter to be the system controller on the
343. nvalid HP IB code This enables a Require Service message to be sent Make controller wait two seconds to allow time for the Noise Figure Meter to send the Require Service message This step is not necessary if sufficient time is allowed Read the binary status of the controller s STATUS 7 2 V HP IB interface and store the data in vari able V in this step 7 is the interface s select code 10V 0 20 STATUS 7 7 V Display the value of the SRQ bit in this step 6 HP 85B and 10 HP 9836 are the SRQ bits for the controller numbered from 0 DISP SRQ BIT V 6 30 DISP SRQ BIT V 10 40 END Check that the SRQ value is 1 indicating the Noise Figure Meter issued the Require Service message HP 8970B Operation cz OPERATOR S CHECKS HP IB Functional Checks cont d Trigger Message Note This check determines if the Noise Figure Meter responds to the Trigger message This check assumes that the Noise Figure Meter is able to handshake recognize its own address make the remote local changes and send and receive Data messages Before beginning this check enter LOCAL 708 and press the Noise Figure Meter s PRESET key Then press 4 0 SPECIAL FUNCTION If an HP 9000 Series 200 300 controller is used a short program is required to perform this check HP 85B HP 9000 Series 206 300 eecripien BASIC BASIC Send the first part of the Remote message
344. ny IF requires recalibration refer Modes 1 1 1 3 1 6 and 1 8 to Special Functions 3 and 19 NV Not calibrated for the cur Perform calibration Changing rent LO frequency Meas the LO frequency requires urement Mode 1 2 and 1 7 recalibration refer to Special Function 3 NV Internal IF attenuators not Refer to the Calibration IF calibrated Attenuators Detailed Operating Instruction Overflow while calibrating Too much loss in calibration sys tem Check input gain calibration setting Special Function 32 Check for proper Noise Source 1 Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual HP 8970B Operation Error Messages and Recovery conta Error oa aie nl Recommended Action Comments cont Not Properly Calibrated For Corrected Measurement cont d operation Verify that the Noise Source can supply enough ENR Excess Noise Ratio Refer to comments 28 NV Noise Figure Test Set fine Refer to the Comments section at tuning calibration is needed the end of this instruction and the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction 29 NV Noise Figure Test Set coarse Refer to the Comments section at tuning calibration is needed the end of this instruction and the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction invalid Frequency Error Gene
345. o Gee rele as LASENLT290ENL1 a gt cole pears Code program codes Data Function Function Data Code For HP IB codes refer to Procedure above If Special Function 34 0 or 34 1 is selected the left display returns to the previously selected display The INSERTION GAIN and NOISE FIGURE displays are not affected by this function When a loss compensation entry is made in dB the temperature of the loss should also be entered The Noise Figure Meter assumes that the loss was not present during calibration If a2 dB attenuator is being used in the measurement 2 dB would be entered as the loss There is no need to characterize the device Special Functions Temperature Units Selection HP 8970B HP 8970B Operation Manual Measurement Functions Special Functions 14 and 15 Description The manual measurement functions calibrate and measure noise figure using a thermal hot cold noise source They also can be used to display either the current measurement or the result of the manual measurement Manual measurement functions are used for fixed frequency measurements only Three general requirements must be understood when performing manual measure ments 1 A stable reading must be stored in the Noise Figure Meter s memory prior to disconnecting the noise source This stable reading can be obtained by either activating the next manual measurement special function or by using the Trigger Selection Spec
346. o measure its own noise figure with HP 346B C Double Sideband BSB Noise Figure lt 18 dB typical SWR dB 2 5 1 typical Measurement Speed 6 to 9 measurements per second with minimum smoothing Sweep Speed at Minimum Smoothing for each Noise Figure Test Set band SSB1 10 to 1600 MHz 140 ms per frequency point SSB2 1 6 to 2 4 GHz 150 ms per frequency point SSB3 2 4 to 18 GHz 435 ms per frequency point DSB 2 4 to 18 GHz 150 ms per frequency point Functional Properties System Local Oscillator Control The Noise Figure Meter will control the system local oscillator used in the Noise Figure Measurement System The Noise Figure Meter will not control a local oscillator that is external to the Noise Figure Measurement System Displayed Measurement Frequency Range 10 to 99999 MHz 1 9 General Information HP 8970B Table 1 5 Recommended Test Equipment 1 of 2 i Instrument Specifications Recommended Model Use Attenuator 1 dB Steps 1 dB from 0 to 11 dB HP 8494A P A Steps Frequency Range 10 to 1600 MHz Option 001 Attenuator 10 dB Steps 10 dB from 0 to 70 dB HP 8495A P Steps Frequency Range 10 to 1600 MHz Option 001 Attenuator Fixed Attenuation 6 dB HP 8491A P A 6 dB Frequency Range 10 to 1600 MHz Option 006 Attenuation 10 dB HP 8491A Frequency Range 10 to 1600 MHz Option 010 Attenuation 20 dB HP 8491A l P Frequency Range 10 to 1600 MHz Option 020 Calculator Functions Div
347. om the power meter readings above them to yield the net error The error should be within 0 15 dB 4 18 HP 8970B Performance Tests PERFORMANCE TESTS 4 9 INSTRUMENT NOISE FIGURE PERFORMANCE TEST Specification INSTRUMENT NOISE FIGURE lt 7 dB 0 003 dB per MHz on the most sensitive input range Description A noise source is connected to the Noise Figure Meter INPUT and the instrument measures its own noise figure in the UNCORRECTED mode Equipment Noise Source ici vexies svat ae cxoesaawakes HP 346B Opt 001 Procedure 1 Connect the noise source between the SOURCE output and the INPUT of the Noise Figure Meter Turn on the Noise Figure Meter then press PRESET Set FREQ INCR to 100 MHz 2 Pressthe ENR key to access the working ENR table within the Noise Figure Meter Using the DATA keys and the ENTER key modify the 10 100 1000 and 2000 MHz ENR entries to correspond to the noise source ENR chart Exit the ENR table entry mode by pressing the FREQUENCY key 3 Use the INCREASE key to set the smoothing factor to 4 Select UNCORRECTED NOISE FIGURE 4 Note the NOISE FIGURE display reading at each frequency while using the step up key up arrow to tune the Noise Figure Meter through its tuning range The Noise Figure measurement results should be less than those shown in the table below Noise Figure dB Noise Figure dB Frequency Frequency Performance Tests HP 8970B PERFORMANCE TESTS 4 10 SPUR
348. on The user controlled local oscillator and an external mixer provide the first stage of conversion The user controlled local oscillator is not controlled by the Noise Figure Meter the user controlled local oscillator must be controlled by the user The second stage of conversion ts provided by the system local oscillator and the Noise Figure Test Set The Noise Figure Meter does control the system local oscillator and the Noise Figure Test Set Measurement Mode 1 7 provides the means of increasing the frequency range of the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator from 18000 to 99999 MHz Also this mode provides the means of using a fixed frequency user controlled local oscillator with a variable IF in order to measure over a band of frequencies less than 18000 MHz wide Frequency conversion is allowed for at the input to the Noise Figure Measurement System but notin the device under test DUT Single sideband operation and external filtering of the unwanted sideband are required A typical DUT is an amplifier with a bandwidth of less than 18000 MHz Although the signal measured at the Noise Figure Measurement System INPUT is always in the range of 10 to 18000 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For examp
349. on 44 8 must also be used to enable bit 7 in the status byte to generate an SRQ Complete HP IB capability as defined in IEEE Std 488 1978 and ANSI Std MC1 1 is SH1 AH1 T5 TEO L4 LEO SR1 RL1 PPO DC1 DT1 Co E1 3 46 HP 8970B Operation 2D Table 3 8 Noise Figure Meter HP IB Code to Parameter Summary 1 of 4 HP IB Code ie HP IB Code a gt HP 18 S Parameter AC System LO Auxiliary Commands Input Gain Calibration AD Sets the RAM address for modification CO 20 10 and 0 dB inspection or ROM address for inspection Cl 10 0 and 10 dB and disables auto increment mode C2 0 10 and 20 dB AF Enable Smoothing Factor C3 10 20 and 30 dB AI Sets the RAM address for modification DA Disable auto sweep abort inspection or ROM address for inspection DB dB and enables auto increment mode DC Disable Error 48 E48 DD Perform a Selective Device Clear of the Output to Oscilloscope Pass Through Device on the System AO Noise Figure and Gain Interface Bus Al Test Pattern DE DECREASE Smoothing A2 Noise Figure Only DF Measurement frequency is shown in the A3 Gain Only left display A4 Plot Noise Figure for X Y Recorder DG Interpolated measurements disabled A5 Plot Gain for X Y Recorder above 1600 MHz in Modes 1 5 through 1 9 A6 X Axis is Noise Figure and Y Axis is Gain DI Input to Noise Figure Meter Modes 1 0 Strip Chart Mode through 1 4 or Input to Noise Figure Test AT Enable recorder test Set Modes 1
350. on procedures Special Function Program Code Description code a gt Lights Spectal Function Key tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP 18 Clear Conditions Special Function 0 9 Conditions Stored In Con SOURCE Off N5 or 9 1SP uncalibrated SOURCE On N6 or 9 2SP uncalibrated SOURCE Off N7 or 9 3SP calibrated SOURCE On N8 or 9 4SP calibrated 1Tabie categories are explained in the Special Functions Detailed Operating Instruction To select an uncalibrated power measurement with the noise source on LOCAL omen Code amme Function keystrokes COIR g Ci program codes HP 39708 mr ovive Program Codes z gt indications Comments Related Sections EIN ONAA Uperation Power Measurements contd Special Function 9 For HP IB codes refer to Procedure above The NOISE FIGURE display shows the selected power measurement result in dB Special Functions 9 3 and 9 4 measure the power density delivered from the DUT The rest of the measurement system setup is corrected for by the calibration second stage correction The units shown in the NOISE FIGURE display are dB referenced to 290K 174 dBm Hz The equation is unknown power density dB 290 Power displayed 10 log Special Functions 9 1 and 9 2 are similar to 9 3 and 9 4 execpt that they are not ca
351. onente t at are in NOISE FIGURE MEASUREMENT UNCERTAINTY d8 t 0 90 5 0 10 0 15 0 20 0 25 0 30 0 MEASUREMENT SYSTEM NOISE FIGURE d8 Noise Figure Measurement Uncertainty versus Measurement System Noise Figure This is a graph of overall noise figure measurement uncertainty versus measurement system noise fig ure DUT F G is the device under test noise figure plus gain in dB The curves are based on typical values of noise figure instrumentation uncertainty 0 1 dB gain instrumentation uncertainty 0 15 dB noise source ENR uncertainty 0 1 dB measure ment system SWE 1 7 noise source SWR 1 15 DUT input SWR 1 5 and DUT output SWR 1 9 Determining the measurement system noise figure that minimizes measurement uncertainty Selecting the preamplifier Determining Measurement System Noise Figure The first step is to determine the measurement system noise figure that minimizes measurement uncertainty First add the DUT noise figure and gain dB values If that number is greater than 17 dB use the following equation to determine the measurement system noise figure that minimizes measurement uncertainty NFE min N F aurt Gaum 15 dB NOTE If the noise figure and gain of the DUT is less than 17 dB you will only be able to reduce the measurement system noise figure effect on uncer tainty not minimize it By reducing measurement system noise figure to 2or3dB using a preamplifier you will sign
352. ont panel keys except PRESET CALIBRATE and LOCAL are disabled To start a calibration the CALIBRATE key must be pressed twice Pressing CALIBRATE before calibration is complete terminates the calibration B CORRECTED NOISE FIGURE AND GAIN Key Configures the Noise Figure Meter to measure noise figure and gain with second stage correction that is only the noise figure and gain of the device under test is displayed A calibration must be completed prior to making corrected noise figure and gain measurements INPUT This female type N INPUT connector is used to connect the device under test to the Noise Figure Meter in Modes 1 0 through 1 4 in Modes 1 5 through 1 9 the Noise Figure Test Set is connected to this input The nominal input impedance is 50 ohms Speci fied operating input level is less than 10 dBm The frequency range at the INPUT connector is 10 to 1600 Figure 3 7 MEASUREMENT and INPUT Features nen 1 Tha MR MHz The maximum average input power for a CW signal is 20 dBm The maximum peak input power for a pulsed signal is 20 dBm Damage to the instrument can be caused by connecting signals to INPUT that exceed 20 dBm or 20 Vde SMOOTHING Keys INCREASE and DECREASE the number of measurements averaged smoothing factor when displaying measurement results When pressed these keys cause the smoothing factor to appear in the left display The smoothing factor ranges from 1 to 512 and changes in fact
353. ontrolled by the Noise Figure Meter b Use the system LO s manual to look up the HP IB program codes for the above functions c Use Table 3 11 located in Remote Operation near the front of this section to look up the decimal equivalent for each of the ASCII characters used for the program codes d On the Noise Figure Meter press 42 0 SPECIAL FUNCTION to display the current number stored in the first of the fifteen data locations Enter the decima equivalent of the desired ASCII character from the front panel of the Noise Figure Meter The allowable range of decimal values is 0 to 255 e Press the ENTER key on the Noise Figure Meter s front panel The next data location available for modification will appear in the Noise Figure Meter s left display If no change to the existing data is desired press ENTER to advance to the next data location AP 89 06 Procedure cont d Operation Programming The System LO conta Special Function 42 f Continue stepping through the data locations until all fifteen have been filled If all of the auxiliary command data locations are not used in a specific application always enter zeros in the remaining locations to avoid possible HP IB command errors After all fifteen locations are displayed the Noise Figure Meter returns to the previous front panel setup the next time ENTER is pressed It is also possible to exit Special Function 42 0 at any time by pressing FREQUENCY and still r
354. ontroller NOTE The Noise Figure Meter is set up to be the system controller when shipped from the factory after memory RAM loss or when Special Function 0 9 is used f Connect the Noise Figure Meter external computer and the second instrument controller to the Hewlett Packard Interface Bus HP IB g Connect the Noise Figure Meter second instrument controller the local oscillator plotter and any other instruments to be controlled to the System Interface Bus SIB Computer Control The following discussion will describe how the computer will pass control between the Noise Figure Meter and the other controller If the Noise Figure Meter has control of the System Interface Bus and the other controller needs to have control the computer will send 49 2SP or the HP IB code CR This will convey to the Noise Figure Meter to release control of the System Interface Bus The other controller will be told to take control using the appropriate code for that instrument The other controller will now have control of the System Interface Bus and the Noise Figure Meter will display the message Ctrl OFF When the Noise Figure Meter needs to be controller the computer must tell the other controller to release control using the appropriate code for that instrument The Noise Figure Meter is then told to take control using 49 3SP or the HP IB code CT Once the Noise Figure Meter is the controller it will no longer display the message
355. or 1 FO or AFLEN Smoothing Factor 2 Fi or AFZ2EN Smoothing Factor 4 F2 or AF4EN Smoothing Factor 8 F3 or AF8EN Smoothing Factor 16 F4 or AFI6EN Smoothing Factor 32 F5 or AF382EN Smoothing Factor 64 F6 or AF64EN Smoothing Factor 128 F7 or AFI28EN Smoothing Factor 256 F8 or AF256EN Smoothing Factor 512 F9 or AF512EN For HP IB codes for Special Function 13 refer to Procedure above 3 231 Operation Indications Comments Related Sections 3 232 HP 8970B Smoothing Averaging cont d includes Special Function 13 The current smoothing factor is displayed in the left display whenever the INCREASE key or the DECREASE key is depressed The smoothing factor can be changed while swept measurements are in progress However the smoothing factor cannot be changed during calibration For fixed frequency measurements arithmetic smoothing is mainly useful in HP IB systems Exponential smoothing is best for reading measurement results on the front panel display or on an oscilloscope When using exponential smoothing any time the fixed frequency changes a number of measurements equal to the smoothing factor is made before any results are displayed During this time the NOISE FIGURE display shows four dashes In exponential smoothing to reduce the settling time after a large measurement change press the FREQUENCY key to reset the display to the current measurement value Calibrat
