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FireFox User Manual

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1. indicator 1 4 4 Setting the Frequency Figure 1 1 shows the front panel LCD and keys used to change the output frequency of the FireFox Signal Generator The LCD shows either the frequency setting mode or the menu mode The frequency setting mode is the default mode after power up Press the menu key until the unit shows the frequency setting mode if the unit is in any of the sub menus The left and right keys now control the cursor which can be moved onto any of the frequency triplets or onto the RF output power setting The cursor will wrap around the display automatically 6 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs Use the up and down keys to change the frequency triplet You may also press and hold the up or down keys to automatically scan through the frequency range The speed of the scan will increase after a short time intervall When scanning the frequency using the down key the display will show 0Hz after some time if the selected frequency triplet has been reduced to 0Hz Release the down key then press and hold the down key again to start scanning the frequency triplet below the one originally selected The frequency scanning in this mode will then start at 999 Hz As an example set the frequency to 10 0MHz Now place the cursor onto the O digit of the 10MHz triplet the single MHz digit Press and hold the down key and the frequency will scan through 9 8 7 0 MHz The display will no
2. DC to 390MHz Frequencies above 390MHz are generated by a very low phase noise PLL controlled VCO phase locked to the internal DDS 3 6 2 How can spur performance be increased even further An LC type output filter can be used to reduce out of band spurs These filters can be designed with public domain software see for example Elsie an easy to use filter designer available at www tonnesoftware com or these can be purchased off the shelf Mini Circuits www minicircuits com offers such filters as small inexpensive ceramic components in their LFCN and HFCN series filters 3 6 3 Does the FireFox need calibration The FireFox system never needs frequency calibration it is constantly being calibrated by the GPS timing signal The FireFox RF output amplitude has been calibrated at the factory and it is recommended that the unit is returned to Jackson Labs once a year for amplitude calibration The user may also self calibrate the FireFox units using an Agilent power meter see the hardware FAQ 3 6 4 There is a Frequency Estimate display in the menus What is this number The FireFox system constantly measures the internal OCXO offset to the GPS 1PPS signal This measurement is done in 10ns steps 100MHz sampling The firmware then adjusts the OCXO steering voltage Electronic Frequency Control EFC to compensate for any drift between the OCXO and UTC The timing differences between the OCXO and the 1PPS signal are stored in memory on
3. Jackson Labs does not warrant that the operation for the software firmware or hardware shall be uninterrupted or error free even if the product is operated within its specifications For warranty service this product must be returned to Jackson Labs or a service facility designated by Jackson Labs Customer shall prepay shipping charges and shall pay all duties and taxes for products returned to Jackson Labs for warranty service Except for products returned to Customer from another country Jackson Labs shall pay for return of products to Customer If Jackson Labs is unable within a reasonable time to repair or replace any product to condition as warranted the Customer shall be entitled to a refund of the purchase price upon return of the product to Jackson Labs 1 2 2 Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Customer Customer supplied software or interfacing unauthorized modification or misuse opening of the instruments enclosure or removal of the instruments panels operation outside of the environmental or electrical specifications for the product or improper site preparation and maintenance JACKSON LABS SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE No license express or implied by estoppel or otherwise to any intellectual property rights is granted by this document Jackson Labs product
4. Labs 2 5 3 1 SOURce POWer LEVel IMME diate AMPLitude lt numeric value gt This command sets the actual magnitude of the output signal in SWEEP and CW mode The unit is defined in dBm On RST the power magnitude is set to the minimum of 40dBm 2 5 4 Phase Subsystem The FireFox DDS provides a 14 bit internal phase control The phase can be changed in relation to the back panel GPSDO 10MHz reference output The phase can be controlled over the a complete 360 degrees cycle 2 5 4 1 SOURce PHASe ADJUST lt numeric value gt lt unit gt This command controls the phase offset value relative to the GPS Disciplined OCXO GPSDO reference The phase value can be expressed in radians no suffix or in degrees suffix DEG and should be defined in the interval PI PI radians or 180 180 Degrees On RST this value is set to 0 2 5 5 Output Subsystem This command controls the RF output connector of the FireFox Signal Generator 2 5 5 1 OUTPut STATe lt ON OFF gt This command controls the RF output of the Firefox At RST the output state is OFF The output state has to be ON for CW and SWEEP to generate a signal on the RF port 2 5 6 Initiate Subsystem The Initiate Subsystem controls the sweep functionality of the FireFox Signal Generator 2 5 6 1 INITiate The supported options for this command are e CONTinuous ALL lt ON OFF gt e IMMEdiate The INITiate subsystem is used to control the initia
5. gt DDS gt MIXER menu Turning off the mixer may help prevent some spurs and may be usefull when debugging IF and AGC circuitry etc 1 4 7 3 FRACT ON OFF The menu item SETUP gt DDS gt FRACT ON OFF determines the mode of the FireFox Signal Generator Fractional N DDS to be used or to be disabled This setting determines the FireFox Signal Generator resolution and also affects the output phase noise and frequency drift Select FRACT ON to set the DDS to 48 bit Frequency mode or FRACT OFF to turn off the Fractional N mode and set the unit to 32 bit Frequency mode See Section 3 6 6 for an in depth discussion of the Fractional N operating mode 1 4 7 4 Noise Spur Optimization The menu item SETUP gt DDS gt NOISE SPUR OPT allows the internal FireFox PLLs to be setup for either best noise performance Spur optimization turned to OFF or best spur performance Spur optimization turned to ON This setting will affect the PLL charge currents of the internal PLLs and place these either in the best operating mode for Phase Noise performance or for least Spur performance Set this item to OFF for typical operations that require low phase noise signals 1 4 8 Setting up the Output The following settings affect the FireFox maximum frequency that can be generated as well as the analog front panel RF Output power 1 4 8 1 Frequency Limit In the SETUP gt OUTPUT gt FREQ LIMIT menu the user may limit the maximum possible frequency t
6. 9 You can verify proper operation of the FireFox RF output using the power meter as it is connected for calibration The FireFox output power from 30dBm to 5dBm should be within 1dBm and are typically within 0 2dBm after calibration when measured with the setup describe above and if the power meter is set to the proper frequency using its Frequency button 2006 Jackson Labs
7. a Factory Reset is only initiated if the unit stops responding correctly to user commands 1 4 14 2 GPS TRAIM Filter The GPS receiver can operate with an internal TRAIM Time Receiver Autonomous Integrity Monitoring algorithm to ensure that data from bad Satellites will not corrupt the FireFox Signal Generator Time Base accuracy The receiver requires at least 4 Satellites to be received and to be in good status when entering the SETUP gt GPS gt GPS TRAIM FILTER menu and selecting GPS 1PPS FILTER ON Any Satellite solutions with less than 4 Sats being received or with any one Sat exceeding 300ns deviation from the others will be considered stale by the GPS firmware when this option is set to ON Jackson Labs recommends maintaining this setting in the OFF position when using the default FireFox Signal Generator OCXO and only setting this option to ON when using the ultra high stability double oven OCXO option with a GPS Antenna that has a clear view of the sky 14 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 1 4 14 3 Controlling the M12 GPS Receiver using a PC You may use Motorola s WinOncorel2 Windows tm program to check the Motorola M12 GPS Timing receiver status and to modify advanced settings of the GPS receiver such as Satellite Mask Angles etc Please see the GPS FAQs on the Jackson Labs website www jackson labs com for pointers where to download the WinOncore12 utility Follow these steps in or
8. about the requirements for executing a self calibration of the RF amplitude levels 1 4 16 Entering SCPI Remote Control Mode Beginning with Firmware Revision 3 0 and later the FireFox Signal Generator may be controlled via its rear panel RS 232 connector using the SCPI 99 industry standard communication protocol See Chapter 2 for a list of supported SCPI commands The user can manually enter the SCPI remote control mode by pressing SETUP gt COMMUNICATION gt SCPI MODE in the menu The user may select the SCPI RS 232 communication BAUD rate via the SETUP gt COMMUNICATION gt SERIAL SPEED menu 2006 Jackson Labs 15 FireFox Synthesizer User Manual 1 5 FireFox Desktop Typical Specifications 1 5 1 Specification Summary ksony Jac son f Item Description Specification Frequency Range DC 1640MHz Resolution 10 micro Hertz Accuracy measured over 30 minutes lt 5E 010 Settling time lt lt 10ms Frequency Sweeping Start and Stop Frequency Frequency update rate Sweep Mode Sweep Time Repetition RF output power Arbitrary from OHz to 1640MHz 500 updates per Second Linear and Logarithmic 0 1 1000s F1 gt F2 or F1 gt F2 F1 Leveled between 40dBm and 10dBm better than 1dBm level accuracy Time Base Stability See Figure 1 2 for typi cal Allan Deviation Aging Fully corrected by GPS Warm up time from cold boot 20 Degree Celsius lt 1 hour Lock time with GPS reception lt 5 hou
9. being received and used for the timing solution The STAT item is a status indicator having the following meaning BG Bad Geometry This indicates that the satellite positions are not differentiated enough to be usable in Auto Survey mode AQ Acquiring This indicates that the unit is looking for satellites to track UL Unlocked The unit is receiving satellite timing information but has not finished locking the OCXO to UTC yet O 2006 Jackson Labs 49 FireFox Synthesizer User Manual J a ck S on Labs AS 3D 2D Position fixes The unit is receiving 3D or 2D position fixes when in Auto Survey mode Ten thousand readings are required to finish Auto Survey mode OK Position hold mode with locked OCXO The unit has locked the OCXO to UTC and sufficient satellites are being received to maintain lock 3 6 Performance FAQs The following FAQs describe the performance of the FireFox Signal Generators and it s features 3 6 1 How does the FireFox Synthesizer offer such wide bandwidth The FireFox synthesizers internal circuitry divides the output bandwidth into four bands with each band optimized to reduce noise spurs and to offer the best linearity possible The frequency bands are DC 0 00001Hz to 30MHz 30MHz to 390MHz 390MHz to 770MHz and 770MHz to 1 64GHz These bands are switched seamlessly in the background A Direct Digital Synthesizer DDS with a 10 bit DAC and 1GHz sample rate generates the first two bands