356. or additional features that would make them a better choice in some applications HP 8970B General Information Table 1 1 Noise Figure Meter Specifications 1 of 2 Characteristics Performance Limits NOISE FIGURE MEASUREMENT Range 0 to 30 dB 0 01 dB 0 1 dB Resolution For a noise source in a 0 to 55 C envi ronment with an ENR of 14 to 16 dB Instrumentation Uncertainty Jitter Peak to peak Y factor At minimum smoothing variation lt 0 15 dB Peak to peak Y factor With increased smoothing smoothing variation lt 0 02 dB factor set to 64 Note Jitter in noise figure is equiv alent to jitter in Y factor to within 10 for ENR gt 14 dB and F lt 4 dB At minimum smoothing jitter can limit accuracy the small jitter at high smoothing does not GAIN MEASUREMENT Range 20 to gt 40 dB For total noise figures lt 30 dB 0 01 dB 0 1 dB Gain gt 9 99 dB Gain lt 9 99 dB Resolution Instrumentation Uncertainty 0 15 dB INPUT Frequency Range Tunable from 10 to 1600 MHz Frequency Resolution 1 MHz 1 MHz 1 of frequency From 10 to 40 C 6 MHz maximum Tuning Accuracy Noise Figure lt 7 dB 0 003 dB MHz For input power levels below 60 dBm Input SWR Reflection Coefficient lt 1 7 0 26 500 reference impedance Maximum Operating
357. or properly To account for the filter s conversion loss enter the filter s loss in dB into the Noise Figure Meter using Special Function 34 2 loss between the noise source and device under test Also enter the room temperature of the filter using Special Function 34 3 To turn loss compensation on use Special Function 34 1 SYSTEM LOCAL OSCILLATOR OUTPUT NOISE SOURCE PREAMPLIFIER iF THE PREAMPLIFIER IS USED DURING THE MEASUREMENT iT MUST BE USED DURING CALIBRATION g Calibrate the Noise Figure Measurement System and fine tune the Noise Figure Test Set in Mode 1 9 by pressing CALIBRATE twice or sending HP IB code CA PRESET enabled a fine tuning calibration Special Function 36 0 each time the Noise Figure Measurement system is calibrated h To make the measurement set up the equipment as shown below SYSTEM LOCAL OSCILLATOR HP 89708 NOISE FIGURE METER NOISE SOURCE DRIVE OUTPUT eF ILTER NOISE SOURCE Ee LIF A SINGLE SIDEBAND MEASUREMENT IS BEING MADE A FILTER MUST BE USED 3 187 Operation Example cont d Program Codes Indications Comments 3 188 HP 8970B Measurement Mode 1 9 contd Special Function 1 9 NOTE For the Noise Figure Measurement System specifications to be valid the measurement must use the same START FREQ STOP FREQ and STEP SIZE that was used for calibration None of the calibrated points can be skipped Also the measurement must be
358. or the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or output power 3 135 We OUR CARTE BAL VW VRS Measurement Mode 1 1 cont d Special Function 1 1 Requirements Use Special Function 42 to define a new program for other system local oscillators cont d Procedure There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement uncer tainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selection Detailed Operating Instruction a Verify that the minimum requirements specified under Requirements are satisfied b Press 1 1 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 1 c Set frequency parameters including the fixed IF Special Function 3 0 d Calibrate in Mode 1 1 If a preamplifier will be used in the measurement the preamplifier must be used during the calibration e Insert DUT and measure Example To make a swept double sideband CORRECTED NOISE FIGURE AND GAIN meas urement in the 6 to 12 GHz range
359. ors of 2 Pressing INCREASE doubles the smoothing factor Pressing DECREASE halves the smoothing factor Both INSERTION GAIN and NOISE FIGURE displays are smoothed Increasing the smoothing reduces the jitter in the display 5 UNCORRECTED NOISE FIGURE Key Configures the Noise Figure Meter to measure noise figure without second stage correction that is the noise contribu tion of the measurement system is included in the reading in the NOISE FIGURE display 3 13 Operation NOISE SOURCE DRIVE OUTPUT drives a noise source on and off with 28V pulses and is in parallel to the front panel NOISE SOURCE DRIVE OUTPUT Only one noise source can be connected at a time INPUT is a rear panel input for coupling the output signal from the device under test or Noise Figure Test Sei into the instrument Damage to the instrument can be caused by connecting signals to INPUT that exceed 20 dBm or 20 Vdc IF provides a rear panel output for the Noise Figure Meter s last IF 20 MHz immediately prior to the detector The power level is 50 to 30 dBm nominal Output impedance is 500 nominal Q DET provides an output from the noise power detector Level is 0 1 to 1 0 Vde nominal floating NOTE DET is a direct connection to the instru ment s detector Loading or injecting a signal may cause inaccurate readings Only connect this output to instrumentation with floating inputs Output impedance is 10 kQ nominal GAIN
360. ovides a TTL high signal to lift the pen Output impedance is 1000 Figure 3 8 Rear Panel Features 3 14 HP 8970B Operation OPERATOR S CHECKS 3 10 OPERATOR S CHECKS 3 11 Basic Functional Checks Description Equipment Procedure The overall operation of the Noise Figure Meter is checked using a noise source and an analog display module If the Noise Figure Meter is to be used to control the System LO the optional System LO Check at the end of this procedure verifies that capability This check should be performed sequentially GURE METER ANSLO Spul FEATS DISPLAY MODULE SYSTEM LOCAL OSCILLATOR NOISE SOURCE E Figure 3 9 Basic Functional Checks Setup Noise Source 246 hiniwaw saatveuteees HP 346B Option 001 Analog Display Module HP 1332A Options 101 and 315 System HO sraao uen denese se eens HP 8671B Preliminary Check 1 Remove any cables from the Noise Figure Meter s INPUT and SOURCE Set the LINE switch to OFF and then back to ON Verify the front panel LED annuncia tors display segments decimal points and key lights turn on for approximately two seconds Then verify that Ctrl appears in the INSERTION GAIN display and on or OFF appears in the NOISE FIGURE display If the Noise Figure Meter is the system controller on the System Interface Bus Special Function 48 0 on will be displayed Ifthe Noise Figure Meter is not the system controller on the S
361. pecial Function Program Code Description Code HP iB Lights Special Function Key Stored in Con tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions NO or 10 0SP N1 or 10 1SP N2 or 10 2SP N3 or 10 38SP N4 or 10 4SP mG mG a eG eG iTable categories are explained in the Special Function Detailed Operation Instruction To have measured noise displayed as Y factor in dB LOCAL yamnasa C e am yama FUNCTION amm ee CICICIG oji i gt program codes For HP IB program codes refer to Procedure above The selected display unit appears on the right side of the NOISE FIGURE display Special Function 10 has no effect on the INSERTION GAIN display 32 dB is the maximum value that can be displayed in units of F dB Readings above this value cause the NOISE FIGURE display to show two dashes The smoothed number is the value that is checked against 32 dB Therefore if the display is flashing between approximately 30 dB and increasing the smoothing may provide a stable display if the noise figure is less than 32 dB The maximum value allowable for Te K is 9999K noise figure of 15 5 dB 3 85 Operation HP 8970B Display Units Selection contd Special Function 10 Comments The maximum value allowable for F is 9999 noise figure of approximately 40 dB cont d Equations for th
362. peration Sweep contd As shown in the table the Measurement Modes have been placed into four groups When the start stop and step size frequencies are changed for one measurement mode the start stop and step size frequencies are changed for all the measurement modes of the group When selecting a new Measurement Mode the Noise Figure Meter automatically saves the start stop and step size frequencies from the previous meas urement mode The minimum step size is 1 MHz The maximum number of frequency points allow able in one sweep is STOP FREQ START FREQ 1 STEP SIZE If the fractional part factional part of STOP FREQ START FREQ STEP SIZE does not equal 0 then add 1 However the maximum number of frequency points that should be used when the sweep is displayed on an oscilloscope is 251 If more points are swept multiple readings could occur at some points Other limitations may be caused by the system LO Two sweep modes are available Auto and Single Each mode uses the sweep para meters that were previously set Auto mode executes a repetitive sweep restarting at the end of each sweep Single mode executes one sweep only At the end of a single sweep the instrument remains tuned to the stop frequency Sweep Range Selection The START FREQ and STOP FREQ keys set the starting and stopping points of the frequency sweep STEP SIZE sets the frequency increment Sweep parameters are selected in a Function Da
363. plicable 3 246 HP 8970B Operation Table 3 14 Specia Function Summary 9 of 15 References and Description P Comments tinuous Memory Can be Stored and Recalled Special Functions 0 8 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Speciai Function Program Cade Name coe ea Service 44 8 Q8 Stored in Con Lights Special Function Key Enable Extended Status Byte Set Extended Status Byte Mask Ni NINO Off Off 44 9 RE Noise Figure Test Set Control Enable Noise Figure Test Set in Modes 1 5 through 1 9 Enable Noise Figure Test Set on the System Inter face Bus in all Modes TD Disable Noise Figure Test Set on the System Interface Bus YININC NC On System Interface Control YIN NC NC Off Off System Local Oscillator Control Enable LO on the System Interface Bus Disable LO on the System Interface Bus System Interface Bus Control Plotter Control on System Interface Bus Plotter is on the System Interface Bus Enable plot data to be read on HP IB Data Output to Oscilloscopes Recorders and Plotters and System Interface Bus Control Noise Figure Meter is the System Controller on the System Interface Bus Noise Figure Meter is not the System Controller on the System Interface Bus System
364. pment as shown below 3 157 Uperation Fr oyun Measurement Mode 1 5 contd Special Function 1 5 SYSTEM Example LOCAL OSCILLATOR cont d f SIB 2 NOISE SOURCE DRIVE OUTPUT wtf THE PREAMPLIFIER 1S NEEDED FOR THE MEASUREMENT iT MUST BE USED DURING CALIBRATION f Calibrate and fine tune in Measurement Mode 1 5 by pressing CALIBRATE twice or send HP IB code CA PRESET enabled a fine tune Special Function 36 0 to be done each time a calibration is done g To make the measurement set up the equipment as shown below SYSTEM LOCAL OSCILLATOR PREAMPLIFIER IF NEEDED gags Boon amp BEDD S NOISE SOURCE DUT DRIVE OUTPUT NOISE SOURCE NOTE For the Noise Figure Measurement System specifications to be valid the measurement must use the same START FREQ STOP FREQ and STEP SIZE that was used for calibration None of the calibrated points can be skipped Also the measurement must be done in the same direc tion as the calibration for example from start frequency to stop frequency h Press CORRECTED NOISE FIGURE AND GAIN or send HP IB code M2 i Press SINGLE or send HP IB code W2 The Noise Figure Measurement System will sweep from 3000 MHz to 4000 MHz in 10 MHz steps and halt 3 158 TIM OAGVAY HP 8970B Program Codes CZD indications Related Sections Operation Measurement Mode 1 5 cont d Special Function 1 5 The HP IB code for Measurement Mode 1 5 is E5 or 1 5SP
365. r controlled local oscillator must be set up for each of the calibration points If external filtering and a preamplifier are required for the measurement external filtering and the preamplifier must be used during calibration j Insert the DUT into the measurement system and make a noise figure or noise figure and gain measurement Example To make a swept single sideband CORRECTED NOISE FIGURE AND GAIN meas urement in the 20 to 24 GHz range in 200 MHz steps with a fixed IF of 3 5 GHz NOTE This example assumes that the Noise Figure Meter is acting as a controller and the minimum requirements specified under Requirements are satisfied Refer to Comments for a brief description of using an external controller when in Measurement Mode 1 6 a Press PRESET to establish initial conditions NOTE Single sideband Special Function 17 0 was enabled for the Noise Figure Test Set when PRESET was pressed Measurement Mode 1 6 must be activated prior to entering the frequency parameters to avoid error E35 entered value is out of range b Press 1 6 SPECIAL FUNCTION to activate Measurement Mode 1 6 c Set the frequency parameters for both the calibration and measurement 3 162 Qmnaratinn HP R970R HP 8970B Operation Measurement Mode 1 6 conta Special Function 1 6 Example d Enter actual ENR for the noise source if this has not previously been done cont d e Press 2 1 SPECIAL FUNCTION to select a lower sideband measure
366. r the ENR table number for calibration or the ENR table number for a measurement key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Next enter the appropriate value using the DATA keys and press ENTER HP 8970B Operation Spot ENR Thot Teora and ENR Table Selection conrad Procedure cont d Example Program Codes lt i gt Indications Special Functions 5 and 6 Special Function Program Code mein om aD tinuous Memory Special Function Preset fand HP IB Clear Conditions Special Function 0 9 Conditions 0 0 Conditions SS a Sx Ss 22 2s 7 a Stored In Con Can be Stored and Recalled Use ENR Table Data 5 0 50 or 5 0SP N Y Y On On On Use Spot ENR Data 5 1 Slor5 1SP Y Y Y off Off Off Display Current 5 2 SEor5 28SP N N N Off Off Off ENR in dB Enter and Use Spot 5 3 INEor5 3SP N Y Y NC j15 2dB115 2dB ENR Enter and Use Tho 5 4 iTHor54SP N Y Y NC 9893K 9893K Enter Noise Source 5 5 ISNor5 5SP N Y N NC NC NC Identifier Noise Source Catalog 5 6 NSor5 6SP N N N NC NC NC ENR Table for 5 7 ECor5 7SP N Y Y NC 0 0 Calibration ENR Table for 5 8 jiEMor5 8SP N Y Y NC 0 0 Measurement Enter Toa 6 0 TCor6 0SP N Y Y NC 1296 5K 296 5K Table categories are explained in the Special Functions Detailed Operating Instruction To enter and use a value of 9800K for Thot assuming Special Function 11 0 is active LOCAL gaama Code aroan
367. r Calibration Detailed Operating Instruction There are many possible measurement procedures However the following general procedure applies to all cases NOTE High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement un certainty For more information on determining if a preamplifier is needed and selection of the preamplifier refer to the Preamplifier Selec tion Detailed Operating Instruction BAA We the Procedure cont d Example HP 2Q7NR Wperauon Measurement Mode 1 9 conrad Special Function 1 9 a Verify that the minimum requirements specified under Requirements are satisfied b Press PRESET c Press 1 9 SPECIAL FUNCTION to set the Noise Figure Meter to Measurement Mode 1 9 d Set frequency parameters including the fixed frequency for the user controlled local oscillator Special Function 3 1 e Enter ENR tables for calibration and measurement use Special Functions 5 7 and 5 8 f Select sideband operation desired Special Function 2 and 17 g Set up the user controlled local oscillator to produce the desired output as specified by Special Function 3 1 h Perform a Noise Figure Test Set Fine Tuning Calibration For more information refer to the Noise Figure Test Set YIG Filter Calibration
368. r Hold waamaertna oo nase v n lor or or Table categories are explained in the Special Functions Detailed Operating Instruction Section VIII Service is in the Service Manual The part number of the Service Manual is on the title page of this manual HP 8970B Example Program Codes indications Comments Related Sections Operation RF Attenuation Selection conta Special Functions 60 61 and 62 To select the RF attenuator hold function LOCAL roves COGE ameno Function keystrokes 6 2 e Gi Gi program codes For HP IB codes refer to Procedure When Special Function 61 is implemented four digits appear in the left display The digits are either 1 yes or 0 no to indicate whether or not the corresponding 10dB pads and 20 dB amplifier are switched into the Input Assembly circuits see Service Sheet 1 in Section VIII Service The first third and fourth digits each represent 10 dB 10 dB Pad No 1 10 dB Pad No 2 and 10 dB Pad No 3 respectively The second digit represents 20 dB 20 dB Input Gain Amplifier To obtain the RF attenuator setting add the attenuation that is represented by each digit in the display For example a display of 1 1 1 0 indicates an RF attenuation setting of 0 dB The following table lists the RF attenuation available Special Functions 60 1 through 60 6 and the ones 1 and zeros 0 that are displayed using Spe
369. r and Use Thot 5 5 SN Enter Noise Source Identifier 5 6 NS Noise Source Catalog 5 7 EC ENR Table for Calibration 5 8 EM ENR Table for Measurement Teold Setting 6 0 TC Enter Teold Output to Oscilloscope 7 0 AO Noise Figure and Gain 71i Al Test Pattern 7 2 A2 Noise Figure Only 7 3 A3 Gain Only 7 4 A8 Oscilloscope Display Cursor Enabled 7 5 A9 Oscilloscope Display Cursor Disabled Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code 3 51 Operation iz HP 8970B Table 3 9 se Function to HP IB Code 2 of 7 Function Enter Oscilloscope Limits Power Measurements Noise Figure Display Units Select Noise Source Temperature Units for Data Input Display Resolution Smoothing Averaging Manual Measurement Functions Display Control Noise Figure Test Set Internal Sideband Frequency Offset Noise Figure Measurement System Internal IF 3 52 Most Special Functions can be programmed using either the code number followed by SP or the HP IB Code Description Noise Figure Lower Limit Noise Figure Upper Limit Gain Lower Limit Gain Upper Limit SOURCE Off uncal SOURCE On uncal SOURCE Off cal SOURCE On eal FdB F Y dB Y Te K K eE F Maximum Resolution Less Resolution on Noise Figure Less Resolution on Gain Exponential Smoothing Ar
370. r for the suffix and the suffix characters can be a maximum of twenty four 24 characters The prefix suffix and count characters are entered in a manner similar to the auxiliary commands that is the decimal equivalent of each ASCII character is entered into the Noise Figure Meter Since the count characters are decimal they are entered as they are Once the prefix and suffix have been entered Special Function 42 5 is used to enter the actual power level 0 to 30 dBm For an example of using the custom local oscillator program and Special Function 42 6 refer to Example two 2 at the end of this instruction With the other local oscillator programs Special Functions 41 0 through 41 4 Special Function 42 5 sets the power level and the prefix and suffix for the output signal power level Special Function 42 7 is used with the custom local oscillator program Special Function 41 5 ONLY Special Function 42 7 is used to properly format the command sequence that is used to set the output frequency Special Function 42 7 allows entry of the prefix and suffix for the output frequency The count character for the prefix the prefix characters the count character for the suffix and the suffix characters can be a maximum of twenty four 24 characters The prefix suffix and count characters are entered in a manner similar to the auxiliary commands thatis the decimal equivalent of each ASCII character is entered into the Noise Figure Meter Since
371. r test to eliminate the unwanted sideband f Configure the user controlled local oscillator to produce a 4 GHz IF at the input of _ the Noise Figure Measurement System The correct frequency to set the user controlled local oscillator to can be viewed by using Special Function 3 2 3 179 Operation HP 8970B Measurement Mode 1 8 conta Special Function 1 8 Example g To calibrate the Noise Figure Measurement System and perform a Noise Figure cont d Test Set Fine Tuning calibration set up the equipment as shown below SYSTEM LOCAL OSCILLATOR 29 g ggo pooen pees SS NOISE SOURCE DRIVE OUTPUT INPUT NOISE PREAMPLIFIER SOURCE v elf THE PREAMPLIFIER IS USED DURING THE MEASUREMENT iT MUST BE USED DURING CALIBRATION NOTES For a single sideband measurement the external filter is not included during calibration During calibration the Noise Figure Meter only accounts for loss after the device under test Since the filter is before the device under test the loss of the filter is not accounted for properly To account for the filter s conversion loss enter the filter s loss in dB into the Noise Figure Meter using Special Function 34 2 loss between the noise source and device under test Also enter the room temperature of the filter using Special Function 34 3 To turn loss compensation on use Special Function 34 1 h Calibrate and fine tune in Measurement Mode 1 8 by pressing
372. r twenty eight warning The user can perform a Fine Tuning Calibration using Special Function 36 3 This special function is useful if the user is not concerned with absolute accuracy and understands the accuracy problems associated with not having the Noise Figure Test Set fine tuned Possible causes of error twenty eight are found in the Comments section at the end of this instruction Even though the error is not displayed a warning indication still exists in the Noise Figure Meter s extended status byte Normally using Special Function 36 2 is not a good idea because it removes the safeguard of the Noise Figure Measurement System checking to see if a Fine Tune Calibration is needed Special Function 36 3 will perform a Fine Tuning Calibration of the Noise Figure Test Set immediately Special Function 36 1 is enabled since the Fine Tuning Calibration has been completed using Special Function 36 3 Additional Fine Tuning Calibrations are not needed unless the temperature inside the Noise Figure Test Set drifts five degrees centigrade or new frequency points are to be measured Special Function 36 4 allows the user to define additional Fine Tuning Calibration frequencies between the frequencies set by START FREQ STOP FREQ and STEP SIZE The passbands are aligned for the frequency point added by Special Function 36 4 but the point added is not a calibrated point of the Noise Figure Measurement System In other words any noise contributed by
373. ral Remedy Change frequency parameter and repeat measurement 30 V Start frequency is greater Set start frequency or lower limit than stop frequency during toa value less than the stop calibration or plot Or the frequency or upper limit lower limit is greater than the upper limit noise or gain during sweep 31 vV Number of calibration points Reduce the number of calibration exceeds 181 points Reduce calibration range or increase step size 32 V LO set by Special Function Change IF START FREQ STOP 3 1 frequency will be out of FREQ or sideband selection so range that system LO does not tune through 0 MHz 33 V IF into Noise Figure Meter If single sideband has been select will be out of range ed change START FREQ STOP FREQ or LO set by Special Func tion 3 1 frequency so that the dif ference between the LO set by Specia Function 3 1 frequency and the start or stop frequency is greater than 10 MHz and less than 1600 MHz modes 1 1 to 1 4 or 3 97 Operation HP 8970B Error Messages and Recovery conta Error on Hi obec eh Recommended Action Comments cont i Invalid Frequency Error cont d 18000 MHz 1 6 to 1 9 If sum function Special Function 2 3 is being used change START FREQ STOP FREQ or LO set by Special Function 3 1 frequency so that LO plusSTART or STOP FREQ is within 10 1600 MHz range 34 NV Double sideband is not Use single sideband Special allowed in Measu
374. ration section of the Gain Meas urement Uncertainty Performance Test in Section IV This method maintains the gain instrumentation uncertainty specification of 0 15 dB e Use Special Function 33 1 to perform the IF attenuator calibration If Special Function 33 1 ts used the gain instrumentation uncer tainty specification will be degraded from 0 15 dB to a typical value of 0 25 dB Because of this degradation Hewlett Packard recommends that one of the other methods be used to calibrate the IF attenuators 3 67 Operation Description Procedure a ore Program HP 8970B Calibration IF Attenuators conta Special Function 33 1 Special Function 33 1 is used to calibrate the IF Attenuators The HP 346 B C noise source MUST be connected to the Noise Figure Meter The Noise Figure Meter turns on the noise source and uses its own internal noise power detector to measure each IF attenuator This data is used to correct the gain readings during gain measurement After the IF attenuation calibration is completed this data is stored in the instru ment s continuous memory and is retained when power is removed Completion of IF calibration does not set the CALIBRATION COMPLETE bit of the HP IB status byte To calibrate the IF Attenuators connect the HP 346 B C noise source to the instru ment s INPUT connector enter 33 1 and then press SPECIAL FUNCTION gt Description tinuous Memory Special Function 0 0 Conditions P
375. ration performance testing adjust ment or service is found in appropriate places throughout the Operating and Service manuals 1 4 INSTRUMENTS COVERED BY MANUAL Attached to the rear panel of the instrument is a serial number plate The serial number is in the form 0000A00000 The first four digits and the letter are the serial number prefix The last five digits are the suffix The prefix is the same for identical instruments it changes only when a configuration change is made to the instru ment The suffix however is assigned sequen tially and is different for each instrument The contents of this manual apply directly to instru ments having serial number prefix es as listed under SERIAL NUMBERS on the title page 1 5 MANUAL CHANGES SUPPLEMENT An instrument manufactured after the printing of this manual may have a serial number pre fix that is not listed on the title page This un listed serial number prefix indicates that the instrument is different from those documented in this manual The manual for this newer instru ment is accompanied by a Manual Changes supplement The supplement contains change instructions that explain how to adapt the man ual to the newer instrument 1 1 General Information MANUAL CHANGES SUPPLEMENT cont d In addition to change information the supple ment may contain information for correcting errors in the manual To keep the manual as current and as accurate as possible Hewlet
376. re defined in IEEE Std 488 1978 Knowledge of these may not be necessary if your controller s manual describes programming in terms of the twelve HP IB Messages shown in the left column 3 35 Operation HP 8970B gt Table 3 3 Message Reference Table 2 of 2 HP IB Related Commands Interface Rl Require Yes The Noise Figure Meter sets the SRQ bus control S Service line true if an invalid program code is received unless disabled The following conditions also set SRQ true when they occur if they are enabled by the operator to do so Data Ready Noise Figure Meter Calibration Complete SRQ on the System Interface Bus Noise Figure Meter received control of the System Interface Bus Instrument Error has occurred and Extended Status Byte enabled condi tions are active e Status Byte Yes The Noise Figure Meter responds to a Serial Poll Enable SPE bus command by sending an 8 bit byte when addressed to talk If the instrument is holding the SRQ control line true issuing the Require Service message bit 6 RQS bit in the Status Byte and the bit representing the condition causing the Require Service message to be issued will both be true The bits in the Status Byte are latched but can be cleared by removing the causing condition and reading the Status Byte or by sending the program code OS output status or RS reset status Status Bit No The Noise Figure Meter does not respond to a parallel poll
377. red in Kelvins degrees Fahrenheit or degrees Celsius Temperature units are selected by Special Function 11 The allowable range of loss in Kelvins is 0 to 9999 The allowable range of loss in dB is 100 to 100 To display enter or enable loss compensation key in the corresponding Special Function code and then press the SPECIAL FUNCTION key z 5 FEJES fp u 2138 Special Function Program s amp 3 E 25 22 Code 22 E2 es eo BE S Turn loss com Y On On On pensation off Turn loss com Y Off Off Off pensation on Display and enter Y NC 0dB 0dB the amount of loss between the noise source and the DUT in dB Display and enter the temperature of losses units are determined by Spec ial Function 11 Display and enter the amount of loss between the DUT and the Noise Fig ure Meter in dB NC OK OK NC 0dB 0dB Table categories are explained in the Special Functions Detailed Operating Instruction 3 119 Example Program Codes indications Comments Related Sections 3 120 Operation Loss Compensation contd Special Function 34 To compensate for a loss of 3 dB between the noise source and the DUT at a temperature of 290K assume Special Function 11 0 is active temperature in K and to enable the loss compensation function Function gue Data oom Function SPECIAL FURCTION LOCAL keystrokes ej Cejfe l
378. red with REOEN b Each of the desired conditions of the Status Byte may be set individually Special Functions 44 1 through 44 6 or all the conditions may be set at once Special Function 44 7 c Toset conditions individually send the appli cable HP IB Codes from Table 3 7 To set all the desired conditions at once send the total binary weight of the bit positions desired The command sequence would be as follows RM132EN RM is the HP IB code for Special Function 44 7 132 is the total binary weight of bits 2 and 7 of the Status Byte EN is the HP IB code for ENTER d The conditions of the Extended Status Byte can t be enabled individually the desired conditions must be enabled with Special Function 44 9 3 42 HP 8970B e To set the conditions of the Extended Status Byte send the total binary weight of the bit posi tions desired The command sequence would be as follows RE36EN RE is the HP IB code for Special Function 44 9 36is the total binary weight of bits 2 and 5 of the Extended Status Byte EN is the HP IB code for ENTER Normally device subroutines for the Noise Figure Meter can be implemented simply by triggering measurements and then reading the output data In certain applications the controller must per form other tasks while controlling the Noise Figure Meter Figure 3 12 illustrates a flow chart for developing device subroutines using the instru ment s ability to issue the Require Service
379. rement Modes 1 5 through 1 9 to extend the frequency range of the Noise Figure Meter The plotter is connected to the System Interface Bus to give a permanent record of a noise figure or gain measurement The system interface bus address is the address of the System Interface Bus SIB connector on the back of the Noise Figure Meter This address only needs to be changed if some other instrument on the System Interface Bus has to use the default address that has been set up for the System Interface Bus The pass through device address is used in Pass Through Mode The pass through device address selects an instrument on the System Interface Bus that is going to be controlled by an external controller connected to the Hewlett Packard Interface Bus HP IB For more information on using Pass Through Mode and the pass through de vice address refer to the System Interface Bus Controi Detailed Operating Instruction The pass control address is the address of the controller that will alternate control responsibilities with the Noise Figure Meter The two instruments will alternate control on the System Interface Bus This is an advanced capability and does not need to be set under normal circumstances 3 113 Operation HP 8970B HP IB and System Interface Bus SIB Addresses conta Special Function 40 Description The HP IB and SIB addresses can be displayed and changed by Special Function 40 The selected address is displayed in decimal in t
380. rement Function 2 1 2 3 with Modes 1 2 or 1 7 Measurement Modes 1 2 or 1 7 Entry Error General Remedy Check and repeat entry Entered value is out of range Re enter new value 36 Vv Undefined special function Check then re enter correct special function code 37 V Cannot enter specified Select proper function that parameter allows entry of this parameter 38 V Noise Figure Test Set IF Refer to the Comments section at will be out of range the end of this instruction 39 V The number of plot points Change START FREQ STOP exceeds 251 FREQ or STEP SIZE to reduce the number of plot points below 251 Also refer to the Data Out put to Oscilloscopes Recorders and Plotters Detailed Operating Instruction GED HP B Errors General Remedy Check and repeat entry Undefined HP IB code Check then re enter correct HP IB code 4 Yy Invalid HP IB characters Check then re enter valid HP IB characters 42 NV System Local Oscillator not Refer to the Comments section at found on System Interface the end of this instruction Bus with 46 0 SP active 3 98 HP 8970B Operation Error Messages and Recovery contd Error Moma od omnino i paa a cont 44 45 46 47 48 GED HP IB Errors cont d Codes received while in Talk Only Mode 4 2SP Only send codes when the instru ment is addressed to listen Refer to the Comments section at the end of this instr
381. requency parameter will be accepted If an attempt to enter an out of range frequency is made the Noise Figure Meter displays one of the invalid frequency entry error messages i wee EE E HP 8970B Description cont d Predefined Program Listings gt Operation Programming The System LO cont d Special Function 42 e Special Function 42 5 is used to display and set the output signal power level of the system local oscillator The allowable range is 0 to 30 dBm If a level less than zero or greater than thirty is desired the auxiliary commands Special Function 42 0 need to be used to set the level Do not use Special Function 42 5 to exceed the minimum or maximum output signa power level limits of the local oscillator being used For Special Functions 41 0 through 41 4 Special Function 42 5 sets the command sequence prefix and suffix automatically as the power level 0 to 30 dBm is entered Special Function 41 5 custom local oscillator program requires that Special Function 42 6 be used with Special Function 42 5 The order is Special Function 42 6 then Special Function 42 5 f Special Function 42 6 is used only when the custom local oscillator Special Function 41 5 program has been selected Special Function 42 6 is used to properly format the command sequence that will set the output signal power level Special Function 42 6 is used to set the power prefix and suffix in place of Special Function 42 0 The prefix an
382. reset and HP IB Clear Conditions Special Function 0 9 Conditions E amp we 2 k Can be Stored and Recalled Function Key Stored in Con Calibration 33 1SP Attenuators IF Attenuators CI or Calibrate IF N N Off Off Off Table categories are explained in the Special Functions Detailed Operating Instruction Example Program Codes a gt Indications Comments Related Sections 3 68 LOCAL arenes COAG na me FUNCTION wmn Peers OOOD Hs i gt program codes The HP IB code for IF Attenuator Calibration is CI or 33 1SP During calibration the NOISE FIGURE display shows IF CAL IF Attenuator Calibration takes only a few seconds If for any reason the IF Attenuator Calibration is not successfully completed error E13 IF Attenuator Calibration failed is displayed Error code E26 is displayed if the IF Attenuator calibration data is not stored in the continuous memory Error E26 always occurs after an error E80 continuous memory failure Therefore an IF Attenuator calibration must always be performed after an error E80 has been cleared Either an HP 346B or HP 346C Noise Source is needed for calibrating the IF attenuators The HP 346A will work only with the addition of approxiimately 10 dB of gain at the calibration frequency of 30 MHz between the Noise Source and the Noise Figure Meter INPUT connector Error Messages and Recovery Special Functions HP 8970B
383. ress or a universal unlisten command is sent by the controller Data Input Format The Data message string or program string consists of a series of ASCII codes Each code is typically equivalent to a front panel keystroke in local mode Thus for a given operation the program string syntax in remote mode is the same as the keystroke sequence in local mode Example 1 shows a typical program string Program Codes All of the HP IB codes normally used by the operator to control the Noise Figure Meter are given in Tables 3 8 3 9 and 3 10 Table 3 8 provides an HP IB code to parameter sum mary Table 3 9 provides a special function to HP IB code summary Table 3 10 provides a front panel key to HP IB code summary All front panel keys except LOCAL have corresponding program codes Some functions have an additional code which terminates the numeric data entry in Hz rather than MHz as indicated on the front panel FA100MZFB1ISOMZSSiMZCA Calibrate Step Size set to 1 MHz 3 34 HP 8970B Operation gt Table 3 3 Message Reference Table 1 of 2 HP IB Related Commands Interface Applicable Response and Controls Functions Data Most Noise Figure Meter operations are bus pro AHI SHI grammable All measurement results special dis T5 TEO plays and error outputs are available to the bus L4 LEO Trigger If in remote and addressed to listen the Noise GET DTI Figure Meter makes a measurement ac