10. calibrated output power into a resistive 50 Ohm load connected directly at the RF output connector on the front of the unit with typically better than 0 2dBm accuracy and 0 02dBm resolution Move the cursor onto the RF amplitude digits in the frequency setting mode Press the up or down keys to change the output power The unit also has a power limit menu similar to the frequency limit menu explained in paragraph 1 4 4 Please check the power limit in the SETUP gt OUTPUT gt POWER LIMIT menu if you are unable to select a desired power level up to 100 or 10dBm 2006 Jackson Labs 7 FireFox Synthesizer User Manual J a ck S on Labs 1 4 6 Using the CMOS and LVDS outputs The FireFox unit is unique in that it can produce both analog sine wave outputs and digital outputs simultaneously Four front panel digital outputs are available All four outputs on the front panel are driven in parallel within their respective output frequency ranges as indicated by the VALID LEDs Please note that the LVDS outputs have an under range from 2 10MHz The outputs are driven in this under range but are not guaranteed to be jitter free The CMOS output is usable from 0Hz to 350MHz with an over range up to 390MHz in which the output is driven and usable but not guaranteed to be jitter free 1 4 6 1 Connecting a cable to the LVDS Outputs Two differential complementary LVDS signals are available on SMA connectors on the front panel of the FireFox u
11. can generate frequencies from 0Hz to 350MHz with an overrange of up to 390MHz This output is typically used to clock digital circuits such as microprocessors FPGAs DDR SDRAM memories and ASICs The output is typically fed into a 50 Ohm transmission line or coax cable and left unterminated at the receiver Using a 50 Ohm termination resistor at the receiver will cause a ca 50 reduced voltage output swing End termination is not recommended but will not harm the output RF OUTPUT 500hms 2MHz to 1640MHz range 40dbm to 10dbm typ Can be used as the local oscillator for any RF type application Maximum power typically ranges from 10dbm to 15dbm depending on the frequency Has leveled output capability with output power selected via keypad This output can be used as the local oscillator source for the built in generic Mixer use 10dbm output max to avoid mixer damage The RF output requires 50 Ohm end termination LVDS OUTPUT 500hms DC coupled 10MHz to 1640MHz 300mVpp with a 2MHz to 10MHz underrange 22 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs a standard positive DC biased differential LVDS output is available on two SMA connectors These signals are typically used to drive ultra high speed digital signals into FPGA s ASICs backplanes or memories For LVDS compatible signals two 1000hm differentially terminated transmission lines or coax cables are typically connected to these output
12. receiver locks into its final position hold mode within 2 5 5 hours after which it will receive the position corrected timing information from the GPS receivers The Auto Survey mode settings are saved in NV 48 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs memory and the mode will not have to be invoked again unless the unit is turned off for longer than 2 days typically or the units antenna is moved more than 30 feet 3 5 6 What is the T RAIM mode in the GPS receiver The FireFox GPS receiver includes an optional Motorola Time RAIM Time Receiver Autonomous Integrity Monitoring algorithm for checking the timing solution integrity This mode is invoked via the front panel menu and allows the GPS receiver to check the quality of a satellite receivers signal It will mask off signals from Satellites that indicate any fault conditions or if the particular GPS signal is outside certain limits compared to three or more other satellite signals This Algorithm prevents faulty satellites or adverse atmospheric conditions from affecting the precision of the FireFox synthesizer T RAIM is unique to the FireFox system and its Motorola GPS timing receiver 3 5 7 Why did you not use a cheap standard GPS receiver Competitive products use standard GPS receivers to save cost or because they were designed prior to GPS timing receivers becoming available These receivers are optimized for navigational purposes and d
13. 006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs Figure 1 3 shows the typical Allan Deviation when using the optional ultra high stability double oven OCXO Note the significant stability improvement for time periods above 1s measurement intervals when using the double oven OCXO option as compared to the standard OCXO Allan Deviation oy 7T 10 10 EN 10 11 nie UR pue NY QUE AL 1 le al 10 12 10 13 10 2 10 1 100 10 102 103 104 105 Averaging Time t seconds Ch A 5 0 MHz 3 3 Vpp Ch B 5 0 MHz 1 8 Vpp Instantaneous Phase B A Single DDS Figure 1 3 Typical Allan Deviation of 5MHz front panel output with double oven Ultra High Stability OCXO option It can be clearly seen from Figure 1 3 that the FireFox Signal Generator equipped with the ultra high stability OCXO option achieves better than 1E 12 timing stability in less than 10 hour measurement intervals when locked to GPS The rear panel 1PPS output of the FireFox Signal Generator is driven by the Motorola M12 GPS timing receiver The 1PPS BNC output is only active when the unit is locked to at least one satellite See Figure 1 4 for a typical Frequency Stability measurement of the FireFox 1PPS output when compared to an ultra high stability reference It can be seen that the FireFox 1PPS output can achieve about 1E 12 timing stability in less than 24 hour measurement intervals when locked to GPS The FireFox Signal Generator already achieves this excellent stab
14. 06 Jackson Labs 51 FireFox Synthesizer User Manual Ja ck S on Labs 10 0MHz 4294967296 1GHz 2 32 The advantage of integer mode is thus that this particular tuning word generates a cycle accurate phase drift free 10MHZ signal without any cycle slipping or residual The phase angle to the internal 10MHz OCXO is fixed and remains drift free The disadvantage of this mode is its granularity which is limited by the 32bit tuning word The frequency granularity with fractional mode turned off and an output frequency ranging from 2MHz to 390MHz is thus exactly 0 23283064365386962890625Hz Keep in mind that the absolute accuracy of the output signal is limited by the accuracy of the 10MHz reference signal from the OCXO To improve the frequency granularity of the output signal a fractional N mode can be enabled that increases the frequency resolution by an additional 1 6bits The disadvantage of this mode is that it is not mathematically deterministic there is a frequency uncertainty of about 1 2LSB that prevents this mode from being cycle accurate By increasing the DDS resolution the DDS residual is made very small about 1GHz 248 at a 10MHz output frequency The frequency resolution with fractional N mode turned on is thus 3 55 Hz for an output ranging from 2MHz to 390MHz This DDS resolution is typically less than the systems minimum resolution of 10uHz The system attempts to match the user selected 10 Hz step setting to the c
15. 2 5 6 Initiate Subsystem BT 2 5 6 1 INITIate g e s 4 4 ee M a ga gs NE 4 amp h au an 4 497 2 5 7 Measure Subsystem ee dea AP o E a SO 2 5 7 1 MEASure TEMPerature Boe 44 ee a a ds amp Bd aoe 3 8 2 5 8 System Subsystem Oa oe age amp oes wae e 4 ADO 2 5 8 1 SYSTem COMMunicate SERial be a he JS ede toe oe 438 SYSTem COMMunicate SERial BAUD lt numeric_value gt 38 SYSTem COMMunicate SERial ECHO ON OFF 38 2 5 9 Miscellaneous proprietary commands 39 2 591 HELP ass dae eS a Re Re AE ae 99 259 2 SOURCE 2 Se Gack Goa ek de L amp oe DO 2 6 SCPI Command Examples poa Gen dk amp ADO 2 6 1 Setting the FireFox into Continuous Wave Mode OD Ss pm E es Per E ROO 2 6 2 Configuration and Settings Query 39 3 FAQS Ghee eed eh Ee eee EET ananas ga AMA 3 1 OVERVIEW 40 uma mm ae Be ea Re ae Ae amp de ee oe 41 3 2 General FAQs _ 1 3 2 1 How can the FireFox Synthesizers offer such high performance for such a low price 41 3 2 2 How did you decide what features to include in the FireFox synthesizers 41 3 2 3 How long does the FireFox system take to warm up 4 3 2 4 Why is there no power switch on the FireFox 42 3 3 Application Usage FAQs 42 3 3 1 What is the difference between the FireFox Desktop u
16. F output follow these steps after letting the equipment warm up for at least 30 minutes 1 Connect an Agilent E4418B power meter via its RS 232 serial port to the FireFox System RS 232 port using a female to female DB 9 NULL MODEM cable 2 Use an Agilent 8482A power sensor and calibrate it using the power meters CAL output Make sure to manually program the sensor correction factors into the E4418B power meter see the power meters and sensors user manuals 3 Connect the 8482A power sensor to the FireFox RF analog output through a short BNC to N type adapter Do not use a cable to connect the sensor to the FireFox the cable would reduce the calibration accuracy 4 Start the calibration program in the MENU SETUP CALIBRATION SETUP menu You should immediately see the power meter display show varying readings and frequencies in its LCD display the display should update once every second or so The FireFox LCD display will also show varying power frequency and DAC readings 5 After several hours the unit will display a power cycle now message after the calibration has finished Make sure to power cycle the unit when prompted to do so and do not interrupt the power calibration cycle During step 4 the unit will auto calibrate itself this process will take several hours to complete The calibration parameters are stored in its internal Flash memory after the calibration process completes 3 5 GPS R
17. NALog 2008 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 2 5 2 8 SOURce SWEep SPACing lt LINear LOGarithmic gt This command controls the pace of the sweep functionality The logarithmic spacing is only available on Software Controlled sweeping mode Upon RST this value is set to LINear 2 5 2 9 SOURce SWEep DIRection lt UP DOWN UPDOWN gt This command controls the direction of the sweep If the direction is UP DOWN the sweep frequency will vary from the selected STARt STOP frequency to the STOP START frequency The direction UPDOWN is a proprietary setting that allows the sweep to go up from the STARt frequency to the STOP frequency and decrease in the opposite direction In this case the total duration of the sweep is doubled Upon RST the direction is set to UP 2 5 2 10 SOURce SWEep COUNt lt numeric value gt This command determines the number of sweeps which are enabled by a single trigger event This command has no effect if the Continuous trigger is used Upon RST this value is set to 1 2 5 2 11 Software Controlled Sweep configuration example Complete command syntax style SOURce FREQuency MODE SWEep SOURce FREQuency STARt 100 Mhz SOURce FREQuency STOP 1 Ghz SOURce POWer 2 SOURce SWEep MODE SW SOURce SWEep SPACing LOGarithmic SOURce S WEep TIME 30 SOURce SWEep GENeration ANALog OUTPut ON INTTiate IMME Alternative abbreviated style resulting in the same out
18. OURce FREQuency CW 31 SOURce FREQuency MODE 31 SOURce FREQuency CENTer lt numeric value gt 31 SOURce FREQuency SPAN lt numeric value gt 32 SOURce FREQuency STARt lt numeric value gt 32 SOURce FREQuency STOP lt numeric value gt 32 2 5 2 Sweep subsystem 2 5 2 1 SOURce SWEep a a 2 5 2 2 SOURce SWEep MODE lt HW sw gt 2 5 2 3 SOURce SWEep DWELI lt numeric value gt 2 5 2 4 SOURce SWEep POINTs lt numeric value gt 2 5 2 5 SOURce SWEep TIME lt numeric value AUTO gt O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 2 5 2 6 SOURce SWEep STEP Lu 34 2 5 2 7 SOURCce SWEep GENeration lt ANALog STEPped gt 34 2 5 2 8 SOURce SWEep SPACing lt LINear LOGarithmic gt 35 2 5 2 9 SOURce SWEep DIRection lt UP DOWN UPDOWN gt 35 2 5 2 10 SOURce SWEep COUNt lt numeric value gt oh a a soD 2 5 2 11Software Controlled Sweep configuration example 35 2 5 2 12Hardware Controlled Sweep configuration example 36 2 5 3 Power Subsystem 36 2 5 3 1 SOURce POWer LEVel WME ate AMPLitude lt numeric value gt 37 2 5 4 Phase Subsystem E sise 4 OT 2 5 4 1 SOURce PHASe ADJUST lt numeric_ value gt lt unit gt oe Moe amp SOL 2 5 5 Output Subsystem e Ao E ace e ow a 4 4 497 2 5 5 1 OUTPut STATe lt ON OFF gt bad e pog amp amp M 97
19. a from this calibration table needs to be entered into and enabled in the Agilent power meter by hand it is then stored inside the power meter Please follow the Agilent user manual to enter and enable the sensor cal table data into the power meter The power meter is not accurate without properly typing in and enabling the calibration table in the power meter 4 2 2 Using alternate Power Sensors Power Meters Other Agilent power sensors may be used if they have at least a 30dBm to 10dBm power sensing range and 100K Hz to 1 7GHz frequency range 2006 Jackson Labs 53 FireFox Synthesizer User Manual Jackson a bs E4418B specific control codes are sent to the Agilent power meter via the RS 232 serial port in SCPI format so power meters that are not E4418B RS 232 SCPI compatible will not function with the FireFox auto calibration procedure 4 2 3 Calibrating the Power Sensor The Agilent power meter has a Power Reference output that is used to calibrate the power sensor at 50MHz Plug in the 8482A power sensor into the Power Ref output of the power meter see Figure 4 1 Press the ZERO CAL button on the front of the power meter and follow the instructions in the LCD display to zero and calibrate the sensor Figure 4 1 Calibrating the Agilent power sensor The power meter is now properly prepared Agilent recommends to recalibrate the sensor every 24 hours or if the ambient temperature changes 4 3 Calibration Setup Prio
20. adio tuned to 100MHz The received signal will now be audible by the radio Typical signal levels at the mixer inputs are 20dBm to 5 dBm for the RF input and Odbm for the LO input Care must be exercised to avoid driving the Mixer RF and LO inputs above 10dbm Driving the inputs above this level could damage the mixer The mixer can be disabled in the menu settings to reduce potential interference 3 4 4 How can calibrate the FireFox Signal Generator The FireFox Signal Generator never needs frequency calibration it automatically and continuously calibrates itself using the GPS signals The RF analog signal output level is calibrated at the factory and it is recommended that the user calibrates the unit annually to maintain output amplitude accuracy in absolute power mode when using the dBm indicator in the LCD The unit has sophisticated calibration software built in and it can automatically calibrate itself completely without user interaction You will need the following equipment to calibrate the FireFox 1 Agilent E4418B or E4419B power meter with DB 9 RS 232 serial port option 2 Agilent 8482A power sensor or any other Agilent power sensor with 30 dBm to 10 dBm and 2MHz to 1 64GHz range 3 Short BNC to N type adapter to connect the power sensor to the FireFox BNC RF output connector 46 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 4 RS 232 DB 9 Null Modem cable To calibrate the FireFox R
21. all and erase setups enter the Memory menu by pressing MEMORY gt RECALL SAVE ERASE Once inside the SAVE or RECALL menu items press the UP or DOWN key to select a memory position to save to or recall from Positions 0 to 9 are selectable ce 57 An empty memory position is indicated by a sign an occupied position is indicated by a sign Save a memory setup by pressing the ENTER key in the SAVE menu You may exit the save menu by pressing the EXIT MENU key Recall a memory location by pressing the ENTER key in the RECALL menu You can exit without recalling by pressing the EXIT MENU key The user may erase only the entire memory This is useful if all memory locations have been filled up and the older data is no longer useful Erase all memory positions by pressing ENTER in the ERASE menu Exit the erase menu without erasing any data by pressing the EXIT MENU button All FireFox settings such as Maximum Frequency Power settings the Frequency Power Unit output power and other settings are saved in these memory locations Please note that GPS relevant data such as the GPS position in Position Hold mode the GPS GMT time offset etc are not maintained in these memory locations but rather inside the GPS itself 1 4 13 Using the GPS and OCXO Reference Outputs 1 4 13 1 GPS Receiver 1PPS Output The FireFox Signal Generator provides a highly stable IPPS CMOS 3 3V compatible output pulse on its rear panel IPPS BNC con
22. ameters when in sweep mode In sweep mode the unit may generate a frequency sweep between any two arbitrary frequencies ranging from 0Hz to 1640MHz Two commands exist to control frequency sweeping SOURCE FREQUENCY and SOURCE SWEEP 2 5 1 1 SOURce FREQuency The supported options are e CW FIXed lt numeric value gt lt unit gt e MODE lt CW FIXed SWEep gt e CENTer lt numeric value gt lt unit gt e SPAN lt numeric value gt lt unit gt e STARt lt numeric value gt lt unit gt e STOP lt numeric value gt lt unit gt 2 5 1 1 1 SOURce FREQuency CW The Continuous Wave or FIXed node is used to select a single output frequency This node is optional The units supported are Ghz Mhz Khz Hz uHz By default when no units are specified the value is considered to be in Hertz Ifthe output state is turned on as described in section 2 5 5 1 and the frequency mode is CW the frequency output will be changed immediately upon reception of the command This command is an alias of the command FIX ed 2 5 1 1 2 SOURce FREQuency MODE This command changes the FireFox mode Only two modes are supported Sweep or CW The FIXed mode is an alias of the CW mode 2 5 1 1 3 SOURce FREQuency CENTer lt numeric value gt This command sets the Center frequency The change of this value will affect Start and Stop frequency in the following way e Start Center Span 2 e Stop Cen
23. an also be queried or changed through the keypad interface This value is not affected on RST and it is stored in the non volatile EEPROM Please check this setting in the menu if communication to the FireFox Signals Generator is not possible the Baud Rate may have been set and stored at an incorrect value 2 5 8 1 2 SYS Tem COMMunicate SERial ECHO ON OFF This command enables the echo functionality on the RS 232 port This option is convenient when the FireFox is directly controlled via a VT100 like terminal When the ECHO functionality is on the lt backspace gt character is recognized and correctly managed This value is not affected on RST 38 O 2008 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 2 5 9 Miscellaneous proprietary commands In order to facilitate use of the SCPI commands the following proprietary commands have been added 2 5 9 1 HELP This command give a summary of all the SCPI commands available on the FireFox Signal Generator 2 5 9 2 SOURCE This command displays the setting of the entire source subsystem 2 6 SCPI Command Examples The following examples showcase how the SCPI interface commands may be used to operate the FireFox Signal Generator 2 6 1 Setting the FireFox into Continuous Wave Mode Complete command syntax style e SOURce FREQuency CW 123 456 Mhz lt cr gt e OUTPut ON e POWer 0 Alternative abbreviated style e FREQ 123456000 lt cr gt e OUTP l lt cr
24. anual Labs Figure 1 8 FireFox OEM Module System Board Top 1 6 10 Generic Mixer The FireFox synthesizer includes a generic broadband mixer that is accessible via three SMA connectors FireFox OEM module or three BNC connectors FireFox desktop unit The mixer can be disabled via the front panel keypad for power savings and interference reduction The FireFox mixer is completely independent of any other function of the FireFox unit and can be operated independently of other signals on the FireFox synthesizer Typical applications of the FireFox mixer however would use the FireFox analog RF output as the Local Oscillator LO driver of the FireFox mixer The RF input of the mixer could then be connected to an external LNA buffer and band select filter The Intermediate Frequency IF output of the mixer can then be connected to IF demodulators etc Using the FireFox RF output as an LO signal source for the mixer allows frequencies up to 2GHz to be mixed down to the 350MHz bandwidth of the mixer output Care must be exercised to avoid driving the mixer input above 10dbm because this would cause damage to the mixer input The RF output of the FireFox synthesizer is easily capable of generating damaging signal levels above the 10dbm damage level of the Mixer inputs 2006 Jackson Labs 27 FireFox Synthesizer User Manual J a C k S on Labs 28 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs SCPI Remote Cont
25. ce per minute over a 30 minute period The momentary difference is then compared to the difference that was measured 30 minutes ago and a drift is calculated from these two values Thus an 50 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs estimate of the overall time base drift over the last 30 minutes can be established This drift is typically less than 5x10 11 over a thirty minute period when locked to the GPS signal As an example let s assume the Frequency Estimate display indicates 1 6 x10 11 At 100MHz output frequency we can calculate the estimated accuracy of the output signal to be 100MHz 1 6 x10 11 0 0016Hz Thus the absolute frequency error of the output to the UTC atomic reference is estimated to be 1 6mHz and the output frequency is thus estimated as 100 000 000 0016Hz 3 6 5 There is a Resolution number displayed in the menus What is this number This value shows the minimum step resolution that the DDS can generate in the particular frequency band it is operating in The DDS system has 32bit integer accuracy with an additional 16bit fractional component The resolution is applied to three frequency ranges DC 390 390 770 770 1640MHz The effective frequency resolution is thus over 48bits This resolution determines the smallest frequency step size that can be generated by the DDS system and thus determines the residual mathematical error of the system The smallest fractional freq
26. ck diagram of the FireFox synthesizer 20 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs i GPS DISCIPLINED ii FREQUENCY REFERENCE LPF IF OUT i 10MHz l Anas 10 0MHz Deste 0 3MHz 350MHz OUT pee hore Reference PLL Generic ocxo 1Gs s DAC Broadband RF IN bee Mixer 3MHz 2000MHz OUT LO IN 3MHz 2000MHz GPS a E Jo E oo mooo a ANTENNA GES Ting Microcontroller RS 232 Variable x Gain 2MHz 1640MHz Amp 40 10dbm R 400 800MHz PLL 300mVpp cmos CMOS OUT MUX BUFFER 0Hz 350MHz 3 3 5Vpp 10V 5V 33V 5V RS 232 32bit RISC 800MHz LVDS LVDS OUT Controller 1 64GHz PLL BUFFER 10MHz 1640MHz Power Supplies FireFox Synthesizer Block Diagram c 2005 Jackson Labs 110 220V AC Figure 1 5 FireFox Synthesizer Block Diagram 1 6 Detailed Overview The following paragraphs provide an in depth overview of the features applications and capabilities of the FireFox Signal Generators 1 6 1 Applications The FireFox Synthesizer has five outputs to provide signals to applications that require a low noise low jitter accurate and stable frequency signal All outputs are driven in parallel limited to their respective frequency operating ranges as indicated by their VALID LED s which are located adjacent to their respective outputs Any variety of outputs may be used independently of each other A
27. d the GPS will automatically enter the Position Hold mode In Position Hold mode the GPS receiver no longer solves for position and only one satellite is required to accurately determine time The Autosurvey activation is located in the SETUP gt GPS menu section For a better position accuracy it is also recommended to setup the Antenna Cable Delay in the GPS Config menu Caveat the unit contains an internal maintenance free rechargable battery that will keep the time date position and GPS almanac alive inside the GPS receiver for ca 3 hour long power failures 2006 Jackson Labs 5 FireFox Synthesizer User Manual J a ck S on Labs After a certain time the voltage on the battery will drop to a level at which the GPS real time clock ceases to run The GPS unit will continue to hold the data in its memory for several days after this happens but the time and date will not be updated anymore This may cause the unit to turn on with an internal time date that is stale old by several days causing the GPS receiver to search for a satellite constellation that presently does not exist This may cause the GPS receiver to require a significantly longer time to first fix TTFF than if the battery was completely discharged It may take up to 12 hours for the GPS receiver to start the Auto Survey process under this fault condition To speed up the TTFF in this condition the user may configure the unit to be remotely controlled Communicatio