384. rogram codes 3 219 Programs Available to Control The System LO conta Special Function 41 Program For HP IB codes refer to Procedure Codes Comments A listing of the predefined programs is provided here for a quick reference A complete explanation of these programs and instructions on how to modify them are contained in the Programming the System LO Detailed Operating Instruction System LO Predefined Program Listings HP83408 83418 Custom System LO Commands 141 4 HP 86718 86724 HP 86738 C Local Oscillator Special Function 42 i Program 41 2 Program 41 3 Program 41 5 42 0 Auxiliary R 82 Commands 1 49 D 68 Special Function 42 1 is not used with Special Function 41 5 Refer to Special Function 42 7 30 ms 10 MHz Power Level 42 6 Power Prefix Power Suffix 3 220 pperenee HP 8970B HP 8970B Operation Programs Available to Control The System LO conta Special Function 41 Comments System LO Predefined Program Listings cont d cont d HP8340B 8341B Custom System LO Commands 41 4 or HP 86718 8672A HP 8673B C Local Oscillator Special Function 42 Dea Program 41 2 Program 41 3 Program 41 5 42 7 Frequency Prefix Frequency Suffix The HP 8673B Option 008 and HP 8673D Synthesized Signal Generators use K band amplifiers The amplifier is used when the output signal is greater than or equal to 16 GHz If either signal generator is being used as the system loca oscillator and the outp
385. rol the system local oscillator and the Noise Figure Test Set Measurement Mode 1 6 provides a means of increasing the frequency range of the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator from 18000 MHz to 99999 MHz This mode provides for a variable frequency user controlled local oscillator and a fixed IF If single sideband measurements are to be made a filter is used with the user controlled local oscillator and mixer Frequency conversion is not allowed for in the device under test DUT Although the signal measured at the Noise Figure Measurement System INPUT is always in the range of 10 to 18000 MHz the Noise Figure Meter uses the Excess Noise Ratio ENR of the noise source at the measurement frequency A typical DUT is an amplifier or transistor All of the Measurement Modes can be set up to use many of the other capabilities of the Noise Figure Meter For example each mode can make either UNCORRECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN measurements plus the measurements can be displayed on an oscilloscope or output to a recorder or plotter For an explanation and comparison of the ten Measurement Modes and instructions on how to choose the appropriate Measurement Mode and sideband operation refer to the Measurement Modes Detailed Operating Instruction The following minimum requirements are necessary for the Noise Figure Measurem ent System to operate in Measurement Mo
386. rvice per sonnel In the Service Manual Section VIII is a procedure for replacing the battery The part number of the Service Manual is on the title page of this manual If the instrument does not operate properly and is being returned to Hewlett Packard for service please complete one of the blue tags located at the end of this manual and attach it to the instrument Refer to Section II for packaging instructions 3 7 GENERAL OPERATING INSTRUCTIONS Before the Noise Figure Meter is switched on all protective earth terminals exten sion cords auto transformers and de vices connected to the instrument should be connected to a protective earth grounded socket Any interruption of the protective earth grounding will cause a potential shock hazard that could result in personal injury Before the Noise Figure Meter is switched on it must be set to the same line voltage as the power source or damage to the instrument may result 3 8 Turn On Turn on Procedures If the Noise Figure Meter is already plugged in set the LINE switch to ON If the power cable is not plugged in follow these instructions On the rear panel 1 Check the line voltage selection card for correct voltage selection 2 Check the fuse for correct current rating The current rating is printed on the line power module label 3 Plug in the power cable On the front panel set the LINE switch to ON HP 8970B Turn On cont d Turn on
387. s certified for temper ature range of 10 to 40 C For a noise source with an ENR of 14 to 16 dB For NF1 G1 gt 5 dB where NF1 is the noise figure of the device under test and G1 is the gain of the device under test For NF1 G1 gt 10 dB where NF1 is the noise figure of the device under test and G1 is the gain of the device under test Low noise external preamplification with net gain 30 dB 10 MHz to 1 6 GHz 1 6 to 2 4 GHz 2 4 to 12 GHz 12 to 15 GHz 15 to 18 GHz 10 MHz to 1 6 GHz 1 6 to 2 4 GHz 2 4to 18 GHz 1 Noise figure accuracy and gain accuracy are dependent on the device under test Refer to the Preamplifier Selection detailed operating instruction in Section II for more information on computing accuracy for your application 2 When making a measurement the Noise Figure Measurement System must be tuned in the same direction and to the same frequency points used during calibration without skipping any frequency points HP 8970B General Information Table 1 4 Noise Figure Measurement System Supplemental Characteristics Supplemental characteristics are intended to provide information useful in applying the system by giving typical but non warranted performance parameters Maximum Safe Input Level 20 dBm 0Vdc Maximum Operating input Power 20 dBm Maximum Net External Gain gt 60 dB Sensitivity 90 dB no external gain required but recommended to lower measurement uncertainty able t
388. s held down When the AUTO or SINGLE key is pressed the LED within the corresponding key lights to indicate that the instrument is in the sweep mode If the stop frequency is less than the start frequency the instrument sweeps downward The sweep is slower when it operates in this manner However calibration and plotting to an X Y recorder must be performed in ascending frequency order only Pressing the AUTO key starts a sweep at the current frequency ifthe current frequency is not outside the start stop range If the current frequency is outside the start stop range the auto sweep starts at the programmed start frequency To assure that an auto sweep starts at the programmed start frequency press START FREQ then AUTO HP 8970B Comments cont d Related Sections Operation Sweep cont d AUTO and SINGLE are toggle keys and they stop the sweep when pressed a second time However program codes W1 and W2 do not toggle over the HP IB Use program code W0 to stop a sweep over the HP IB Any front panel key except LOCAL DECREASE INCREASE SPECIAL FUNC TION NOISE FIGURE and NOISE FIGURE AND GAIN stop the sweep when pressed All HP IB codes except DE DECREASE Smoothing IN INCREASE Smoothing M1 UNCORRECTED NOISE FIGURE M2 CORRECTED NOISE FIGURE and oar and PT Pass Through Mode stop the sweep when given START FREQ STOP FREQ and STEP SIZE set the calibration parameters During calibration the maximum number o
389. s remain active and valid In remote the Noise Figure Meter can be addressed to talk or listen When addressed to listen the Noise Figure Meter can issue the Data and Status Byte mes sages Whether addressed or not the Noise Figure Meter responds to the Clear DCL Local Lockout Clear Lockout Set Local and Abort messages In addition the Noise Figure Meter can issue the Require Service Message Local to Remote Mode Changes The Noise Figure Meter switches to remote operation upon receipt of the Remote message The Remote message has two parts They are a Remote enable bus control line REN set true b Device listen address received once while REN is true When the Noise Figure Meter switches to remote the REMOTE annunciator on the front panel turns on 3 17 Local Mode Local Capability In local the Noise Figure Meter s front panel controls are fully operational and the instrument responds to the Remote message Whether addressed or not the Noise Figure Meter also responds to the Clear Local Lockout Clear Lockout Set Local and the Abort messages When addressed to talk the Noise Figure Meter can issue Data messages and the Status Byte message and whether addressed or not it can issue the Require Service message Remote to Local Mode Changes The Noise Figure Meter always switches to local from remote when ever it receives the Local message GTL or the Clear Lockout Set Local message The Clear Lockou
390. s the ENTER key is depressed ENR Table Entry Manual Measurement Functions Special Functions Temperature Units Selection mir SY UB Description Procedure Example Program Codes lt gt Indications Comments Related Sections TIM nanmam Uperation Store and Recall Up to ten instrument configurations can be stored in the Noise Figure Meter s storage registers Front panel settings that are stored and recalled are FREQUENCY FREQ INCR START FREQ STOP FREQ and STEP SIZE Table 3 14 Special Function Summary in the Special Functions Detailed Operating Instruction has a complete listing of special functions that can and cannot be stored and recalled Press STORE and a Data key a single digit 0 9 to identify the storage register Press RECALL and a Data key a single digit 0 9 to identify the storage register To recall an instrument configuration that has been stored in register 2 Function LOCAL keystrokes 2 gt program codes E cz STORE ST RECALL RC When the stored contents of a register are recalled the instrument configuration changes to the recalled parameter values If any key other than a digit is pressed after STORE or RECALL the store or recall entry will be rejected The data in the storage registers is not affected by PRESET or Special Function 0 0 When the Noise Figure Meter is turned off data stored in the registers is retained Preset Conditions and
391. se figure and gain measurement can be made CORRECTED WOISE FIGURE After calibration to measure corrected noise figure and gain press maae Note that the Noise Figure Meter removes its own noise figure from the measurement results Smoothing To change the number of measurements averaged to optimize speed of response and reduce jitter in the INSERTION GAIN and NOISE FIGURE displays press or SPECIAL FUNCTIONS Special Functions access capabilities of the Noise Figure Meter beyond those available with dedicated front panel keys Special Functions are selected in a Code SPECIAL FUNCTION format For example to display the ENR entry currently being used press CODE mammann SPECIAL FUNCTION Refer to the Special Functions Detailed Operating Instruction at the end of this section for more information 3 5 Operation HP 8970B Table 3 2 Detailed Operating Instructions Table of Contents Functional 1 of 2 Section Page Attenuation IF Attenuation Selection 3 117 RF Attenuation Selection 3 222 Calibration Calibrate a5 ssh ecsaner ge driaceccsweseeeees 3 59 Calibration Frequency 20cc000e 3 65 Calibration IF Attenuators 3 67 Calibration Input Gain Selection 3 69 Noise Figure Test Set YIG Filter Calibration serseri eara a eed 3 190 Displays Display Control cccccceeceeeues 3 81 Display Resolution 0 0c eeuee
392. set measurement frequency When using Special Function 2 1 an external filter is needed to eliminate the unwanted sideband c Special Function 2 2 offsets the measurement frequency to the system local oscillator frequency plus the IF in Measurement Modes 1 1 through 1 4 Special Function 2 2 offsets the measurement frequency to the user controlled local oscillator frequency plus the IF in Measurement Modes 1 6 through 1 9 The Noise Figure Meter uses the ENR value of the offset measurement frequency When using Special Function 2 2 an external filter is needed to eliminate the unwanted sideband d Special Function 2 3 offsets the measurement frequency to the IF frequency minus the system local oscillator frequency in Measurement Modes 1 1 through 1 4 Special Function 2 3 offsets the measurement frequency to the IF frequency minus the user controlled local oscillator frequency in Measurement Modes 1 6 through 1 9 The Noise Fir OY UB Description cont d TN GAMAN Operation Sideband Selection conta Special Functions 2 and 17 Figure Meter uses the ENR value of the offset measurement frequency Special Function 2 3 is useful for frequency upconversion characterization Special Function 17 is only used in Measurement Modes 1 5 through 1 9 With the exception of Measurement Mode 1 5 the measurement signal is converted twice The first conversion is done using an external mixer and the user controlled local oscillator The seco
393. splay Units Selection 00000 3 85 Sideband Selection 00 0c ccaeeeee 3 226 ENR Table Entry oss ceddeudadcdeweetecncecds 3 87 Smoothing Averaging 20005 3 230 Error Messages and Recovery 0006 3 93 Special Function Catalog 0 3 233 Fixed Frequency Increment 3 105 Special Functions ccc cceececees 3 235 Fixed Frequency Tuning 005 3 108 Spot ENR Thot Teold Fixed IF or LO Frequency Selection 3 110 and ENR Table Selection 3 254 HP IB and System Interface Bus SIB Store and Recall ci cece ccc cneceee 3 257 Addresses ousonsrosssossssesrsrors 3 113 Sweep obeos ese oaa a a a war eie iets 3 258 IF Attenuation Selection 3 117 System Interface Bus Control 3 262 Loss Compensation 2 eceeeeue 3 119 Temperature Units Selection 3 271 Manual Measurement Functions 3 121 Trigger Selection ccccccccccaceeece 3 273 Measurement Modes ccceececeee 3 125 Measurement Mode 1 0 0 0 00sec 3 132 Measurement Mode 1 1 cc cece cues 3 135 Section IV Measurement Mode 1 2 ceceee 3 140 PERFORMANCE TESTS Measurement Mode 1 3 0c cee e cues 3 145 Introduction si33 oie souk ceesde de hata xcs eecedwtes 4 1 Measurement Mode 1 4 ccccc cee eaee 3 150 Equipment Req
394. ssary for the user to refer to the instruc tion manual see Table of Contents for page references s Indicates hazardous voltages Indicates earth ground terminal a common ground exists between the unit under test and this instrument prior to energizing either unit The WARNING sign denotes a hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in per sonal injury Do not proceed be yond a WARNING sign until the indicated conditions are fully understood and met Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation If this instrument is to be energized via an auto transformer for voltage reduc tion make sure the common terminal is connected to neutral that is the grounded side of the mains supply The CAUTION sign denotes a hazard It calls attention to an operating procedure practice or the like which if not correctly per formed or adhered to could result in damage to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met Servicing instruction are for use by service trained personnel only To avoid dangerous electric shock do not perform any servicing unless qualified to do so Adjustments described in the manual are performed with power suppl
395. stem Interface Bus nce N Y N NC NC Of DC DP NC Off NC NC Off On i ie NC Off NC NC Off zz zZz 2k KZ ZZ ZZ NC NC Off Off iTable categories are explained in the Special Functions Detailed Operating Instruction 3 265 Operation Procedure cont d Example 3 266 HP 8970B System Interface Bus Control conta Special Functions 45 through 49 Special Function Program ode C Description code Noise Figure Meter is 49 6 N Off Off N Off Off the system controller Table categories are explained in the Special Functions Detailed Operating Instruction To select the Noise Figure Meter as the controller on the System Interface Bus tinuous Memory Speciat Function 8 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Lights Special Function Key Stored in Con Can be Stored and Recalled Perform a device clear on the System Interface Bus if the Noise Figure Meter is the active controller Perform an interface clear on the System Interface Bus if the LOCAL grm ie an aam FUNCTION memm eerste OOO Jes a gt program codes The following examples will illustrate how the Noise Figure Meter can share control of the System Interface Bus SIB with another instrument on the SIB and how the Noise Figure Meter can be configured to pass commands from a computer on the Hewle
396. sts HP 8970B PERFORMANCE TESTS GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST cont d Procedure coni d 4 12 Record the average of the voltmeter readings This is the reference voltage for the 5 dB and 10 dB attenuator calculations Vrefl NOTE When using the HP 3456A Digital Voltmeter s statistical math mode to calculate an average be sure to clear the math register before triggering the set of readings to be averaged Press MATH 0 to clear the register and then MATH 2 to enable math mode 8 On the Noise Figure Meter press 70 2 SPECIAL FUNCTION to switch in the inter 10 11 12 nal 5 dB attenuator Take 10 voltmeter readings Using at least four digits to the right of the decimal point calculate the average of the voltmeter readings On the HP 3456A Digital Voltmeter press MATH 0 to clear the math registers by turning math mode off MATH 2 to enable the statistical math mode and SINGLE to trigger 10 voltmeter readings When the voltmeter has finished taking the 10 readings press RECALL 0 to recall the average of the readings Record the average of the voltmeter readings Vavg 5 dB NOTE The limits for each attenuator are shown in linear units that ts as the ratio of measured voltages If an attenuator is outside its limits it may be defective Refer to Section VII in the Service Manual for trouble shooting information Compute the 5 dB attenuator value as shown Vrefi Vavg 5 dB ____
397. surement frequency of 20000 to 30000 MHz After the single sweep is completed the instrument halts 3 173 w pws LAVEN EA Program Codes indications Comments 3 174 Onoaratinn Ae Ue PV ae Measurement Mode 1 7 conta Special Function 1 7 The HP IB code for Measurement Mode 1 7 is E7 or 1 7SP Additional HP IB codes are given in the Comments section when using an external controller The left display shows each frequency at which a measurement is made and the EXT MIX annunciator lights The INSERTION GAIN display shows the gain ofthe DUT at the displayed frequency The NOISE FIGURE display shows the noise figure of the DUT at the displayed frequency An external controller can be used to control the Noise Figure Measurement System and the user controlled local oscillator in Measurement Mode 1 7 The following general conditions must be observed when using an external controller a The external controller and the user controlled local oscillator must be connected to the HP IB connector on the Noise Figure Meter b HP IB code H1 must be active c Special Function 4 0 normal talker and listener must be active Note that there is no HP IB code for this special function d Special Function 30 0 free run must be active HP IB code is TO e The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary
398. t Packard recommends that you periodically request the latest Manual Changes supplement The sup plement is identified with the manual print date and part number both of which appear on the manual title page Complimentary copies of the supplement are available from Hewlett Packard For information concerning a seria number prefix that is not listed on the title page or in the Manual Changes supplement contact your nearest Hewlett Packard office 1 6 DESCRIPTION 1 7 Noise Figure Meter The Hewlett Packard Model 8970B Noise Figure Meter together with an appropriate noise source automatically measures the noise figure and gain of the device to which it is attached The Noise Figure Meter can be tuned between 10 and 1600 MHz It can also be swept over all or any part of that range To measure the noise figure of devices with output frequencies greater than 1600 MHz an external mixer and local oscillator can be used to convert the frequency to the 10 1600 MHz range Measured noise can be displayed as noise figure equivalent input noise temperature or Y Factor Gain is displayed in dB Once calibrated a single keystroke of the Noise Figure Meter can automatically remove the mea surement system noise and gain contribution called second stage correction The Noise Figure Meter then displays only the noise figure and gain of the device under test DUT Five Excess Noise Ratio ENR tables four stored tables and one
399. t and the measurement system can lower system noise figure and therefore reduce the measurement uncertainty For more information refer to the Preamplifier Selection Detailed Operating Instruction Calibrate Display Units Selection Preset Conditions and Power Up Sequence 3 199 Description Procedure Example 3 200 Uperanon Power Measurements Specia Function 9 Special Function 9 measures noise power density in dB relative to 174 dBm Hz with the noise source on or off Either an approximate or a calibrated measurement can be made The value 174 dBm Hz was chosen because this is the thermal noise at 290K in a 1 Hz bandwidth This special function can be used to make absolute power density measurements or simply to verify that the measurement system setup is operating and the signal path is complete To exit from Special Function 9 press either UNCOR RECTED NOISE FIGURE or CORRECTED NOISE FIGURE AND GAIN To select a power density measurement key in the corresponding Special Function code and then press the SPECIAL FUNCTION key Special Functions 9 3 and 9 4 require that a calibration be performed prior to activating the special function If the calibration has not been performed error E20 not cali brated is displayed and the special function is not activated Since the power measurements can be performed from any Measurement Mode refer to the applicable Detailed Operating Instruction for the correct calibrati
400. t Set Local message sets the Remote En able control line REN false The Noise Figure Meter can also be switched to local by pressing the front panel LOCAL key assuming Local Lockout is not in effect 3 18 Addressing The Noise Figure Meter interprets the byte on the eight HP IB data lines as an address or a bus com mand if the bus is in the command mode The command mode is defined as attention control line 3 33 Operation Addressing cont d ATN true and interface clear control line IFC false Whenever the Noise Figure Meter is being addressed if in local or remote either the TALK or LISTEN annunciator on the front panel turns on The Noise Figure Meter s HP IB address is selected by special function To change the HP IB address or to determine the present address setting refer to the discussion titled HP IB and System Interface Bus SIB Addresses in the Detailed Operating Instructions at the end of this section Local Lockout When a data transmission is inter rupted which can happen by pressing the LOCAL key to return the Noise Figure Meter to local mode the data could be lost This would leave the Noise Figure Meter in an unknown state To prevent this a local lockout is recommended Local lockout disables the LOCAL key and allows return to local only under program control NOTE Return to local can also be accomplished by turning the Noise Figure Meter s LINE switch to OFF then back to ON How
401. t already been done f Set the user controlled loca oscillator to the frequency specified by Special Func tion 3 1 3 171 Mw pews 24 WAWES Example cont d 3 172 Omara ti nan AAA ked a u Measurement Mode 1 7 contd Special Function 1 7 powemee Code meem Function smmm ajag m FUNCTION GIGI o Rit HMQO Mitte OCMC i7 Si eD Ea OOO HOA E7B1LF35000MZFA20000MZFB30000MZSS200MZ Code re a Function Code Data Code Code Data Function Function Data Code Code Data Function g To calibrate the Noise Figure Measurement System and perform a Noise Figure Test Set Fine Tuning Calibration set up the equipment as shown below Ensure the user controlled local oscillator frequency is set before calibration PRESET enabled a fine tuning calibration Special Function 36 0 each time the Noise Figure Measure ment System is calibrated LOCAL keystrokes program codes SYSTEM LOCAL OSCILLATOR eIF THE PREAMPLIFIER AND FILTER ARE USED DURING THE MEASUREMENT THE FILTER IS USED WHEN A SINGLE SIDEBAND MEASUREMENT iS BEING MADE THEY MUST BE USED DURING CALIBRATION HP R07NR HP 8970B Example cont d Operation Measurement Mode 1 7 cont d Special Function 1 7 NOTE A Noise Figure Test Set Fine Tuning Calibration may need to be done separately from the measurement system calibration step h The separate fine tuning calibration is
402. t is external to the system or second local oscillator There is no frequency conversion in the device under test The frequency range in this mode is 10 to 18000 MHz b Measurement Modes 1 1 and 1 3 both require a variable frequency system local oscillator and an external mixer Measurement Modes 1 6 and 1 8 both require the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator external mixer and user controlled local oscillator The Noise Figure Meter can be used to control the system local oscillator Measurement Modes 1 1 and 1 3 and is used to contro the Noise Figure Measurement System Measurement Modes 1 6 and 1 8 The Noise Figure Meter controls the system local oscillator as directed by the system local oscillator program Special Function 41 or 42 Measure ment Modes 1 1 and 1 3 down convert the measurement frequency to 10 to 1600 MHz Measurement Modes 1 6 and 1 8 down convert the measurement frequency to 10 to 18000 MHz Measurement Modes 1 1 and 1 6 have no down conversion in the Device Under Test DUT for example an amplifier or transistor Measurement Modes 1 3 and 1 8 do provide for down conversion in the DUT for example a mixer or receiver c Measurement Modes 1 2 and 1 4 require a fixed frequency system local oscillator and an external mixer Measurement Modes 1 7 and 1 9 require the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system loc
403. t of the Noise Figure Test Set local oscillator mixer cables connectors and adapters CORRECTED NOISE FIGURE AND GAIN removes the measurement system noise contribution and allows only the noise figure and gain of the device under test to be displayed The Noise Figure Meter must be calibrated in the measurement frequency range and measurement mode before a corrected noise figure and gain measurement can be made To measure uncorrected noise figure press the NOISE FIGURE key To measure corrected noise figure and gain press the NOISE FIGURE AND GAIN key If the Noise Figure Meter is not correctly calibrated error code E20 will be displayed j Program Code Front Panel Key i gt NOISE FIGURE Mi N Active Active UNCORRECTED NOISE FIGURE AND GAIN M2 N Off Off CORRECTED Table categories are explained in the Preset Conditions and Power Up Sequence Detailed Operating Instruction tinuous Memory Can be Stored and Recalled Preset and HP IB Clear Conditions Special Function 0 9 Conditions Stored In Con zZz zZ To measure corrected noise figure and gain Measurement LOCAL CORRECTED keystrokes ANG GAIN Ga program codes For HP IB program codes refer to Procedure above When the instrument is making uncorrected noise figure measurements the UNCOR RECTED LED above the NOISE FIGURE key is illuminated The measurement result is displayed in the NOISE FIGURE display
404. t on the SIB needs only to be specified once b The external computer can now send commands to the instrument on the SIB After Pass Through Mode is set up using PTdEN the Noise Figure Meter has two addresses it s address and the pass through address The pass through address is one greater than the Noise Figure Meter s address if it is even and one less than the Noise Figure Meter s address if it is odd So if the address of the Noise Figure Meter is eight 8 then the pass through address would be nine 9 If the address of the Noise Figure Meter is seven 7 then the pass through address would be six 6 NOTE The pass through address can be displayed by pressing 40 7 SPECIAL FUNCTION In Pass Through Mode two addresses are used up on the Hewlett Packard Interface Bus HP IB Ensure that an address is not used twice c The external computer can send commands to a device on the SIB by using the Noise Figure Meter s pass through address Commands can be sent to the Noise Figure Meter by using the Noise Figure Meter s HP IB address For example if the external computer wanted to control the local oscillator on the SIB at address 19 and the Noise Figure Meter s address is eight 8 the external computer may send the following commands OUTPUT 708 PTI9EN This sets up the pass through device address OUTPUT 709 FRI0G00MZ iThis command is sent to the ipass through address and then ito the local os
405. t system local oscillator program must be active if the Noise Figure Meter is going to contro the system local oscillator The system local oscillator pro grams are listed below HP 8671B 8672A Synthesized Signal Generator Special Function 41 2 HP 8673B C Standard Synthesized Signal Generator Special Function 41 3 e HP 8340B 8341B Sweep Oscillator Special Function 41 4 e Custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or output power Use Specia Function 42 to define a new program for other system local oscillators h The user controlled local oscillator must be configured to produce the desired IF 10 to 18000 MHz i If a free running non synthesized source is being used as the system loca oscil lator a Noise Figure Test Set Coarse Tuning Calibration should have been done when the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator was put together The coarse tuning is ONLY required when a free running source is the system local oscillator or repairs have been made to the Noise Figure Test Set For more information on a Noise Figure Test Set Coarse Tuning refer to the Noise Figure Test Set YIG Filte
406. ta ENTER format Note that all frequency inputs from the front panel are in MHz Sweep Mode Selection Press the desired mode key AUTO or SINGLE to initiate a sweep To turn a sweep off press the active sweep mode key a second time Program Code Front Panel Key tinuous Memory Can be Stored Preset and HP IB Clear Conditions Special Function 0 9 Conditions and Recalled t S a m 3 da S AUTO SINGLE START FREQ STEP SIZE STOP FREQ 1600 MHz 1600 MHz Table categories are explained in the Preset Conditions and Power Up Sequence Detailed Operating Instruction 3 259 Operation Example Program Codes gt Indications Comments 3 260 HP 8970B Sweep cont d To sweep from 100 MHz to 400 MHz in 50 MHz steps once only LOCAL keystrokes E gt Codes Code Data Function program codes Function Data Code Code Data Function Program Code Hz HZ MHz MZ Sweep Off WO For additional HP IB program codes refer to Procedure above When the START FREQ or STOP FREQ key is pressed the left display shows the currently programmed start or stop frequency The instrument tunes to that frequency and continues measuring there As a new start or stop frequency is entered it appears in the left display When the STEP SIZE key is pressed the left display shows the step size only for as long as the key is held down A newly entered value is displayed for as long as the ENTER key i
407. te that there is no HP IB code for this special function e Special Function 30 1 trigger hold must be active HP IB code is T1 f The correct measurement parameters for example Measurement Mode frequen cies etc must be established Refer to Table 3 9 Special Function to HP IB Code Summary and Table 3 10 Front Panel Keys to HP IB Code Summary for applicable HP IB codes g Perform a triggered calibration with the DUT out of the measurement system refer to the Calibrate Detailed Operating Instruction h Set the Noise Figure Meter s calibrate function on HP IB code is CA i Set the system LO to the appropriate frequency Refer to the LO s operating manual for the required HP IB codes Allow sufficient settling time for the output of the LO to stabilize j Trigger a measurement using the HP IB code T2 Do not use the alternate HP IB code 30 2SP for it will be ignored k Amethod must be determined when to step to a new frequency and read the noise figure results This read operation cannot be completed until the new data is ready Itis possible to write an SRQ interrupt routine on the Data Ready status bit Refer to Enabling the Service Request Condition paragraph 3 30 HP 8970B HP 8970B Comments cont d Related Sections Operation Measurement Mode 1 1 conta Special Function 1 1 l Continue to loop through steps i j and k A method for determining when the calibration is completed must be
408. tep j completes the procedure for setting up the Noise Figure Meter for an oscilloscope display If a permanent record of the measurement results is required use an oscilloscope camera or perform the remain ing steps which provide a typical procedure for plotting the data onan X Y recorder and plotter 3 76 HP 8970B Operation Data Output to Oscilloscopes Recorders and Plotters conta Special Functions 7 8 and 20 through 25 Example Outputting Data to a Plotter on the System Interface Bus cont d NOTE The following Hewlett Packard plotters can be used with the Noise Figure Meter HP 9872B 7440A 7470A 7475A 7550A In general most Hewlett Packard plotters that use HP IB and support the common command core of HP GL will work with the Noise Figure Meter The maximum number of points that can be plotted is 251 If an attempt is made to plot more than 251 points error code E39 will appear when Special Function 25 X is entered to start the plot The maximum number of points is determined by the sweep START FREQ STOP FREQ and STEP SIZE Generally the number of points can be arrived at using the following equation STOP FREQ START FREQ i Number of plot points STEP SIZE STOP FREQ START FREQ If the fractional part of STEP SIZE does not equal 0 then add 1 k Connect the plotter to the SYSTEM INTERFACE BUS connector on the Noise Figure Meter l
409. ter Functions Lights Special Function Key Stored in Can tinuous Memory Can be Stored and Recalled Special Function 0 0 Conditions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Plot the grid with units title and curves Plot only the grid and annotation Plot only the data curves Select the Noise curve pen Select the Gain curve i pen Write the plot title for next plot Enable plotter commands on the System Interface Bus Enable plot data on the Hewlett Packard Interface Bus Table categories are explained in the Special Function Detailed Operation Instruction Example The following example shows how to set up the Noise Figure Meter to output a swept CORRECTED NOISE FIGURE AND GAIN measurement result to an oscilloscope and then to plot noise figure and gain results independently It is assumed that the Noise Figure Meter is already making this type of measurement in one of the Measurement Modes It is also assumed that the oscilloscope has A vs B or X Y capability Data Output to an Oscilloscope NOTE The oscilloscope must be an analog oscilloscope Digital oscilloscopes will not work with the Noise Figure Meter a Connect the Y AXIS X AXIS and Z AXIS outputs on the rear panel of the Noise Figure Meter to the A B and Z or horizontal vertical and Z inputs of the oscilloscope as appropriate Select the DC mode for all oscilloscope inputs 3 74
410. that 0 000 dB is shown in the left display If 0 000 dB is not shown press 0 and ENTER Press GAIN MAX Verify that 40 00 dB is shown in the left display If 40 00 dB is not shown press 40 and ENTER Operation HP 8970B OPERATOR S CHECKS Basic Functional Checks cont d Procedure 19 cont d 20 21 22 23 24 25 Press GAIN MIN Verify that 0 000 dB is shown in the left display If 0 000 dB is not shown press 0 and ENTER Press START FREQ Verify that 10 is displayed in the left display If 10 is not displayed key in 10 and press ENTER Press STOP FREQ Verify that 1600 is displayed in the left display If 1600 is not displayed key in 1600 and press ENTER Press STEP SIZE Verify that 20 is displayed in the left display If 20 is not displayed key in 20 and press ENTER Press CALIBRATE twice The Noise Figure Meter will perform a calibration from the start frequency to the stop frequency using the step size selected Press CORRECTED NOISE FIGURE AND GAIN Press SINGLE SWEEP Verify that the traces are along the bottom of the display Change the NOISE MAX and GAIN MAX limit to 2 Change the NOISE MIN and GAIN MIN limit to 2 Press SINGLE SWEEP The Noise Figure trace and Insertion Gain trace will appear in the center of the display FIXED FREQUENCY Tuning Check 26 27 28 Press the following keys to establish the tuned FIXED FREQUENCY parameters a FREQUENCY 500 ENTER b FREQ I