28. d as an SCPI controlled or manually controlled RF sweeping signal generator with leveled output The output signal level is highly accurate within 1dBm and the frequency update rate is in excess of 500 updates s in Software controlled mode and 125Mupdates s in Hardware controlled mode Sweeps can range from 0Hz to 1640MHz and several sweep modes are available including single sweeps and repetitive sweeps 2 5 2 1 SOURce SWEep MODE lt HW SW gt 32 O 2008 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs DWELI lt numeric value gt POINTS lt numeric value gt TIME lt numeric value gt STEP GENeration lt ANALog STEPped gt SPACing lt LINear LOGarithmic gt DIRection lt UP DOWN UPDOWN gt COUNt lt numeric value gt This command controls the Frequency sweep functionality of the FireFox The RF output power is leveled during frequency sweeping and the output level is set by the power command described in Section 2 5 3 1 Leveling the RF output power allows the frequency sweeping mode to be used to measure frequency responses of filters amplifiers cables etc with a very high level of accuracy FireFox sweeps can also be used with Spectrum Analyzers and Directional Couplers to provide full Network Analyzer functionality 2 5 2 2 SOURce SWEep MODE lt HW SW gt This command selects between the Software Controlled sweeping mode and the Hardware Controlled sweeping mode S
29. dbm depending on the frequency in relative output mode when setting 0 to 100 output power LVDS digital differential 50 Ohm signal on two SMA connectors Typically terminated by a 100 Ohm resistor between the two signals This signal is used in modem high speed interfaces such as LCD panels FPGAs memories etc These signals can also be used as standard RF signals when connected via an AC coupler output at ca 3 to Sdbm or as PECL differential signals when terminated to ground via two 50 Ohm resistors The signal is being driven from 10MHz to 1640MHz with an under range down to 2MHz BNC comector with a 10MHz very low phase noise Reference clock output digital CMOS 3 3V level This signal in combination with a CMOS 3 3V level 1PPS output is similar to other frequency references on the market and may be used as an in house frequency standard to drive other instruments for better than 10 12 long term performance Broadband 2GHz analog mixer A general purpose broadband mixer with over 350MHz bandwidth is available on the front panel This can be used in receiver transmitter or transponder applications Any RF signal up to 2GHz may be mixed with an LO signal up to 2GHz and produce a 350MHz bandwidth IF signal The RF signal input can be driven by a 20dbm to 10dbm signal The LO input can typically be driven by the Synthesizers own RF type output see above at Odbm To avoid damage a signal amplitude maximum of 10dbm should n
30. der to be able to control the internal M12 GPS receiver via WinOncore12 1 Connect the RS 232 cable supplied with your FireFox Signal Generator to your PC s COM 1 or COM 2 serial port and to the FireFox Signal Generators back panel RS 232 port labeled RS 232 GPS see Figure 1 6 2 Go to the FireFox menu SETUP gt COMMUNICATION gt GPS and choose REMOTE You must stay in the REMOTE menu in order to have external access to the GPS receiver Leaving the REMOTE menu will disable external access to the GPS receiver 3 Download install and start the WinOncore12 program on your PC and setup the communication port under the OPTIONS gt COMMUNICATIONS gt PC COMMUNICATIONS WinOncore12 menu Set the port you choose and select 9600 Baud communications 4 You should now see Satellite status information and be able to control the receiver with the WinOncorel2 program Settings such as Satellite Mask Angles etc will be stored in the internal GPS receiver battery backed NV memory 1 4 15 Entering the Calibration Mode The FireFox Signal Generator does not need to be frequency calibrated it continuously calibrates its internal time base using the built in GPS receiver The analog RF Output BNC connector on the front panel does need periodic calibration to achieve the specified level accuracy when in absolute dBm mode Press the SETUP gt CALIBRATION menu button to enter calibration mode Please see Chapter 4 for an in depth discussion
31. e FireFox handle GPS hold over mode Other commercially available reference timing receivers boast of their long hold over circuitry performance when not being able to receive any satellites The FireFox synthesizer uses a slightly different approach Instead of hoping for the best and designing circuitry for hold over mode when the receiver cannot receive GPS satellites due to jamming or due to the low sensitivity of competitive receivers the FireFox uses an optimized design and the best receiver available on the market to avoid any GPS receiver drop outs in the first place Once the receiver has established its position and is in position hold mode only one satellite needs to be seen by the receiver for the FireFox synthesizer to work properly The sensitivity and jamming immunity of the FireFox GPS receiver is absolutely exceptional Thus long hold over periods will likely never occur even if the antenna is just placed in a window sill 3 5 3 Can the internal GPS receiver be connected to a PC The FireFox internal microprocessor controls and configures the GPS receiver with default settings during power on A menu option allows access to the GPS serial signals via an RS 232 connector on the back panel to override these default settings This connector may be used to optionally control the GPS receiver setup via Motorola s WinOncorel2 PC software All features of the internal Motorola M12 receiver can be checked and controlled via a simple n
32. e remote control mode using the SCPI commands is disabled by default and needs to be initiated via manual key commands The FireFox SCPI remote control is activated by setting the SCPI Mode tag located under the SETUP COMMUNICATION menu option The user can access this menu option by using the front panel keypad The FireFox Signal Generator will remain in SCPI mode until the key Menu is pressed on the keypad By entering the SCPI mode the SCPI command RST is automatically executed thus initiating the unit into a default state 2008 Jackson Labs 29 FireFox Synthesizer User Manual Ja ck S on Labs 2 4 Serial Communication Setup The RS 232 serial configuration used in the FireFox Signal Generator is 8 bit word length no parity 1 stop bit A Windows Hyper Terminal is sufficient to transfer commands into the FireFox Signal Generator turn echo on as described in section 2 5 8 1 2 to see your typing 2 5 Support for IEEE488 2 Mandated Commands 30 The SCPI standard requires several commands to be implemented for full standard compliance The following list describes these mandated commands These commands are not required for the operation of the FireFox Signal Generator they are only provided for standard compliance IDN This commands identifies the Firefox and will display the following string Jackson Labs FireFox Synthesizer Firmware Rev x x RST This command sets back the default values of the Frequency and Swe
33. e to be used to properly format the signal The mixer is also useful when trying to receive high frequency signals see the following example An FM modulated signal at 1 40GHz is to be received using the FireFox and a standard FM radio The input signal has to be transformed from 1 40GHz to 100MHz to be receivable by the FM Radio For this example we will select a Local Oscillator LO Frequency of 1 50GHz The LO input is simply driven by the FireFox RF output signal via a BNC jumper cable so the FireFox is set to generate the 1 5GHz The received RF input signal is then connected to the RF input Mixing the 1 5GHz LO frequency with the 1 4GHz RF signal will generate a 100MHz mixing product the Intermediate Frequency or IF signal which is basically the RF signal shifted to 100MHz The IF output can now be connected to the FM radio tuned to 100MHz The received signal will now be audible by the radio 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs Typical signal levels at the mixer inputs are 20dBm to 5 dBm for the RF input and Odbm for the LO input Care must be exercised to avoid driving the Mixer RF and LO inputs above 10dbm Driving the inputs above this level could damage the mixer The mixer can be disabled in the menu settings to reduce potential interference 1 4 12 Storing and Recalling Setups The FireFox unit can store up to 10 independent setups in its internal Non Volatile memory To store rec
34. eceiver FAQs These FAQs discuss the GPS sub section the GPS Disciplined Oscillator or GPSDO of the FireFox synthesizer 3 5 1 Why did you include a GPS receiver in the FireFox synthesizers Before FireFox customers had to purchase a separate GPS disciplined Cesium or Rubidium frequency reference and a synthesizer unit and connect these together to get both accuracy and resolution The cost of these units easily exceeds 5000 and leaves the user with two power hungry clunky units that have to be connected to each other FireFox uses an internal very high end Motorola M12 timing receiver which is specialized for reference timing applications The GPS timing receiver provides the best available timing reference signal on the market by compensating for the receivers location thus providing a timing signal that is synchronized to within 20ns of UTC anywhere in the world This timing signal is used to synchronize a high end low noise 10MHz OCXO to UTC which itself provides the reference signal to all FireFox PLLs and the DDS Combining both the GPS disciplined Frequency reference and the Synthesizer functionality into one unit allows exceptional accuracy the frequency accuracy is much better than 10 12 long term for the 10MHz internal OCXO reference while at the same time reducing the size cost power consumption and failure rate of the units O 2006 Jackson Labs 47 FireFox Synthesizer User Manual J a ck S on Labs 3 5 2 How does th
35. eceiver with Auto Survey position averaging position hold mode and T RAIM signal quality assurance algorithm provides this signal 1 6 3 GPS Disciplined OCXO Reference The FireFox ultra low phase noise internal 10MHz OCXO is constantly drift corrected by comparing its output frequency to the Caesium based GPS satellite timing signals The GPS satellites are maintained by the U S Naval Observatory for more information see also http tycho usno navy mil The GPS signals are received by a specialized high end Motorola GPS timing receiver that has a better than 20ns accuracy per second to UTC on its 1PPS output signal This receiver is housed in its own metal enclosure to improve its immunity to thermal changes and external interferences Maintaining frequency synchronization between the internal OCXO and the average GPS UTC time signal allows the FireFox synthesizer to achieve its excellent frequency accuracy without ever requiring calibration NIST traceability of the GPS timing reference is available at Attp Mf nist gov service gpscal htm The FireFox synthesizer 1PPS output can be used to discipline external Cesium or Rubidium references with NIST traceability A complete USNO test report of the GPS timing receiver performance is available upon request The USNO report shows a measured overall offset to the USNO master timing reference IPPS signal of typically only 2ns after 300 hours of operation Figure 1 6 shows the GPS antenna connection t
36. ed IF output bandwidth lt 4 5MHz to gt 350MHz LO input sensitivity lt 10dBm RF input sensitivity lt 10dBm Damage level 14dBm RS 232 Ports GPS RS 232 System RS 232 Firmware Rev 3 0 and later Motorola WinOncorel2 compatible SCPI 99 compatible 2006 Jackson Labs Table 1 2 FireFox Key Specifications Typical FireFox Synthesizer User Manual Ja ck S on Labs Item Description Specification 1PPS GPS Port CMOS compatible BNC output on rear panel Rising 0 3 3V edge synchronized to UTC Do not terminate use a 50 Ohm open ended cable Rising edge can be shifted in 1ns steps via WinOncorel2 software to compensate for antenna cable delay Power Consumption 100V 230V 43Hz 65Hz AC steady state lt 20W 12 0V input option steady state 7 5W 8 5W Table 1 2 FireFox Key Specifications Typical 1 5 2 Typical Allan Deviation Plots Allan Deviation oy t 10 10 10 11 Hit A i LA dll E NI L Le 10 12 10 2 10 1 10 10 10 103 104 105 Averaging Time t seconds Figure 1 2 Typical Allan Deviation of 5MHz front panel output with default OCXO The FireFox Allan Deviation in Figure 1 2 was measured by an internationally recognized independent test lab using a Hydrogen Maser as a reference compared to the FireFox Signal Generator front panel RF output set to 5 0MHz at 7dbm Measurements were done using a TSC 5110A Time Interval Analyzer 18 2