411. the Noise Figure Measurement System has not been factored out at the frequency point added Special Function 36 4 may be useful for an uncorrected noise figure measurement or as a way of re fine tuning a single frequency point 3 191 Operation Procedure 3 192 HP 8970B Noise Figure Test Set YIG Filter Calibration conta Special Functions 36 and 64 To select Special Functions 36 0 through 36 3 and 64 0 key in the special function code desired and press the SPECIAL FUNCTION key To select Special Function 64 1 press 64 1 SPECIAL FUNCTION select the frequency desired and press ENTER To use Special Function 36 4 press the FREQUENCY key and select the frequency desired Press ENTER Then press 36 4 SPECIAL FUNCTION Code ce oe oD FT Enable Fine Tuning 36 0 Calibration before Noise Figure Meas urement System Calibration is done Error E28 is enabled Disable Fine Tuning Calibration before Noise Figure Meas urement System Calibration is done Disable Fine Tuning Calibration before Noise Figure Meas urement System Calibration is done Also error twenty eight is disabled Perform a Fine Tun ing Calibration from START FREQ to STOP FREQ and enable Special Function 36 1 Enable a Fine Tun ing Calibration at the current frequency Enable a Coarse Tun ing Calibration Set the upper fre quency limit of the Noise Figure Test Set iTable categories are explai
412. the SYSTEM INTERFACE BUS connector and is controlled by the Noise Figure Meter The System Local Oscillator is used for frequency conversion in Measurement Modes 1 1 through 1 4 and is part of the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and System Local Oscillator in Measurement Modes 1 5 through 1 9 User Controlled Local Oscillator The User Controlled Local Oscillator is ONLY used in Measurement Modes 1 6 through 1 9 The User Controlled Local Oscillator is used for frequency conversion This LO must be controlled by the user the Noise Figure Meter doesn t control the User Controlled Local Oscillator The User Controlled Local Oscillator is never connected to the SYSTEM INTERFACE BUS connector The ten Measurement Modes can be divided into the following three subsets a Measurement Mode 1 0 is a stand alone mode with no externa mixer or system local oscillator required and no frequency conversion in the device under test The frequency range in this mode is 10 to 1600 MHz Measurement Mode 1 5 is similar to Measurement Mode 1 0 Measurement Mode 1 5 requires the use of the HP 8971B Noise Figure Test Set and a system local oscillator The Noise Figure Meter Noise Figure Test Set and system local oscillator form the HP 8970S Noise Figure Measurement System The Noise Figure Meter controls the Noise Figure Test Set and the system local oscillator This mode does not require the use of an external mixer tha
413. the count characters are in decimal they are entered as they are For an example of using the custom local oscillator program and Special Function 42 7 refer to Example two 2 at the end of this instruction o 3 215 Procedure contd 3 216 Operation Programming The System LO conto Special Function 42 Modified data can be entered in any order For example the settling time can be modified prior to changing the frequency prefix and suffix Running the System LO Program Before the program can be run several conditions must be met a The system local oscillator must be connected to the Noise Figure Meter s SYSTEM INTERFACE BUS connector with an HP IB cable b Special Function 48 0 active Noise Figure Meter is the system controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 46 0 active Enable local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 d The address of the system local oscillator must match the system local oscillator address that is stored in the Noise Figure Meter Use Special Function 40 1 system local oscillator address to display and change the address if necessary e Select the proper measurement mode 1 1 through 1 9 f The internal sweep of the system LO if one exists should be off Once the above conditions are met the system LO progr
414. the following equation G i Fao smp sys I TE Famp sys Pre Famp 100 1 Goreamp 10 4 99 Greemp 6 Goreamp 16 5 linear 24 3 dB A preamplifier with 24 3 dB or greater of gain and 6 dB or less of noise figure will be needed to reduce the measurement system noise figure to a level where it minimizes measurement uncertainty 3 204 HP 8970B Description Uperation Preset Conditions and Power Up Sequence Includes Special Functions 0 0 and 0 9 Power Up When first turned on the Noise Figure Meter performs a sequence ofinternal checks after which the instrument is ready to make measurements During the power up sequence all front panel indicators light for approximately two seconds to allow the operator to determine if any are defective Then Ctr appears in the INSERTION GAIN display and on or OFF appears in the NOISE FIGURE display Ifthe Noise Figure Meter is the System Interface Bus controller Special Function 48 0 on will be displayed If the Noise Figure Meter is not the System Interface Bus controller Special Function 48 1 OFF will be displayed Next Fr appears in the INSERTION GAIN display and CAL appears in the NOISE FIGURE display for approximately five seconds while the Noise Figure Meter performs a frequency calibration When the frequency calibration is completed the Noise Figure Meter restores the same configura tion it had before the power was removed Exc
415. the plot is aborted Hitting a front panel key also aborts the plot When Special Function 47 1 is selected and a plot is started the Noise Figure Meter s front panel will display Plot If data is not read from the Noise Figure Meter the front panel will continue to display Plot until data is read the Noise Figure Meter receives an HP IB command or a front panel key is pressed 3 78 PNXee 2 ie ee TIT namant rir ov ivp Vperation Data Output to Oscilloscopes Recorders and Plotters conta Example cont d TEE ONAMAT Special Functions 7 8 and 20 through 25 v The following program example shows how to get data from the Noise Figure Meter to the controller and from the controller to the plotter NOTE The program assumes that the address of the Noise Figure Meter is set to eight and the plotter address is set to five Also it is assumed that a measurement has been made and now it is desired to plot the data This program was written in BASIC language 3 0 using the HP 9000 Series 200 Model 236 computer 10 DIM A 30000 Setup a large string for the plot data 20 OUTPUT 708 PM Read plot data on HP IB 30 OUTPUT 708 PA Start the plot 40 ENTER 708 A Get the plot data 50 OUTPUT 705 A Send data to plotter at address 5 60 END w The plotted traces should be the same as the traces that were displayed on the oscilloscope Piotting Data on an X Y Recorder x Connect the X AXIS
416. then execute a single measurement and return to trigger hold Function LOCAL oin Gee FUNCTION SPECIAL FUNCTION keystrokes lt i gt program codes 3 273 Operation Program Codes gt indications Comments Related Sections 3 274 HP 8970B Trigger Selection conra Special Function 30 For HP IB codes refer to Procedure When Special Function 30 0 is active the front panel displays update continuously When Special Function 30 1 is active the front panel displays do not change When Special Function 30 2 is active the Noise Figure Meter makes one measurement and then returns to the last selected trigger mode When performing a triggered calibration only the HP IB mnemonic code T2 can be used The Noise Figure Meter does not respond to the alternate 30 2SP code Calibrate Measurement Modes 1 0 through 1 9 Smoothing Special Functions HP 8970B Performance Tests SECTION IV PERFORMANCE TESTS 4 1 INTRODUCTION The procedures in this section test the HP 8970B s electrical performance using the specifications of Table 1 1 as the performance standards All tests can be performed without access to the interior of the instrument These tests in conjunction with the performance tests of the HP 8971B Noise Figure Test Set System Local Oscillator and Noise Source verify the performance of the HP 8970S Noise Figure Measurement System NOTES Unless otherwise noted no warm
417. thmetic averaging is used during swept operation Rear Panel Qutputs X Axis and Y Axis from 0 to 6V Z Axis is TTL for pen lift on an X Y recorder and blanking on an oscilloscope Piotter Capability Noise figure and gain versus frequency plot with grid title and noise figure gain and frequency axis annotation Compatible Digital Plotters HP 7470A 7475A 7550A 7440A and 9872B 1 7 General Information HP 8970B Table 1 3 Noise Figure Measurement System Specifications Figure Measurement System Specifications for the Noise Figure Measurement System are the same as the Noise Figure Meter with the following exceptions These specifications are valid when any of the recommended system local oscillators HP 8671B HP 8672A HP 8673B standard HP 8673C HP 8340A B or HP 8341A B is used in the Noise Characteristics Performance Limits Conditions NOISE FIGURE MEASUREMENT Range Instrumentation Uncertainty GAIN MEASUREMENT Instrumentation Uncertainty iNPUT Frequency Range Reducing System Noise Figure with Preamplification Noise Figure maximum SSB1 SSB2 SSB3 Input SWR GENERAL Power net weight and dimensions 0 to 30 dB lt 0 25 dB lt 0 45 dB Tunable from 10 to 18000 MHz lt 2 dB noise figure of the external system 12 dB 0 003 dB MHz lt 21 dB 22 dB lt 24 dB 28 dB 1 7 1 2 1 2 1 Sum of HP 8970B HP 8971B and local oscillator All specification
418. tion to convert Trot in Kelvins to ENR is ENR 10 log Tho 290 1 f Special Function 5 5 enables display and entry of the noise source identifier Up to five digits within the range of 0 to 60000 can be used to identify the noise source For example the serial number of the noise source for which the ENR table data was entered can be used g Special Function 5 6 enables display of the noise source catalog The noise source catalog special function allows the user to examine each of the ENR tables the user is able to see how many entries are in each table h Special Function 5 7 allows display and entry of the ENR table that will be used for calibration Tables 0 through 4 can be selected for a calibration Special Function 5 7 is useful in Measurement Modes 1 3 1 4 1 8 and 1 9 where two noise sources may be required i Special Function 5 8 allows display and entry of the ENR table that will be used for a measurement Tables 0 through 4 can be selected for the measurement j Special Function 6 0 enables entry of a value for Trois Thot and Tog are used for hot cold manual measurements The allowable values for Teo in Kelvins range from 0 to 9999 To enable use of the ENR table data or spot ENR data or to display the current ENR or noise source catalog key in the corresponding Special Function code and then press the SPECIAL FUNCTION key To display and enable entry of spot ENR Thot Toota the noise source identifie
419. tions Preset and HP IB Clear Conditions Special Function 0 9 Conditions Less resolution on NOISE FIGURE display Less resolution on INSERTION GAIN display Table categories are explained in the Special Function Detailed Operation Instruction 3 83 Uperanon Hr Oy Ub Display Resolution conta Inciudes Special Function 12 Example To have less resolution in the NOISE FIGURE display LOCAL ame COKE seman pos FUNCTION smn peers OWO oj Ci program codes Program For HP IB program codes refer to Procedure above Codes Indications The NOISE FIGURE and INSERTION GAIN displays reflect the resolution corres ponding to the selected Special Function Comments Special Function 12 also affects the resolution of the HP IB output The HP IB output always has one digit more of resolution than the front panel displays Related Display Units Selection Sections Special Functions 3 84 MN NANAMAN HP 8970B Description Procedure Example Program Codes indications Comments Operation Display Units Selection Special Function 10 Noise measurements can be output in the following display units a noise figure in dB F dB b noise figure as a ratio F c Y factor in dB Y dB d Y factor as a ratio Y e equivalent input noise temperature in kelvins Te K To select a NOISE FIGURE display unit key in the corresponding Special Function code and then press the SPECIAL FUNCTION key S
420. to the instrument rack using the flange kit Order HP part number 5061 9677 1 12 Rack Flange and Front Handle Combination Kit Option 909 This is not a front handle kit and a rack flange kit packaged together it is composed of a unique part which combines both functions Order HP part number 5061 9683 1 13 HEWLETT PACKARD gt INTERFACE BUS 1 14 Compatibility The Noise Figure Meter is compatible with HP IB to the extent indicated by the following code SH1 AH1 T5 TEO L4 LEO SR1 RL1 PPO DC1 DTI C0 and El The Noise Figure Meter interfaces with the bus via open collector TTL circuitry An explanation of the compatibility code can be found in IEEE Standard 488 1978 IEEE Standard Digital Interface for Programmable Instrumenta tion or the identical ANSI Standard MC1 1 For more detailed information relating to program mable control of the Noise Figure Meter refer to Remote Operation Hewlett Packard Interface Bus in Section IH of this manual 1 15 Selecting the HP IB Address The Noise Figure Meter can use two HP IB addresses One is the address of the Noise Figure Meter The second is the HP IB address of the Noise Figure Meter when it is in Pass Through Mode Pass Through Mode allows commands to be passed through the Noise Figure Meter from a computer on the HP IB to an instrument on the SIB Refer to the HP IB and System Interface Bus SIB Addresses Detailed Operating Instruction in Section
421. to 1600 MHz Wiltron 60N50 P Directivity 40 dB Wideband Frequency Range 0 1 to 1300 MHz HP 8447D Option 010 Amplifier I Gain 26 dB Output Power for 1 dB Gain Compression 7 dBm Frequency Range 0 1 to 1300 MHz Gain 48 dB Output Power for 1 dB Gain Compression gt 15 dBm Wideband Amplifier H HP 8447F Option 010 C Operator s Checks P Performance Tests A Adjustments T Troubleshooting 1 11 1 12 HP 8970B Installation SECTION II INSTALLATION 2 1 INTRODUCTION This section provides the information needed to install the Noise Figure Meter Included is informa tion pertinent to initial inspection power require ments line voltage selection power cables inter connection environment instrument mounting storage and shipment In addition interconnect information for the Noise Figure Measurement System is provided 2 2 INITIAL INSPECTION To avoid hazardous electrical shock do not perform electrical tests when there are signs of shipping damage to any portion of the outer enclosure covers panels meters Inspect the shipping container for damage If the shipping container or cushioning material is dam aged it should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechanically and electrically The contents of the shipment should be as shown in Figure 1 1 Procedures for checking electrical p
422. tor Special Function 46 or the plotter Spe cial Function 47 The Noise Figure Meter has the capability of sharing control responsibilities with another instrument on the System Interface Bus Special Function 49 deals with passing control between controllers on the System Interface Bus and control of the System Interface Bus The Noise Figure Meter can be configured to the following Special Function 49 conditions e Special Function 49 0 do not pass control automatically Special Function 49 1 pass control automatically Special Function 49 2 release contro of the SIB Special Function 49 3 take control of the SIB Special Function 49 4 perform a serial poll on the SIB e Special Function 49 5 perform a selective device clear of the pass through device Special Function 49 6 perform a device clear on the SIB if the Noise Figure Meter is _ the active controller e Special Function 49 7 perform an interface clear on the SIB if the Noise Figure Meter is the system controller The structure of the System Interface Bus requires that one and ONLY one instrument be the system controller on the SIB As called out in the IEEE 488 1 specification The system controller is defined as the device that controls the REN and IFC lines on an IEEE 488 1 interface Special Function 48 conveys to the Noise Figure Meter if it will be the system controller Special Function 48 0 or if the Noise Figure Meter will not be the s
423. tor and not to the HEWLETT PACKARD INTERFACE BUS connector If the Noise Figure Meter is not going to control the Noise Figure Test Set Special Function 45 2 can be selected to avoid E44 The next time it is desired for the Noise Figure Meter to control the Noise Figure Test Set Special Function 45 0 or 45 1 will have to be selected Error code E45 is generated when the plotter is not found at the address specified by Special Function 40 3 Verify that the plotter is connected to the SYSTEM INTER FACE BUS connector and not to the HEWLETT PACKARD INTERFACE BUS connector Also verify that the address of the plotter is the same as the address specified by Special Function 40 3 Error code E46 is generated when the pass through device is not found at the address specified by Special Function 40 6 or HP IB code PT Verify that the pass through device is connected to the SYSTEM INTERFACE BUS connector and not to the HEWLETT PACKARD INTERFACE BUS connector Also verify that the address of the pass through device sent with the PT command is the valid address of the pass through device on the System Interface Bus The address specified with Special Function 40 6 must be the same as the address sent with the PT command Error code E47 is generated when the Noise Figure Meter expects to find a controller on the System Interface Bus and the controller is not found Error E47 could be caused by Special Function 49 1 being ena