37. ed indefinitely in the NV memory even when power is removed from the system 1 6 8 Frequency Sweeping The unit can be used for arbitrary frequency sweeping with linear or logarithmic sweep modes Start Stop and sweep speed settings are entered into the FireFox synthesizer via the keypad Sweeps can be repetitive or single shot The RF output is leveled during sweeping 1 6 9 Differences between Desktop unit and OEM module The FireFox OEM module is identical to the circuit board used in the FireFox desktop unit The desktop unit adds a power supply and a high quality metal enclosure with keypad LCD and connectors to the FireFox OEM module allowing the unit to be used on a lab bench with easy access to all IO connections The FireFox OEM module allows integration of the unit in space constrained applications where control via the serial ports or fixed frequency settings are required The FireFox OEM module operates from a single 12 0V DC power supply and consumes less than 8W of power while the FireFox desktop unit can operate from 110V to 240V AC An optional 12 0V power connector can be added to the FireFox desktop unit by the factory to allow mobile battery powered operation See figure Figure 1 7 and Figure 1 8 of the FireFox OEM module 2006 Jackson Labs 25 FireFox Synthesizer User Manual J a ck S onj Labs Figure 1 7 FireFox OEM Module System Board Bottom 26 2006 Jackson Labs J a C K S onj FireFox Synthesizer User M
38. ep subsystem No signal is being generated Power is set to the minimum of 40dBm and the phase offset is set to 0 Degrees The serial speed and echo status remain unchanged after a RST command ESR This command queries the contents of the Standard Event Status register SESR as defined by IEEE488 2 Only the followings bits are managed e bit 4 Execute error This bit is set whenever an error occurred in the execution of a command bit 5 Command error This bit set whenever a command with a wrong syntax is received e bit 7 Power On This bit is set at all time ESE This command sets the contents of the register Standard Event Status Enable register It is a mask specifying which bit of the Standard Event Status register should be displayed in the ESR register ESE This command queries the value of the register SESE CLS This command clears the register OPER SESR and ESE O 2008 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs OPER This command is the query of the OPERation status register Only bit3 Sweeping is actually currently managed All the other bits are set to zero 2 5 1 Frequency Subsystem The FireFox Signal Generator has two output operating modes Continuous Wave CW and Sweeping Mode The Frequency sub system gives the user the capability to program the front panel static output frequency when the unit is in Continuous Wave CW mode and allows the selection of sweep par
39. equency Sweeps 1 4 10Monitoring the Instrument Status 2006 Jackson Labs FireFox Synthesizer User Manual CO CO O CO O O O0 Oo OO OO Oo O1 O1 O1 EE CO NN NON ND FireFox Synthesizer User Manual 1 4 10 10CXO Status 1 4 10 2GPS Status 1 4 10 3Sys Config 1 4 11Using the External Mixer 1 4 12Storing and Recalling Setups 1 4 13Using the GPS and OCXO Reference Outputs 1 4 13 1GPS Receiver 1PPS Output 1 4 13 20CXO Timing Reference ee 1 4 14Advanced GPS Setup 1 4 14 1Factory Reset 1 4 14 2GPS TRAIM Filter 1 4 14 3Controlling the M12 GPS Receiver using a PC 1 4 15Entering the Calibration Mode 1 4 16Entering SCPI Remote Control Mode 1 5 FireFox Desktop Typical Specifications 1 5 1 Specification Summary 1 5 2 Typical Allan Deviation Plots 1 5 3 Block Diagram by 1 6 Detailed Overview 1 6 1 Applications 1 6 2 Signal Generator Outputs 5 1 6 3 GPS Disciplined OCXO Reference 1 6 4 DDS Synthesizer 1 6 5 RF Output Buffer 1 6 6 User Interface 1 6 7 NV memory 1 6 8 Frequency Sweeping 1 6 9 Differences between Desktop unit and OEM module 1 6 10Generic Mixer 2 SCPI Remote Control 2 1 RS 232 SCPI Remote Control 2 2 SCPI Introduction 2 3 Initiating SCPI Control Mode 2 4 Serial Communication Setup 2 5 Support for IEEE488 2 Mandated Commands 2 5 1 Frequency Subsystem 2 5 1 1 SOURce FREQuency S
40. equency accuracy from an internal GPS receiver that feeds Cesium quality long term stability reference signals to the Synthesizer unit The unit does not require maintenance as Cesium oscillators do Cesium references need expensive physics package replacements every 5 years or less and provides better long term time base accuracy than non GPS disciplined Cesium references This manual describes the FireFox GPS disciplined broadband synthesizer module and Desktop unit The FireFox GPS Disciplined broadband signal generator is available as a benchtop unit or OEM module Both units use a built in highly stable GPS disciplined Oven Controlled Crystal Oscillator GPSDO The FireFox Synthesizer for the first time combines sine wave and digital outputs and a highly stable frequency reference in one instrument This combination can generate digital CMOS and LVDS PECL square waves and analog RF sine wave outputs from DC to 1 64GHz with better than 1E 012 long term frequency accuracy O 2006 Jackson Labs 1 FireFox Synthesizer User Manual J a ck S on Labs 1 2 Certification Jackson Labs certifies that this product met its published specifications at time of shipment 1 2 1 Warranty This Jackson Labs hardware product is warranted against defects in material and workmanship for a period of 1 one year from date of delivery During the warranty period Jackson Labs will at its discretion either repair or replace products that prove to be defective
41. eveled output signal indicated in dBm or a relative output level 0 100 via the keypad The maximum relative output level varies with frequency The RF output can be periodically calibrated using an Agilent E4418B or E4419B power meter and an Agilent 8482A power sensor connected to the FireFox synthesizer Calibration is fully automatic and can include user cabling and amplifiers etc to compensate for cable losses 24 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 1 6 6 User Interface A 5 key keypad is used to control the settings of the FireFox synthesizer Status is displayed on a 20x4 character LCD display The keypad is used to select frequency amplitude and menu settings that control the GPS receiver internal memory settings the DDS sweep features and the status information display Frequency and amplitude settings are controlled via UP DOWN and LEFT RIGHT keys by simply selecting the sub range with the LEFT RIGHT keys and then setting the desired value by pressing and holding the UP DOWN key See Figure 1 1 showing the front panel of the FireFox desktop unit 1 6 7 NV memory All user selections including up to 10 user profiles are stored in non volatile memory The GPS receiver stores its satellite almanac the present position and time date information in battery backed SRAM GPS settings can be maintained for several days typically without an external power source while all other settings are stor
42. ght key is pressed Every sweep from F1 to F2 or F2 to F1 will have a duration D The sweep settings are accessible directly from the main menu SWEEP 1 4 10 Monitoring the Instrument Status 1 4 10 1 OCXO Status The FireFox Signal Generator allows its internal status to be monitored via the STATUS OCXO menu item The OCXO temperature the OCXO EFC DAC value the estimated 30 minute Allan Deviation and the GPS pulse number can be monitored when accessing this menu item The EFC status shows the value of the present DAC setting from 0 to 100 This value is typically between 50 and 60 and should only change slowly over time The Freq Est number displayed shows the estimated Allan Deviation for a measurement interval of 30 minutes 1800s This number is calculated by taking the phase offset measurement between the GPS 1PPS output and the internal OCXO 1PPS signal waiting 30 minutes then comparing this value to the present phase offset and calculating the error in one minute updates The OCXO temperature shown is measured at the outside of the metal cage of the OCXO and should typically be between 45 and 65 Degrees Celsius The 1 PPS pulse count shows how many 1PPS pulses have been received from the GPS timing receiver At least 3600 pulses need to be received for the Freq Est to be calculated correctly 1 4 10 2 GPS Status The GPS status menu item will display the stored GPS hold mode position and altitude The GPS receiver firmware
43. gt e POW 0 lt cr gt Both command formats will configure the FireFox Signal Generator to output the Frequency 123 456MHz with an amplitude of 0dBm 2 6 2 Configuration and Settings Query Most commands can be queried by using the question mark symbol behind the command e pow would return the output power value to the RS 232 port e freq would return the frequency The complete command syntax may also be used in compliance to the SCPI standard 2008 Jackson Labs 39 FireFox Synthesizer User Manual J a C k S onj Labs e SOURce POWer 40 2008 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs FAQs 3 1 Overview The following pages try to answer commonly asked questions Please refer to the online FAQ at www jackson labs com for the most recent FAQs 3 2 General FAQs General FAQs discuss topics of general interest related to the FireFox operation 3 2 1 How can the FireFox Synthesizers offer such high performance for such a low price From the outset the FireFox synthesizers were designed for the lowest cost possible while still beating competitive units in quality They eliminate unnecessary features the competition may offer yet focus on providing the best quality essential features that customers need The FireFox synthesizers use the latest RF chips Microprocessors FPGA s and discrete components available on the market to significantly reduce the component count and thus cost while
44. h any of the buttons on either unit during the calibration procedure 60 2006 Jackson Labs J a C k S 6 n abs FireFox Synthesizer User Manual E4418B FPM Series Power Meter Figure 4 8 Agilent power meter display during calibration During calibration the Agilent power meter will display the momentary frequency and level of the output signal being measured The frequency will vary from 2MHz to 1640MHz see Figure 4 8 Please note that the Power meter has been turned into remote mode by the FireFox RMT is displayed in the LCD and the unit is communicating as evidenced by the RX TX indicators The Power meter may sometimes also display the ERR indicator this indicator can be disregarded Please note that the power meter indicates that it is using sensor calibration table 2 with the 2 indication in the LCD display under the frequency You must enter and enable the calibration table properly to avoid calibration errors 2006 Jackson Labs 61 FireFox Synthesizer User Manual J a ck S on Labs 62 ZX AVOID STATIC DISCHARGE Figure 4 9 Successful Calibration results The unit will display a message as shown in Figure 4 9 when the calibration is finished successfully Calibration data is only stored in Flash memory at the end of the calibration when this message is displayed N B TO USE THE FIREFOX YOU MUST UNPLUG THE UNITS POWER AFTER AND ONLY AFTER THE CALIBRATION IS FINISHED AND YOU SEE THE MESSAGE IN Figure 4
45. hat can be set via the front panel keys in the frequency setting menu This setting will also affect sweep modes and memory recall modes 2006 Jackson Labs 9 FireFox Synthesizer User Manual Ja ck S on Labs The unit will not generate Frequencies above the limit Frequency selected in this menu item The limit Frequency will be stored in non volatile memory until changed in this menu item 1 4 8 2 Power Unit In the SETUP gt OUTPUT gt POWER UNIT menu the user may select either a relative power output ranging from 0 to 100 ofthe units power output capability or an absolute output power selected in dBm between 40dBm to 10dBm Setting relative mode is useful if the maximum power output at any given frequency is desired from the analog RF Output BNC connector on the front panel The maximum output power in relative mode can range from 5dBm to over 18dBm depending on the output frequency Setting absolute mode will allow the unit to generate RF signals with high level accuracy typically within 0 2dBm at an output power of OdBm The range of the output power is limited to 40dBm to 10dBm in absolute mode This setting only affects the analog RF Output BNC connector on the front panel All other signal outputs remain unaffected by this setting 1 4 8 3 Power Limit In the SETUP gt OUTPUT gt POWER LIMIT menu the user may limit the maximum possible analog RF Output Power that can be set via the front panel keys in the freq
46. hat requires a highly stable and accurate analog sine wave signal or digital clock signal It combines a function generator signal generator and GPS Disciplined frequency reference into one small unit As a bonus the unit also includes a generic non dedicated 2GHz mixer usable for building receivers or up down converters The units outputs are optimized for the following uses High power HCMOS 3 3V 5Vpp digital output signal DC to 390MHz This signal is a typical CMOS output signal that can drive an un terminated 50 Ohm transmission line at either 5V or 3 3V peak selectable via switch on the back panel The output driver is strong enough to also drive 50 Ohn resistor end terminated transmission lines up to 2 4V 5Vpp setting which is enough signal level to switch typical 3 3V CMOS logic or TTL inputs The rise and fall times of this output are typically less than 1ns The output can typically provide 32mA of drive current This signal can 42 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs be used in any digital logic application up to 390MHz far outperforming competitive solutions allowing it to be used in SDR DDR QDR memory interfaces or as CPU master clock drivers 50 Ohm AC coupled spectrally pure RF sine wave output from 2MHz to 1640MHz Used in any type of communication applications that require a low phase noise spectrally pure output signal Adjustable from typically less than 40dbm to up to 18
47. he 1PPS output and the 10MHz OCXO reference output of the FireFox synthesizer desktop unit 2006 Jackson Labs 23 FireFox Synthesizer User Manual J a C k S onj Labs Figure 1 6 FireFox Desktop Unit Rear Panel 1 6 4 DDS Synthesizer The FireFox variable output frequency is generated by a Direct Digital Synthesizer with 48bit resolution Figure 1 5shows the block diagram of the FireFox synthesizer with the DDS module visible on the upper part of the image The DDS generates sine wave signals ranging from 10uHz to 410MHz using a 10bit DAC and a 1GHz reference input A 400MHz low pass reconstruction filter is used at the output of the DDS to reduce aliasing and improve spurious performance The output signal of the DDS drives a PLL module that multiplies the output frequency of the DDS up to 1 64GHz for output signals above 400MHz The DDS phase accumulator may be controlled by the user via the keypad to shift the output signal phase arbitrarily from 180 to 180 degrees with 0 1 degree resolution 1 6 5 RF Output Buffer The FireFox synthesizer has multiple digital outputs and one analog RF signal output This RF output is factory calibrated and leveled and the amplitude is adjustable via the keypad The output is a pure sine wave with low phase noise and low spurs and harmonics A buffer and variable gain amplifier allow signal levels above 10dbm typ with a control range down to 40dbm typ The user can either select a calibrated l
48. ility with the default OCXO O 2006 Jackson Labs 19 FireFox Synthesizer User Manual J a ck S on Labs Dole 0 18 08 Time 07 08 29 Dolo EQ 215007 of JC S ou 1 0000000e 00 Fil m RA HH cesso o foes Hg HH HA on E Tou Sigma ml 1 008 00 1 66e 08 bel 2 006400 5 91e 09 SE Sa 4 00e 00 2 01e 09 Q 100e 01 478e 1D E 2 00e 01 170e 10 4 00e 01 6 33e 11 1 006 02 2 25e 11 a 2 008 02 107e 1 a 5 03e 12 as 2 90e 12 pa 212e 12 E a 1 27e 12 E 3 65e 13 Bal 1 67e 13 ch 8 75e 14 Es SE E as Ba sa 10 10 10 10 10 10 Averaging Time T Seconds Figure 1 4 Rear Panel 1PPS output Stability when locked to GPS Tow pe 1 5 3 Block Diagram The FireFox built in GPSDO feeds a Direct Digital Synthesizer DDS which allows Continuous Wave CW frequencies from DC to 1 64GHz to be generated with 10uHz 15 digit resolution over a 1 64GHz range With the help of its internal GPS timing receiver the built in 10MHz OCXO reference achieves a better than 10 Stratum 1 long term accuracy The short term accuracy when locked to GPS is typically better than 5x107 when measured in 30 minute intervals see Figure 1 2 Please note that this Allan Deviation plot represents typical values under optimum conditions and there is typically a fairly large unit to unit spread when measuring Allan Deviation especially at measurement intervals of less than 2000 seconds Figure 1 5 shows a blo
49. item The single oven default OCXO is MTI230 0827 The double oven OCXO option is MTI270 0269 The last display item is DDS Resolution The DDS resolution is the internal resolution limit due to the 48 bit DDS setup The smallest DDS step size is 1 7764microhertz and the highest step size is 14 2109microhertz depending on the output frequency The system will generate an output frequency closest to the desired frequency with a step size displayed in the LCD 1 4 11 Using the External Mixer 12 The FireFox Signal Generator includes a general purpose mixer accessible from the front panel A mixer is used to generate a signal consisting of the difference of two input signals Mixers can be used to shift high frequency signals into lower frequency bands or vice versa As an example the FireFox Signal Generator can be used to modulate baseband video signals to RF channel frequencies Analog or Digital signals such as DVB T baseband signals can be upconverted to RF frequencies up to about 400MHz To RF modulate an I Q baseband DVB T video signal to an RF carrier of 61 25MHz simply set the RF output of the FireFox Signal Generator to 61 25MHz feed the RF output into the LO Mixer input set the RF output amplitude to OdBm making sure not to exceed the Mixer input damage level of 10dBm and feed the DVB T baseband signal into the mixers RF input The Mixer output will now contain a DVB T modulated signal with a 61 25MHz carrier A VSB filter may hav
50. its rated accuracy Cold power on requires ca 5 hours of operation to achieve UTC lock and the unit is kept operating to avoid this initial delay In order to stay locked to UTC the OCXO oscillator receives constant drift corrections from the GPS timing receiver Over time the drift errors of the OCXO and the GPS receiver will decrease and the system errors that need to be corrected will thus decrease as well The unit only has to lock to UTC once after power up and will remain locked as long as GPS signals are received and power is supplied Power consumption is typically low at 18W when operating from 110V AC and less than 10W when running from a 12V DC supply 3 3 Application Usage FAQs The following FAQs give useful hints in operating the FireFox Signal Generators 3 3 1 What is the difference between the FireFox Desktop unit and the FireFox OEM PCB The FireFox Desktop unit uses the same FireFox OEM board that is also sold separately The desktop unit includes a Swiss made enclosure a power supply an LCD Display a Keypad and external connectors for all the I O connections available on the FireFox OEM board The FireFox OEM board is typically installed into a user enclosure and statically set to a fixed frequency or controlled via the built in RS 232 serial port 3 3 2 What applications is the FireFox Synthesizer designed for The FireFox synthesizer has five independent outputs to allow it to be used in almost any application t
51. kson m FireFox Synthesizer User Manual Document 0012008 004 Date 10 April 2008 FireFox Synthesizer User Manual Copyright O 2008 Jackson Labs ksony Jac son a Table of Contents 1 Introduction 1 1 Overview 1 2 Certification 1 2 1 Warranty 1 2 2 Limitation of Warranty 1 2 3 Exclusive Remedies 1 2 4 Safety Summary 1 3 General x 1 3 1 Environmental Conditions 1 3 2 Line Power and Grounding 1 3 3 Line Fuse 1 3 4 Do not operate the Instrument i in an 1 Explosive Atmosphere 1 3 5 Keep away from Live Circuits 1 3 6 Do not Service or Adjust alone 1 3 7 Do not exceed Ratings 1 3 8 Do not substitute parts or modify the Instrument 1 3 9 Operational Warning 1 4 Quick Start Instructions 1 4 1 Connecting the instrument 1 4 2 Initializing the GPS 1 4 3 Setting up the GPS a 1 4 3 1 GPS Time Offset do vi 1 4 3 2 Selecting Metric US Mode 1 4 3 3 GPS Auto Survey 1 4 4 Setting the Frequency 1 4 5 Setting the RF Amplitude f 1 4 6 Using the CMOS and LVDS outputs T 1 4 6 1 Connecting a cable to the LVDS Outputs 1 4 6 2 Connecting a cable to the CMOS Output 1 4 6 3 Selecting the Front Panel CMOS cia a 1 4 7 Setting up the DDS 1 4 7 1 Setting the Phase Offset 1 4 7 2 Mixer ON OFF 1 4 7 3 FRACT ON OFF 1 4 7 4 Noise Spur Optimization 1 4 8 Setting up the Output 1 4 8 1 Frequency Limit 1 4 8 2 Power Unit 1 4 8 3 Power Limit 1 4 9 Setting up Fr
52. l they can be repaired by qualified service personnel 1 3 9 Operational Warning Do not operate the FireFox desktop unit without its covers in place Life line voltages are present inside the case and could cause bodily harm or death when the unit is operated without its covers in place 4 2006 Jackson Labs J a C k S O n abs FireFox Synthesizer User Manual 1 4 Quick Start Instructions The following paragraphs describe the basic operational procedures to use the FireFox unit The user interface for the FireFox OEM board and the FireFox Desktop unit are essentially identical Figure 1 1 FireFox Desktop Unit Front Panel 1 4 1 Connecting the instrument Connect the AC power cord to the rear panel power connector The unit will operate from 100V to 240V AC See Figure 1 6 for the FireFox rear panel connectors Connect the factory supplied GPS antenna to the GPS BNC connector on the rear panel By default the unit is configured to supply 5V to the GPS antenna Jumper JP4 inside the unit can be used to select 3 3V antenna interfaces Please note that opening the unit will void the factory warranty 1 4 2 Initializing the GPS Every time the FireFox unit is moved it is recommended to enable the GPS Automatic Site Survey mode or AutoSurvey in order to reacquire its exact new position The autosurvey algorithm averages a total of 10000 valid position fixes and typically takes about 2 3 hours to finish Once the position is surveye
53. losest frequency that the DDS can generate The frequency difference between the desired setting selectable in 10uHz steps and the actual frequency being generated causes a very small error 52 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs Auto Calibration 4 1 Introduction The FireFox Synthesizer does not require frequency calibration it continuously self calibrates its internal OCXO by using the GPS timing receiver The FireFox Synthesizer RF output level is factory calibrated and it is suggested that the user re calibrates the RF output once a year to maintain an accurate output level The unit can auto calibrate itself using an external power meter It contains firmware to drive an Agilent E4418B or E4419B power meter connected to an Agilent 8482A power sensor The following paragraphs describe how to connect the power meter to the FireFox and initiate the auto calibration procedure 4 2 Power Meter Setup The power meter and FireFox synthesizer have to be warmed up for one to two hours before the auto calibration is started Plug in and turn on the power meter and plug in the FireFox synthesizer into the wall power outlet After warm up and prior to starting the auto calibration the Agilent power meter needs to be properly prepared to reduce the calibration error 4 2 1 Updating the Agilent Sensor Cal Table The Agilent 8482A sensor has a sensor calibration table placed on its bottom The dat