424. tor lights b The frequency is swept from the start frequency 123 MHz to the stop fre quency 789 MHz in 40 MHz steps This sweep is performed three times c After calibration is complete the CALIBRATE annunciator turns off and the CORRECTED NOISE FIGURE AND GAIN annunciator lights d The INSERTION GAIN display shows approximately 0 dB and the NOISE FIGURE display shows approximately 0 FdB Press SWEEP SINGLE Verify that the key s LED lights The established fre quency range is swept once After the sweep is completed the LED turns off and the left display shows 789 MHz Press SWEEP AUTO Verify that the key s LED lights and the frequency range is swept repetitively Press SWEEP AUTO again Verify the sweep stops at the current frequency and the LED goes off Press SMOOTHING INCREASE four times to set the smoothing averaging factor to 16 Press SWEEP SINGLE Verify that the INSERTION GAIN and NOISE FIGURE displays are more stable and the time required for each measurement is longer Press SMOOTHING DECREASE four times to return the smoothing factor to 1 GRAPHIC SCALE Check 14 15 16 17 18 Verify that the display is set up as described in steps 3 through 5 Press 7 0 SPECIALFUNCTION This will enable Noise Figure and Insertion Gain to be seen on the display Press NOISE MAX Verify that 8 000 dB is shown in the left display If 8 000 dB is not shown press 8 and ENTER _ Press NOISE MIN Verify
425. tt Packard Interface Bus HP IB to an instrument on the SIB Pass Through Mode Pass Through Mode will allow commands to be passed through the Noise Figure Meter from an external computer on the Hewlett Packard Interface Bus HP IB to an instrument on the System Interface Bus SIB The instrument on the SIB can be a listener or a talker An SRQ Service Request on the SIB can trigger an SRQ on the HP IB Special Function 49 4 can be used to do a serial poll of an instrument on the SIB Parallel poll will not be supported HP 8970B Operation System Interface Bus Control conta Special Functions 45 through 49 Example NOTE cont d When in Pass Through Mode the rate at which data is sent or received is slowed down Typically data is sent at a rate of 0 5 ms byte and received atarate of 1 6 ms byte This is five and eight times respectively slower than if the instrument were connected directly to the external computer Pass Through Mode is set up as follows a When the external computer wants to communicate with an instrument on the SIB it sends the command PTdEN dis the address of the instrument on the SIB that the computer wants to communicate with The Noise Figure Meter will also accept the command PTd carriage return line feed to be compatible with the HP 8757A Scalar Network Analyzer NOTE The command PTdEN does not have to be sent each time a command is sent to the instrument on the SIB The instrumen
426. tters c All other characters are ignored however they can not be used as the second character of a two character HP IB program code If any of these other characters are used as a second char acter or if an undefined combination of valid characters is sent SRQ is set if the HP IB error condition has been enabled Turning Off Functions When operating in local mode CALIBRATE and SINGLE and AUTO Sweep toggle on and off with successive key strokes In remote mode these functions do not toggle on and off Instead both require that the HP IB code WO be used to turn off the function Programming Numeric Data When programming tuned frequency or issuing any numeric data other than specific HP IB codes to the Noise Fig ure Meter certain precautions should be observed Numeric data may consist of up to five digits one decimal point and a one digit signed exponent Triggering Measurements with the Data Message A feature that is available from both the front panel and via remote programming is the selection of free run standby or triggered operation of the Noise Figure Meter The HP IB codes and related Special Functions are discussed in detail in the Trigger Selection Detailed Operating Instruction later in this section 3 21 Sending The Data Message Depending on how the control functions are set the Noise Figure Meter can either talk only or talk and listen both normal operation If set to both Operation talk a
427. tus tb uv du it ue tet HP IB Code Parameter oem Special Function Catalog cont d Line 7 Status Line 8 Status Display and Enter Pass Control System Interface Bus Address Display and Enter Plotter System Interface Bus Address Display and Enter System Interface Bus Address Display and Enter Noise Figure Test Set System Interface Bus Address Hz HP IB Data Output NOISE FIGURE Display Only Left INSERTION GAIN and NOISE FIGURE Displays During Calibration the Frequency Calibration Data GKB and Second Stage Temperature are output IF for Modes 1 1 1 3 1 6 and 1 8 IF Attenuator Hold INCREASE Smoothing Perform an Interface Clear on the System Interface Bus if the Noise Figure Meter is the System Controller IF Attenuation Selection Auto 0dB 5 dB 10 dB 15 dB 20 dB 25 dB 30 dB 35 dB System LO Programs HP 8350B Sweep Oscillator HP 8671B 8672A Syn Signa Generator HP 8673B Syn Signal Generator HP 8340B Sweep Oscillator Custom Local Oscillator Program Keyboard Test Display Key Codes Key Test Row 1 Key Test Row 2 Key Test Row 3 HP 8970B HP IB Code Operation x gt Table 3 8 Noise Figure Meter HP IB Code to Parameter Summary 3 of 4 Parameter Key Test cont d Key Test Row 4 Key Test Row 5 Key Test Row 6 Key Test Row 7 Key Test Row 8 Loss Compensation before DUT Loss Compensation after DUT Disable System LO on System Inter face Bus En
428. uction Noise Figure Test Set not found when 45 0 SP or 45 1 SP is active Refer to the Comments section at the end of this instruction Plotter was not found on the System Interface Bus at the address specified by 40 3 SP Refer to the Comments section at the end of this instruction Pass through device not found on the System Inter face Bus or 40 6 SP set incorrectly Noise Figure Meter did not find a controller on the Sys tem Interface Bus while passing control If the Noise Figure Meter pass control capability Special Func tion 49 1 is not being used select Special Function 49 0 Also refer to the comments section at the end of this instruction Refer to the Comments section at the end of this instruction Two or more controllers are on the System Interface Bus Service Errors 60 79 NV Service related errors Refer to Service Related Errors in Section VIH Service NV Continuous memory failure Refer to Comments below Noise Figure Test Set Errors 100 101 102 Vy Noise Figure Test Set fine Reduce the number of points by tune table will overflow changing the START FREQ STOP FREQ or STEP SIZE then perform a fine tune calibration NV Noise Figure Test Set Refer to Section VIL Service and self test failed Special Function 98 7 NV Auto sweep was aborted to Start sweep again with SWEEP AUTO key Also refer to comments
429. uency calibration Completion of Frequency Calibration does not set the CALIBRATION COMPLETE bit of the HP IB statue byte That bit is used only for RF calibration Special Function 31 is defined as follows a 31 0 Selects the automatic frequency calibration mode In addition to the initial frequency calibration described previously a frequency calibration is automatically initiated 15 minutes after power on 30 minutes later 1 hour later 2 hours later and then every 2 hours until the instrument is turned off or a different 31 Special Function is entered This mode is the default condition b 31 1 Disables the frequency calibration In this mode frequency calibration is still done if the PRESET key is pressed However frequency calibration is not initiated periodically as described in 31 0 c 31 2 Initiates a frequency calibration immediately After that frequency calibra tion the operation returns to the mode active when 31 2 was entered If 31 1 was active it remains active after the frequency calibration is done Frequency calibration is performed as a part of PRESET Frequency calibration can also be done when the CALIBRATE key is pressed and Special Function 31 0 is active In addition the frequency calibration can be performed or disabled by keying in the corresponding Special Function code and then pressing the SPECIAL FUNCTION key 3 65 Operation Procedure cont d Example Program Codes a
430. uired 0 cece ee eceeee 4 Measurement Mode 1 5 cee eee ees 3 155 Test Record o5 50 80is clone duh sw cawen ies te a sa 4 1 Measurement Mode 1 6 launuan 3 160 Calibration Cyele 6 02sccseesseesverscenes s 4 1 Measurement Mode 1 7 cceeeeeees 3 168 Tuning Accuracy Performance Test 4 2 Measurement Mode 1 8 02000 3 176 Input SWR Performance Test 0 0000 4 4 Measurement Mode 1 9 0 0ceeue 3 183 Noise Figure Range and Accuracy Noise Figure Test Set YIG Filter Performance Test ccc cccccaccccccccees 4 6 C librahon 4 ci s ca scwce cs ienne wake 3 190 Gain Measurement Uncertainty Noise Figure Uncorrected and Noise Performance Test ccccccccccccccece 4 10 Figure and Gain Corrected 4 3 198 Instrument Noise Figure Performance Test 4 19 Power Measurements cccceceeeee 3 200 Spurious Response Performance Test 4 20 Preamplifier Selection cc00eceeee 3 202 Jitter Performance Test 000 c cee eeees 4 22 ILLUSTRATIONS Figure Page Figure Page 1 1 HP 8970B Accessories Supplied 3 3 GAIN MAX GAIN MIN NOISE MAX and and Options 907 908 and 909 10 NOISE MIN Features 0 005 3 9 3 4 LINE Switch PRESET and 2 1 Line Voltage and Fuse Selection 2 2 SOURCE Features 0 ccccsc0ee 3 10 2 2 Power Cable and Mains Plug Part 3 5 SWEEP and FIXED F
431. unction 64 1 is useful if the system local oscillator doesn t go to 18000 MHz With Special Function 64 1 the Noise Figure Test Set can be calibrated to the nearest 500 MHz of the upper frequency limit desired NOTE If the system local oscillator doesn t go to 18000 MHz Special Function 64 1 MUST be used If Special Function 64 1 isn t used error code E19 Noise Figure Test Set Calibration Failed will be generated Fine Tuning Calibration Special Function 36 Fine tuning calibration is used to align the passbands of the Noise Figure Meter and Noise Figure Test Set at the measurement frequencies defined by START FREQ STOP FREQ and STEP SIZE Fine Tuning Calibration is required when the Noise Figure Test Set is in single sideband operation Special Function 17 0 and the measurement frequency is greater than 2400 MHz SSB3 There is no limit to the number of times that a Fine Tuning Calibration may be performed The Noise Figure Measurement System will perform better the more fre quently a Fine Tuning Calibration is done However once the Fine Tuning Calibration is done a new Fine Tuning Calibration should not be required unless the Noise Figure HP 2ga7nR HP 8970B Operation Noise Figure Test Set YIG Filter Calibration conra Description cont d Special Functions 36 and 64 Test Set is turned off the ambient air temperature around the Noise Figure Test Set changes by more than 5 C since the last Fine Tuning Ca
432. ure Meter Measurement Modes 1 1 through 1 4 or the IF into the Noise Figure Test Set Measurement Modes 1 5 through 1 9 Special Function 16 1 is particularly useful in Measurement Modes 1 2 and 1 7 In these modes the left display normally displays the measurement frequency before it has been down converted With Special Function 16 1 the IF into the Noise Figure Meter or Noise Figure Test Set is displayed Special Function 16 2 blanks the left frequency display In this mode parameters being displayed or changed are shown in the left display until the ENTER or FREQUENCY key is pressed When the START FREQ or STOP FREQ key is pressed the start and stop frequencies are displayed Once the start and stop frequencies have been entered press the FREQUENCY key to blank the left display again The left display is blank during a SINGLE or AUTO sweep Special Function 16 3 blanks all the front panel displays The displays are not updated The message dISP Offis displayed in the right displays The Noise Figure Meter runs slightly faster in this mode To select one of the Display Control special functions key in the special function desired and then press the SPECIAL FUNCTION key Special Function Program Code Description Code i gt Measurement frequency is displayed Input IF is displayed Measurement frequency is not displayed Front panel displays are disabled Lights Special Function Key Stored in Con tinuous Memory Can
433. ure within the specified range and press the ENTER key Up to five digits are allowed for temperature entries If a minus sign is used only four digits are allowed The maximum resolution is to three places to the right of the decimal point 3 271 Operation Example Program Codes lt gt Indications Comments Related Sections 3 272 HP 8970B Temperature Units Selection conta Special Function 11 To enter a value of 75 F for Twoa eam COKE sm Function OOO gm cIa ele GIG D2T C75EN Code _ Teneo Function Code ieee Data Function ENTER game Data ama LOCAL keystrokes lt a gt program codes For HP IB codes refer to Procedure above When temperature data has been entered correctly the selected unit appears in the left display The equations used to convert from one temperature unit to another are C 273 15 OF 9 5 C 32 ENR Table Entry Loss Compensation Special Functions Spot ENR Thon Ton and ENR Table Selection HP 8970B Description Procedure Example Operation Trigger Selection Special Function 30 Special Function 30 0 selects free run triggering for continuous measurements Special Function 30 1 selects trigger hold to prevent continuous measurements When trigger hold is active the frequency and results of the last measurement are held and displayed No additional measurements are made
434. ure Meter Supplemental 3 6 Response to a Clear Message or Characteristics 64400 ddan sew nsaeacas 1 7 Pressing PRESET 2265 1 3 Noise Figure Measurement 3 7 Service Request Enabled Conditions System Specifications 6 000 1 8 Summary es ead s5 okt ences Cese ee ee ks 1 4 Noise Figure Measurement System 3 8 Noise Figure Meter HP IB Code to Supplemental Characteristics 1 9 Parameter Summary ecen eee 1 5 Recommended Test Equipment 1 10 3 9 Special Function to HP IB Code 3 10 Front Panel Keys to HP IB Code 2 1 Noise Figure Meter Factory Summary sasasessrresonressreresereese i Set Addresses c cccccereeececes 2 3 3 11 Commonly Used Code Conversions 2 2 ASCII Address Codes to Decimal 3 12 Front Panel Summary 08 Equivalents 22s iit cie nent eack eee 2 3 3 13 Special Function 0 9 and Preset Default Values for Special Functions 3 1 Operating Characteristics 3 3 3 14 Special Function Summary 3 2 Detailed Operating Instructions Table of Contents Functional 0 3 6 4 1 IF Attenuator Values 0c0ee 3 3 Message Reference Table 3 35 4 2 Performance Test Record 5 3 4 Functions Not Programmable Via TEE OL ces egy eaihabice cata een e an ai 3 36 HP 8970B Safety Considerations SAFETY CONSIDERATIONS GENERAL
435. ure Meter uses internal IF attenuator values for measuring gain Prior to performing the Gain Measurement Uncertainty Performance Test the IF attenuators are calibrated to ensure valid gain measurements For the IF attenuator calibration the IF attenuators are measured by taking a reference power reading switching in an attenuator and then taking another power measure ment The relative power change is equal to the IF attenuator value The power change is calculated using a voltmeter to measure the change in voltage from the Recorder Output of the power meter The attenuator values are computed as the ratio of measured voltages linear units rather than in decibels logarithmic units The linear value of the 15 dB attenuator is calculated by multiplying the linear value for the 10 dB attenuator and the linear value for the 5 dB power change observed when the attenuators change from 10 to 15dB The 25 dB attenuator is calculated in the same way using the 20 dB instead of the 10 dB attenuator value The calibrated IF attenuator values are recorded in Table 4 1 and entered into the Noise Figure Meter For the Gain Measurement Uncertainty Performance Test net gain is generated by removing attenuation from a high gain setup The net gain is alternately measured first by a power meter and then by the Noise Figure Meter The two measurements should compare to within 0 15 dB NOTES This test is difficult to perform Passing the test requires minimum
436. urned off for example Power Measurements The following four Special Functions are not affected by either the Clear message or by press ing PRESET These four Special Functions are affected by Special Function 0 9 For the default values of these four Special Functions refer to Table 3 14 Special Function Summary in the Special Functions Detailed Operating Instruction a Control Function Selection Special Function 4 b HP B Addresses Special Function 40 c System LO Programs Special Funtion 41 d System LO Commands Special Function 42 In addition Service Request Special Function 44 is set to enable HP IB Code Error Special Function 44 3 The following Special Functions are set to the indicated default values 30 MHz 10000 MHz 1 15 2dB 9893K 296 5K Bomo 16 GHz 3 39 Operation HP 8970B Table 3 6 Response to a Clear Message or Pressing PRESET 1 of 2 ree Noise Figure Measurement System Internal IF Special Function 19 SSB2 IF SSB3 IF DBS IF Plotter Functions Special Function 25 Noise Pen Number Gain Pen Number Plot Title 1 2 Loss Compensation Special Function 34 Before DUT Temperature of Losses After DUT Set Sequence Special Function 35 2 1 through 9 Receiving the Clear Message cont d sage and resets the Service Request Condition Spe cial Function 44 such that the Require Service message will be issued on HP IB code errors only Special Function 44 3
437. ut signal is greater than or equal to 16 GHz the K band amplifier must be removed from the output signal path If the K band amplifier is not removed from the signal path the Noise Figure Meter or Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator will not operate properly Taking the K band amplifier out of the signal path involves modifying the auxiliary commands Special Function 42 0 for Special Function 41 3 The following HP IB program code needs to be added to the auxiliary commands 9SV The decimal equivalent of each ASCII character 9SV is entered into the Noise Figure Meter The decimal equivalents of the ASCII characters are as follows 9 57 S 83 and V 86 Modifying the auxiliary commands is described in the Entering Data section of the Programming the System LO Detailed Operating Instruction After the K band amplifier is removed the local oscillator must be able to supply a leveled 8 dBm over the oscillator s complete bandwidth If the local oscillator can t supply the leveled 8 dBm another local oscillator will have to be selected Related Controller Capability of the Noise Figure Meter Sections Measurement Modes 1 1 through 1 9 Programming the System LO Special Functions 3 221 Operation HP 8970B RF Attenuation Selection Special Functions 60 61 and 62 Description RF attenuation selection display and hold are available in all measurement modes It
438. utine on the Data Ready status bit Refer to Enabling the Service Request Condition paragraph 3 30 g Continue to loop through steps d e and f A method for determining when the calibration is complete must be programmed into the external controller One method is to compare the frequency that is sent to the LO with the stop frequency programmed into the Noise Figure Meter and terminate the program after the third measurement in which they are equal It is also possible to write an SRQ interrupt routine on the Calibration Complete SRQ Refer to Enabling the Service Request Condition para graph 3 30 HP 8970B Comments contd Operation Calibrate cont d Includes Special Function 39 Calibration data can be collected at the time the calibrate command is executed This feature is useful for comparing calibrations to see how the Noise Figure Meter is performing The controller can command the Noise Figure Meter to send both the gain reference GkB and second stage temperature using the HP IB command H2 H2 will cause the Noise Figure Meter to output the following string FFFFFE 06 SCCCCCE XX STTTTITE YY CRLF Where FFFFF is the calibration frequency STTTTT is the sign followed by the second stage temperature value and SCCCCC is the sign followed by the calibration data of GkB for the point being sent The exponents are shown above as XX and YY Thestring is followed with carriage return and line feed The equations for GkB an
439. utput power Use Special Function 42 to define a new program for other system local oscillators h The user controlled local oscillator must be configured to produce the desired IF 10 to 18000 MHz The user controlled local oscillator is not controlled by the Noise Figure Meter i If a free running non synthesized source is being used as the system local oscillator a Noise Figure Test Set Coarse Tuning Calibration should have been done when the Noise Figure Measurement System Noise Figure Meter Noise Figure Test Set and system local oscillator was put together The coarse tuning is ONLY required when a free running source is the system local oscillator or repairs have been made to the Noise Figure Test Set For more information on a Noise Figure Test Set Coarse Tuning refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction There are many possible measurement procedures However the following general procedure applies to all cases 3 169 Operation HP 8970B Measurement Mode 1 7 conta Special Function 1 7 Procedure NOTE cont d High measurement system noise figure leads to high measurement uncertainty when measuring low gain devices A low noise preampli fier between the device under test and the measurement system can lower system noise figure and therefore reduce the measurement un certainty For more information on determining if a preamplifier is needed and selection of the pre
440. was found These steps are repeated for each frequency point to be fine tuned For a Coarse or Fine Tuning Calibration three attempts will be made at each frequency point to find the noise peak After three attempts error code E19 will be generated The causes that generate an error twenty eight E28 are given below a The YIG filter in the Noise Figure Test Set has not been fine tuned at the current frequency and coarse tune data is being used The measurement may not be valid b The current frequency of the Noise Figure Test Set YIG filter has been interpo lated from the Fine Tuning Calibration data The measurement may not be valid c The Noise Figure Test Set has been fine tuned but the temperature has drifted more than five degrees centigrade since the last Fine Tuning Calibration The YIG heater loop must be reset and new fine tuning data gathered Use Special Function 36 3 to reset the heater loop and gather the new fine tune data Usually the solution to error twenty eight E28 is to perform a Fine Tuning Calibra tion using Special Function 36 3 Calibrate Measurement Modes 1 0 through 1 9 Sweep 3 197 Wpelauiuil HP sy UB Noise Figure Uncorrected and Noise Figure Description Procedure Exampie Program Codes HPB indications 3 198 and Gain Corrected UNCORRECTED NOISE FIGURE measures the combined noise figure of the device under test and the measurement system including the effec
441. wing steps must be done in the order given a Set the Noise Figure Meter s System Interface Bus address using Special Function 40 4 The default address of the System Interface Bus is eight 8 b Set the address of the Noise Figure Meter using Special Function 40 0 The default address of the Noise Figure Meter is eight 8 c Set the address of the other controller on the System Interface Bus d Decide if the Noise Figure Meter or the other instrument will be the system controller If the other instrument can be enabled or disabled as system controller either instrument can initially be system controller If the other instrument can only be enabled as system controller the other instrument will initially have to be the system controller and Special Function 48 1 Noise Figure Meter is not the system controller on the System Interface Bus will have to be active NOTE Error forty eight E48 is generated if the Noise Figure Meter detects another controller on the System Interface Bus and the Noise Figure Meter has been told it would be the controller HP 8970B Example cont d Program Codes lt gt indications Operation System Interface Bus Control conta Special Functions 45 through 49 e Special Function 48 0 will enable the Noise Figure Meter as system controller Special Function 48 1 will disable the Noise Figure Meter as system controller Use the appropriate commands to enable or disable the other c
442. with an HP IB cable b Special Function 48 0 active Noise Figure Meter is controller on System Interface Bus Special Function 48 0 is the default setting after using Special Function 0 9 c Special Function 46 0 active Enable local oscillator on System Interface Bus Special Function 46 0 is the default setting after using Special Function 0 9 d The address of the system LO must match the system LO address thatis stored in the Noise Figure Meter Use Special Function 40 1 to display and change this address if necessary The default address is 19 after using Special Function 0 9 e The correct system local oscillator program must be active if the Noise Figure Meter is going to control the system local oscillator The system local oscillator pro grams are listed below HP 8350B Sweep Oscillator Special Function 41 0 HP 8671B 8672A Synthesized Signal Generators Special Function 41 2 HP 8673B C Synthesized Signal Generator Special Function 41 3 HP 8340B 8341B Sweep Oscillator Special Function 41 4 custom local oscillator Special Function 41 5 The custom local oscillator program will support local oscillators that may require a maximum of twenty two characters for the frequency prefix and suffix and or the output power prefix and suffix The prefix and suffix define the command sequence that will set the frequency or output power Use Special Function 42 to define a new program for other system local oscillators
443. working table can be entered into the Noise Figure Meter Each table can have up to 35 entries The Noise Figure Meter uses this data to correct for ENR versus frequency varia tions For measurements made between calibra tion points ENR data is interpolated When the instrument is turned off the ENR tables are stored in nonvolatile memory X and Y Axis outputs on the rear panel allow for noise figure and gain versus frequency to be dis played on a storage or nonstorage oscilloscope or output to a recorder On an oscilloscope gain can be displayed at a lower intensity than noise figure to distinguish between the two traces The Z Axis 1 2 HP 8970B output blanks an oscilloscope or lifts a recorder pen A storage oscilloscope can also be used but the differences in trace intensity are obscured Most functions can be remotely programmed via the Hewlett Packard Interface Bus HP IB and all measurement data is available to the HP IB The Noise Figure Meter has a second bus the System Interface Bus SIB The System Interface Bus is a private bus used by the Noise Figure Meter to control certain instruments in the Noise Figure Measurement System Instruments con trolled by the SIB are the Noise Figure Test Set the System Local Oscillator and a plotter 1 8 Noise Figure Measurement System The Noise Figure Measurement System extends the frequency range of the Noise Figure Meter from 1600 MHz to 18000 MHz The Noise Figure
444. y in the corresponding Special Function code and then press the SPECIAL FUNCTION key Specia Function Program Code Description code a gt Normal Talker and 4 0 None Listener Mode tinuous Memory Special Function 0 0 Conditions Clear Conditions Spectal Function Preset and HP IB 0 9 Conditions se ts amp w Can he Stored and Recalled Function Key Stored in Con Refer to Special 4 1 ascot st ass E See ees Function 46 0 Talk Only Mode 4 2 None N Y N NC NC Off 1 Table categories are explained in the Special Function Detailed Operation Instruction To select the Talk Only Mode LOCAL poo Yaa cone am Function w keystrokes HOD e D HP IB 2 Cannot be selected via HP IB program codes When Special Function 4 2 is active the HP IB TALK annunciator lights In the Talk Only Mode the instrument continuously outputs data to a recording device that is in the Listen Only Mode The data output format and content is controlled by Special Function 43 Refer to the HP IB portion of this section for additional information on this Special Function Since the Noise Figure Meter has a second bus System Interface Bus to control the system LO the Noise Figure Test Set and plotter Special Function 4 1 is no longer used Refer to Special Functions 45 46 and 47 3 71 Operation HP 8970B Controller Capability of the Noise Figure Meter conta Special Function 4
445. y parameters including the fixed frequency for the system LO Spe cial Function 3 1 d Calibrate in Mode 1 2 this is only required for a CORRECTED NOISE FIGURE AND GAIN measurement External filtering is required during both the calibration and the measurement If a preamplifier will be used during the measurement the preamplifier must be used during the calibration e Insert DUT and measure NOTE The following example assumes that the Noise Figure Meter is the controller on the System Interface Bus For information on using an external controller refer to the Comments section at the end of this instruction To make a swept CORRECTED NOISE FIGURE AND GAIN measurement of a wide band amplifier in the 3 5 to 4 5 GHz range using 20 MHz steps and a fixed system LO of 5 GHz a Press PRESET or send HP IB code PR to establish initial conditions b Press 2 1 SPECIAL FUNCTION or send HP IB code Bi to select a lower side band measurement 3 141 Operation HF 8Y UB Measurement Mode 1 2 conta Special Function 1 2 Example NOTE cont d Measurement Mode 1 2 must be activated prior to entering the frequency parameters to avoid error E35 entered value is out of range c Press 1 2 SPECIAL FUNCTION or send HP IB code E2 to activate Mode 1 2 Note that error E33 IF will be out of range is displayed This error is cleared when the correct frequency parameters are entered in step d d Set the frequency parameters
446. ystem Interface Bus Special Function 48 1 OFF will be displayed Then Fr will appear in the INSERTION GAIN display and CAL will appear in the NOISE FIGURE display for approximately five seconds while the Noise Figure Meter performs a frequency calibration 2 Press PRESET After Fr disappears from the INSERTION GAIN display and CAL disappears from the NOISE FIGURE display verify the following conditions NOTE If error code E44 is displayed press 45 0 SPECIAL FUNCTION Since Measurement Mode 1 0 default after PRESET doesn t require the Noise Figure Test Set Special Function 45 0 disables Noise Figure Test Set commands in Measurement Mode 1 0 Left display shows 30 MHz INSERTION GAIN display is blank NOISE FIGURE display shows FdB UNCORRECTED NOISE FIGURE annunciator is on fa op 3 15 Operation HP 8970B OPERATOR S CHECKS Basic Functional Checks cont d Procedure cont d 3 4 5 Enter the Excess Noise Ratio ENR data for the noise source being used For more information refer to the ENR Table Entry Detailed Operating Instruction Con nect the noise source between the Noise Figure Meter s SOURCE and INPUT see Figure 3 9 Verify the NOISE FIGURE display shows approximately 5 dB Connect the display to the X Y and Z AXIS connectors on the rear panel of the Noise Figure Meter Use the X AXIS for the horizontal input and the Y AXIS for th
447. ystem controller Special Function 48 1 Finally the Noise Figure Meter has the capability of allowing an external computer on the Hewlett Packard Interface Bus to gain control of an instrument on the System Interface Bus The mode used is called Pass Through Mode Pass Through Mode is described in the Example section of this instruction HP 8970B Description cont d Operation System Interface Bus Control conta Special Functions 45 through 49 The following descriptions will give a better understanding of Special Functions 45 through 49 a Special Function 45 0 enables the commands for the Noise Figure Test Set to be sent on the SIB in Measurement Modes 1 5 through 1 9 b Special Function 45 1 enables the commands for the Noise Figure Test Set to be sent on the SIB in Measurement Modes 1 0 through 1 9 When Special Function 45 1 is active the Noise Figure Test Set is set to bypass mode SSB1 in Measurement Modes 1 0 through 1 4 This means that the measurement signal is passed straight through the Noise Figure Test Set with only a 3 dB loss c Special Function 45 2 disables the commands for the Noise Figure Test Set d Special Function 46 0 enables the commands for the System Local Oscillator to be sent on the SIB in Measurement Modes 1 1 through 1 9 e Special Function 46 1 disables the commands for the System Local Oscillator in Measurement Modes 1 1 through 1 9 f Special Function 47 0 conveys to the Noise
448. ystem is initially put together and the system loca oscillatoris a sweeper or ifrepairs are done to the Noise Figure Test Set Also if a fine tune calibration is being performed loss after the Noise Source can cause this error Some calibration setups with loss between the Noise Source and the Noise Figure Test Set may require the use of a preamplifier It is possible to do a fine tuning calibration with the Noise Source connected directly to the Noise Figure Test Set s INPUT if a preamplifier is not available The Noise Source should have at least 12 dB ENR Excess Noise Ratio for a fine tuning calibration without a preamplifier For additional information refer to the Noise Figure Test Set YIG Filter Calibration Detailed Operating Instruction Error code E21 is generated if the current frequency is out of the calibrated measurement range In Measurement Modes 1 5 through 1 9 the current frequency may be in the calibrated measurement range but the frequency may not be an actual calibrated frequency Since corrected measurements are very susceptible to small changes in the system noise figure it is not advisable to expect good data between calibration points especially if the points are separated by many megahertz Also because of discontinuities in the band crossings of the Noise Figure Test Set the Noise Figure Meter cannot interpolate across the Noise Figure Test Set s band crossings For instance when one calibration point is in SSB
449. ystrokes program codes For HP IB codes refer to Procedure above When Special Function 50 0 is selected the Noise Figure Meter automatically sequences through all eight lines showing the status of each line for approximately one second in the left display When Special Functions 50 1 through 50 8 are selected the status of the corresponding line is displayed in the left display until another function is selected Under the left display are reference characters N 1 2 3 and 4 N refers to the line number and 1 2 3 and 4 refer to digit positions in the display To read the special function catalog information via HP IB use Special Functions 50 1 through 50 8 and read one line ata time The HP IB output format must be set to output all three displays HP IB code H1 or 43 1SP Special Functions HP 8970B Description Operation Special Functions General Information Special Functions extend user control of the instrument beyond that normally available from dedicated front panel keys They are accessed via keyboard entry of the appropriate numeric code terminated by the SPECIAL FUNC TION key The codes consist of a prefix decimal and suffix Special Functions are grouped by their prefixes into five categories as follows Prefix 0 This initializes selected Special Functions Refer to Table 3 14 Special Function Summary for a complete listing of initialized Special Function conditions Prefixes 1 to 49 Th
450. z 494 MHz 506 MHz 1000 MHz 994 MHz 1006 MHz 1300 MHz 1294 MHz 1306 MHz 1600 MHz 1594 MHz 1606 MHz 4 6 INPUT SWR PERFORMANCE TEST 20 dB Input Gain Setting Frequency MHz 11 73 dB MHz 11 73 dB MHz 11 73 dB 10 dB Input Gain Setting Frequency MHz 11 73 dB MHz 11 73 dB MHz 11 73 dB 0 dB Input Gain Setting Frequency MHz 11 73 dB MHz 11 73 dB MHz 11 73 dB 4 7 NOISE FIGURE RANGE AND ACCURACY PERFORMANCE TEST z Difference Step 9 Step 10 ee Se 0 00053 0 00054 Step 12 Step 13 Step 9 Step 10 0 00589 0 00603 Step 15 Step 16 Step 9 Step 10 Step 18 Step 19 0 04922 0 05037 Step 9 Step 10 Step 9 Step 10 0 69706 0 71330 Step 24 Step 25 Step 18 Step 19 Step 27 Step 287 0 69706 0 71330 4 25 Performance Tests HP 8970B Table 4 2 Performance Test Record 2 of 3 GAIN MEASUREMENT UNCERTAINTY PERFORMANCE TEST Power Meter Reading Step 35 dB Step 38 dB Noise Figure Meter Reading Step 36 dB Step 39 dB Step 45 Step 50 Step 46 Step 51 dB dB Step 48 Step 50 Step 49 Step 51 dB dB 4 9 INSTRUMENT NOISE FIGURE PERFORMANCE TEST 0 15 dB 0 15 dB 0 15 dB 0 15 dB Frequency 10 MHz 7 03 FdB 110 MHz 7 33 FdB 210 MHz 7 63 FdB 310 MHz 7 93 FdB 410 MHz 8 23 FdB 510 MHz 8 53 FdB 610 MHz 8 83 FdB 710 MHz 9 13 F

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