54. m 40dBm to 10dBm The output power at the RF BNC connector is accurate to within 1dBm of the value displayed in the LCD over the units frequency range 0 2dbm typical accuracy 3 4 Hardware FAQs These FAQs describe the hardware implementation and connectivity requirements of the FireFox Signal Generators 3 4 1 The rear panel says Do not terminate CMOS outputs Can the outputs drive 50 Ohm end terminated cables The FireFox uses high speed strong CMOS drivers to drive the rear 1PPS output the 10MHZ output and the front CMOS output These outputs are designed to drive unterminated open ended 50 Ohm cables as well as 50 Ohm end terminated cables The outputs can drive a minimum of 24mA Using unterminated cables yields 3 3V logic levels while using 50 Ohm end terminators will reduce the output amplitude by ca 50 making them non TTL compatible thus the warning label The CMOS output drivers used in the FireFox provide both very low jitter and a very small 1PPS delay in the order of a couple of nanoseconds They can drive both AC coupled sine wave 50 Ohm inputs as well as digital TTL CMOS inputs and thus provide more flexibility than traditional sine wave outputs O 2006 Jackson Labs 45 FireFox Synthesizer User Manual J a ck S on Labs 3 4 2 Can the FireFox system be powered by a battery The FireFox system requires a regulated 12 0V power supply to operate properly A power source such as a Lead Acid type batte
55. n gt GPS gt Remote To do this connect a PC to the GPS Serial connector on the back of the unit and use WinOncore12 to set the time and date of the GPS receiver WinOncore12 has a configuration wizard for this purpose see the FAQ GPS section on www jackson labs com for information on where to download WinOncore12 1 4 3 Setting up the GPS 1 4 3 1 GPS Time Offset The FireFox Signal Generator requires the user to set the political time offset to GMT time Enter the SETUP gt GPS gt GPS TIME OFFSET menu and select between 12 to 12 hours of time offset to Greenwich Mean Time GMT 1 4 3 2 Selecting Metric US Mode The unit may display GPS height time and date in either Metric or US mode Select the SETUP gt TIME gt US METRIC menu to change the setting of the relevant GPS data in the LCD Display 1 4 3 3 GPS Auto Survey Enter the SETUP gt GPS gt AUTO SURVEY menu to start the GPS Auto Survey mode This will initiate the GPS receiver to build an average position using 10 000 position readings and to store this average position in its memory to improve the timing accuracy Operating with the averaged position is called Position Hold mode Pressing the enter key in this menu will re initiate the Auto Survey mode The FireFox will indicate the Auto Survey mode by displaying AS in the main frequency setting window above the STAT indicator Operating in Position Hold mode is indicated by an OK display above the STAT
56. nector This pulse is derived from the Motorola M12 GPS Timing receiver It does exhibit the typical M12 sawtooth waveform which may be compensated by using the Motorola Clock Granularity Message available on the rear panel GPS RS 232 port See the Motorola M12 documentation about details of how to use these two outputs The rear panel 1PPS output is buffered by a high speed 3 3Vpp CMOS output and this output should typically drive an open ended 50 Ohm transmission line cable Terminating the output with a 50 Ohm resistor will not damage the output but will significantly reduce its output voltage swing The CMOS buffer adds ca 6ns of Tpd propagation delay to the GPS receivers 1PPS output signal this delay may be compensated in the receiver by using the Antenna Cable Delay setting available when connecting the WinOncore12 software to the GPS receiver See section 1 4 14 3 and section 3 5 3 for details about the WinOncore12 software 2006 Jackson Labs 13 FireFox Synthesizer User Manual J a ck S on Labs 1 4 13 2 OCXO Timing Reference Output The rear panel 10MHz time base reference output is highly accurate and disciplined by the GPS receiver This output is driven by a high speed CMOS driver with 3 3Vpp output drive voltage This output may either drive a non terminated 50 Ohm transmission line cable or it may drive an end terminated cable The output voltage will be reduced by 50 if the BNC cable is end terminated with a 50 Ohm resi
57. nit Typically LVDS signals are connected to 50 Ohm transmission lines cables and differentially end terminated with a 100 Ohm termination resistor between the Positive and Negative LVDS signals The user may also end terminate the signals individually to Ground using 50 Ohm end terminators The output voltage levels will change slightly when terminating to Ground By using 50 Ohm ground terminated cables it may be possible to drive PECL inputs A series capacitor may also be used to remove the LVDS DC Offset present on the LVDS SMA connectors The signal swing on the two LVDS connectors is approximately 300mV peak on each output and this may be used to drive two independent analog inputs with ca 7dBm level when connected via AC coupling 1 4 6 2 Connecting a cable to the CMOS Output The FireFox CMOS output is designed to drive a 50 Ohm transmission line or cable without any end termination open ended cable Voltage levels are up to 5Vpp when using open ended cables The FireFox CMOS output may also drive 50 Ohm end terminated cables without damage and with a slightly more than 50 reduction on the high level output voltage The rise and fall times of the FireFox CMOS output are on the order of 1V ns or faster Please note that the CMOS output is low pass filtered for output frequencies below 30MHz to reduce DDS generated spurs above 30MHz and thus to reduce the output jitter The CMOS output provides the output signal with the least spurs p
58. nit and the FireFox OEM PCB 42 3 3 2 What applications is the FireFox Synthesizer designed for 42 3 3 3 Can the FireFox system keypad be locked 43 3 3 4 How come the Frequency Display doesn t let me select the exact Frequency need 43 3 3 5 How come the display shows UNCAL below 1H2 44 3 3 6 What do the LED s in the front panel indicate 44 3 3 7 What do have to do to move the FireFox unit to a different location 44 3 3 8 What happens to the FireFox settings when the power is turned off 45 3 3 9 How accurate is the output power on the RF output connector 45 3 4 Hardware FAQs 45 3 4 1 The rear panel says Do not terminate CMOS outputs Can the outputs drive 50 Ohm end ter minated cables 45 3 4 2 Can the FireFox system be powered by a battery 46 3 4 3 What are the mixer connections on the front panel used for 46 3 4 4 How can calibrate the FireFox Signal Generator 46 2006 Jackson Labs iii FireFox Synthesizer User Manual 3 5 3 6 GPS Receiver FAQs 3 5 1 Why did you include a GPS re receiver in the FireFox synthesizers 3 5 2 How does the FireFox handle GPS hold over mode 3 5 3 Can the internal GPS receiver be connected to a PC 3 5 4 can connect to the GPS receiver from my PC but cannot change any settings 48 3 5 5 What is the GPS Auto Su
59. o not include the benefits of position hold mode and T RAIM see above Their tracking filters need to be very wide to allow for speed and directional changes translating into much larger inaccuracies in the timing reference output The timing receiver is typically stationary and thus allows for much smaller bandwidth tracking filters increasing the timing solution accuracy significantly Comparable navigational receivers have a typical accuracy of 100ns rms whereas the receiver used in the FireFox units has a down to 10ns or better 1 Sigma timing resolution due to its optimized small bandwidth tracking filters 2ns solutions are possible when using optional sawtooth correction The FireFox units further increase the accuracy of the timing solution and the receiver sensitivity by enclosing the receiver into a shielded metal can to mitigate the effects of temperature changes and EMI and by rigorously filtering all power supply voltages prior to entering the timing receiver 3 5 8 What types of GPS antennae are supported The FireFox system supports both 3 3V and 5V GPS antennae via a standard BNC connector Jumper JP4 on the PCB can be set for either 3 3V or 5V output Many 5V rated antennae will also work with a 3 3V setting Jackson Labs recommends mounting any outdoor antennae with proper lightning precautions 3 5 9 What do the SAT and STAT items in the LCD display indicate The SAT number indicates the number of satellites that are presently
60. ot be exceeded on the RF and LO inputs 3 3 3 Can the FireFox system keypad be locked Yes the FireFox keypad can be locked with jumper JP11 located on the FireFox main PCB 3 3 4 How come the Frequency Display doesn t let me select the exact Frequency need You probably have turned off Fractional N mode see also Resolution FAQ under Performance section With fractional N mode disabled the frequency granularity that can be generated is 1 65536 of the granularity when the fractional N mode is enabled A warning message in the LCD display shows FractOff to indicate that the fractional N mode is turned off When the fractional N mode is turned off the frequency will still be increased or decreased in 10uHz steps when pressing the UP DOWN buttons but the display will show the actual frequency that can be generated by the DDS closest match to the desired frequency once the button is released The advantage of turning off the fractional N mode is that the system generates an exact mathematically deterministic frequency without residual fractional errors that are present in fractional N mode O 2006 Jackson Labs 43 FireFox Synthesizer User Manual J a ck S on Labs 3 3 5 How come the display shows UNCAL below 1Hz The DDS system resolution below 2MHz output frequencies is about 1 7764uHz The output frequency of the FireFox can be set by the user with 10uHz resolution This step size when combined with the DDS in
61. powered to keep the GPS receiver and OCXO warmed up and locked The FireFox desktop unit requires a three pronged AC power plug with proper grounding to prevent electrocution hazards All BNC and SMA connector shields are grounded and should not be connected to any voltage sources To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground The instrument must be connected to the ac power supply mains through a three conductor power cable with the third wire firmly connected to an electrical ground safety ground at the power outlet Any interruption of the protective grounding conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury If the instrument is to be energized via an external autotransformer for voltage reduction be certain that the autotransformer common terminal is connected to the neutral earthed pole of the ac power lines supply mains 1 3 3 Line Fuse Fuses are internal to the instrument and are not user serviceable All repairs should be referred to a qualified service technician The FireFox OEM module uses a self resettable Polyfuse that will correct itself once the fault or overload condition is removed 1 3 4 Do not operate the Instrument in an Explosive Atmosphere Do not operate the instrument in the presence of flammable gases or fumes The instrument contains mechanical switches and relays that co
62. pplications include generating arbitrary frequencies with high accuracy and low noise for calibrating instruments operating as an in house frequency and time standard design and development of digital circuits VLSI chips memory interfaces and microprocessors designing and debugging PLL circuits and driving mixers and other RF equipments local oscillator inputs With the frequency sweep features it is possible to use the FireFox synthesizer to design Microwave equipment to measure S11 and S12 performance of filters cables and amplifiers etc The units can also be used as HAM frequency generators and for any other application where arbitrary highly precise and accurate and non standard frequencies must be generated 2006 Jackson Labs 21 FireFox Synthesizer User Manual Ja ck S on Labs The FireFox synthesizer is particularly well suited for the following applications due to its high accuracy and resolution These types of applications were previously difficult to achieve with conventional equipment Combining two FireFox units and running them at slightly different frequencies frequency offsets as low as 10uHz can be achieved between two FireFox units to test for equipment behavior and failure when two slowly drifting oscillators are driving the system This is helpful in Telecom type applications High speed research applications in which two geographically separate locations require precisely synchronized timing and frequenc
63. procedure is started by the FireFox front panel keypad Make sure the two units are connected correctly and follow the procedure below 1 Press the Menu button to enter the menu mode 2 Scroll down and enter the Setup sub menu Continued O 2006 Jackson Labs 51 FireFox Synthesizer User Manual J a C k S on Labs A AVOID STATIC DISCHARGE Figure 4 5 Entering the Calibration sub menu 3 Scroll down to the Calibration sub menu Please note that the Calibration sub menu is on the sixth level and thus not visible in the LCD display until you scroll above the top menu item or below the bottom most menu item See Figure 4 5 on how to enter the Calibration sub menu continued 58 2006 Jackson Labs J a C k S 6 n abs FireFox Synthesizer User Manual A AVOID STATIC DISCHARGE Figure 4 6 Starting the Calibration procedure l 4 Enter the Calibration sub menu 5 Two menu items are shown see Figure 4 6 Setup and Debug Entering Setup will start the actual calibration procedure Debug is used for factory testing Continued 2006 Jackson Labs 59 FireFox Synthesizer User Manual J a ck S onj Labs AVOID STATIC DISCHARGE Figure 4 7 LCD Display during calibration procedure 6 Enter Setup and verify that the LCD displays information similar to Figure 4 7 The auto calibration procedure will take several hours to finish To avoid calibration errors do not disconnect any of the cables or touc
64. put sweep FREQ MODE SWE STAR 100Mhz STOP 1Ghz POW 2 SWE MODE SW SPAC LOG TIME 30 GEN ANAL COUNt 1 O 2008 Jackson Labs 35 FireFox Synthesizer User Manual Ja ck S on Labs OUTP 1 INIT IMME Both command formats will initiate a software controlled sweep with logarithmic frequency update rate from 100Mhz to 1GHz with an RF output amplitude of 2dBm The total duration of the sweep will be 30 seconds 2 5 2 12 Hardware Controlled Sweep configuration example Complete command syntax style SOURce FREQuency MODE SWEep SOURce FREQuency STARt 10 Mhz SOURce FREQuency STOP 390 Mhz SOURce POWer 2 SOURce SWEep MODE HW SOURce SWEep GENeration STEPped SOURce SWEep POINTs 3801 SOURce SWEep DWELI 1 e 6 SOURce COUNt 10 OUTPut ON INITiate IMMe Alternative abbreviated style resulting in the same output sweep FREQ MODE SWE STAR 10Mhz STOP 390Ghz POW 2 SWE MODE HW GEN STEP POINTs 3801 DWELI 1 e 6 COUNt 10 OUTP 1 INIT IMME This command setup will initiate a hardware controlled stepped sweep with linear frequency update rate from 10Mhz to 390 GHz with an RF output amplitude of 2dBm Each frequency step will be of 390 10 Mhz 3801 1 100 Khz and will last 1 microsecond The sweep duration will last 3 8 ms and will be repeated a total of 10 times 2 5 3 Power Subsystem The Power Subsystem controls the output power of the FireFox RF output BNC connector 36 2008 Jackson Labs J a ck S on FireFox Synthesizer User Manual
65. r User Manual Labs 3 3 8 What happens to the FireFox settings when the power is turned off The FireFox units have non volatile memory that stores settings such as the frequency amplitude and menu options This non volatile memory does not require any battery backup The unit will thus power up with the last frequency and amplitude setting used prior to power down Several important settings are stored in the GPS receiver and are backed up by a rechargeable battery that has a life span of typically several days when the unit is powered off These settings are the position established by the Auto Survey function and used for position hold mode the time offset from GMT and the receiver operating mode 3 3 9 How accurate is the output power on the RF output connector The FireFox units offer two output modes on the RF BNC connectors relative and absolute output mode The operating mode is selected in the SETUP menu Relative mode allows controlling the output power from 0 to 100 of the units capability with the actual output power level varying with the frequency This mode allows the user to harvest the maximum possible output power the unit can generate at any given frequency Maximum power levels in relative mode typically range from 8dBm to 18dBm depending on the output frequency Absolute mode is used when highly accurate power levels are required Absolute mode sets the output power to factory calibrated levels ranging fro
66. r to starting the auto calibration procedure the user must connect the two instruments to each other Follow the procedures below to setup the calibration 54 2006 Jackson Labs J a ck S ony abs FireFox Synthesizer User Manual 4 3 1 Sensor Connection Connect the power sensor to the FireFox RF Output See Figure 4 2 Use a BNC to N F adapter between the power sensor and the FireFox synthesizer Figure 4 2 Connecting the power sensor to the FireFox RF output Figure 4 3 shows how to connect the sensor and BNC to N adapter in detail 2006 Jackson Labs 55 FireFox Synthesizer User Manual Figure 4 3 Power sensor connection detail The sensor may also be connected using a short cable but this will affect output linearity due to cable to connector VSWR mismatch 4 3 2 Serial Cable Connection The power meter is controlled by the FireFox system controller via a serial port Use a standard RS 232 Null Modem cable with DB 9 female connectors a suitable RS 232 cable is shipped with the FireFox Synthesizer Connect the FireFox System RS 232 output to the Agilent power meters RS 232 port See Figure 4 4 for details on how to connect the two instruments to each other 56 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs Figure 4 4 Power Meter Serial Communication connection The Calibration setup is now ready to start the actual calibration procedure 4 4 Initiating Calibration The calibration
67. resent for output frequencies below 30MHz of all of the FireFox front panel outputs 1 4 6 3 Selecting the Front Panel CMOS Output Voltage The Front Panel CMOS peak to peak output voltage is selectable via a switch on the back panel of the FireFox Desktop unit and via a Jumper on the FireFox OEM PCB The switch is visible in the upper left hand corner of Figure 1 6 Use JP12 located close to the CMOS output BNC connector to select the CMOS output voltage when using the FireFox OEM PCB The CMOS output voltage can be selected to be either OV to 3 3V or OV to 5 0V when driving un terminated transmission lines This voltage level will be reduced by slightly more than 50 when driving an end terminated 50 Ohm transmission line 8 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 1 4 7 Setting up the DDS Enter the menu SETUP gt DDS to control the internal settings of the FireFox Signal Generator RF DDS Digital Direct Signal Generator 1 4 7 1 Setting the Phase Offset Enter the SETUP gt DDS gt PHASE OFFSET menu item to control the output Frequencies phase in relation to the rear panel 10MHz time base output The user can select the phase in small increments from 180 Degrees to 180 Degrees 1 4 7 2 Mixer ON OFF The FireFox Signal Generator has a general purpose non dedicated 2GHz Bandwidth mixer built in accessible through the front panel BNC connectors This mixer can be turned ON or OFF via the SETUP
68. rol 2 1 RS 232 SCPI Remote Control Beginning with Firmware Release 3 0 the FireFox Signal Generator can be controlled remotely through a serial RS 232 connection via the built in System RS 232 port located on the back panel The supported commands are compatible with the industry standard SCPI 99 protocol The SCPI protocol originated from HP and the later IEEE GPIB standard commands and is widely used in the industry to control instruments similar to the FireFox The FireFox SCPI implementation adheres to the SCPI 99 standard and achieves compatibility with popular competitive Signal Generators and their typical command sets This assures an effortless transition of user installed legacy software with most software implementations working out of the box without any modification at all 2 2 SCPI Introduction Additional information regarding the SCPI protocol syntax can be found on the following web site http www scpiconsortium org Please refer to the document SCPI 99 pdf for details regarding individual SCPI command definitions A basic familiarity with the SCPI protocol is recommended when reading this chapter The FireFox belongs to the SCPI defined instrument Class RF amp Microwave Sources and implements all the commands necessary to control the output frequency phase power and the sweep functionality 2 3 Initiating SCPI Control Mode The FireFox Signal Generator is controlled by the front panel keypad by default Th
69. rs GPS Receiver 1PPS timing offset to UTC 1 Sigma lt 10ns 1PPS timing offset to UTC 6 Sigma lt 20ns Recommended antenna gt 18dB gain 3 3V or 5V Phase Noise At 250MHz carrier OdBm RF output 1KHz Offset 10KHz Offset 100KHz Offset 1MHz Offset lt 90dBc Hz lt 110dBc Hz lt 140dBc Hz lt 150dBc Hz 16 Table 1 2 FireFox Key Specifications Typical O 2006 Jackson Labs ksony Jac son Ra FireFox Synthesizer User Manual Item Description Specification Spurs Typical worst case spurs lt 150MHz carrier lt 45dBc Hz 150MHz 400MHz carrier lt 48dBc Hz 400MHz 800MHz carrier lt 56dBc Hz 800MHz 1640MHz carrier lt 65dBc Hz Phase adjustment lt 390MHz 390MHz 775MHz 775MHz 1640MHz 0 1 Degree steps 0 2 Degree steps 0 4 Degree steps CMOS Output BNC front panel connector DC to 390MHz into open ended 50 Ohm cable 0 3 3V or 0 5V into 50 Ohm end terminated cable lt 1 2 open ended output voltage RF Output BNC front panel connector relative mode 0 100 up to 18dBm absolute mode power 40dBm to 10dBm absolute mode accuracy at OdBm output better than 0 5dBm typi cally LVDS Output Common mode voltage 100 Ohm terminated SMA to 1 2V SMA connector Differential Output Voltage Magnitude into 100 Ohms 340mV RF Mixer Panel General purpose non dedicated mixer available via BNC front panel connectors RF and LO input range lt 4 5MHz to 2GHz Filter
70. rvey Mode 3 5 6 What is the T RAIM mode in the GPS receiver 3 5 7 Why did you not use a cheap standard GPS receiver 3 5 8 What types of GPS antennae are supported 3 5 9 What do the SAT and STAT items in the LCD display indicate a Performance FAQs 3 6 1 How does the FireFox Synthesizer offer such wide bandwidth 3 6 2 How can spur performance be increased even further 3 6 3 Does the FireFox need calibration 3 6 4 There is a Frequency Estimate display in the menus Whati is this number 3 6 5 There is a Resolution number displayed in the menus What is this number 3 6 6 There is an option to turn Fractional N mode on off What is this used for 4 Auto Calibration 4 1 4 2 4 3 4 4 Introduction Power Meter Setup 4 2 1 Updating the Agilent Sensor Cal Table 4 2 2 Using alternate Power Sensors Power Meters 4 2 3 Calibrating the Power Sensor Calibration Setup Pa 4 3 1 Sensor Connection 4 3 2 Serial Cable Connection Initiating Calibration ksony Jac son k 47 47 48 48 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs Introduction 1 1 Overview The FireFox synthesizer is a continuous wave CW a digital and a sweeping broadband signal generator with an ultra high accuracy built in frequency reference The unit can generate CW or sweep signals ranging from 0 00001Hz to 1640MHz in 0 00001Hz steps It derives its fr
71. ry will have an output voltage ranging between 11V discharged to over 14V charging and is thus not suitable for powering the FireFox board A 12 0V pre regulator with over voltage protection can be used to drive the FireFox system from a vehicle power system Contact Jackson Labs for modification of the FireFox desktop unit if a 12V DC input is required 3 4 3 What are the mixer connections on the front panel used for The FireFox unit includes a general purpose mixer accessible from the front panel A mixer is used to generate a signal consisting of the difference of two input signals Mixers can be used to shift high frequency signals into lower frequency bands This is useful when trying to receive high frequency signals see the following example An FM modulated signal at 1 40GHz is to be received using the FireFox and a standard FM radio The input signal has to be transformed from 1 40GHz to 100MHz to be receivable by the FM Radio For this example we will select a Local Oscillator LO Frequency of 1 50GHz The LO input is simply driven by the FireFox RF output signal via a BNC jumper cable so the FireFox is set to generate the 1 5GHz The received RF input signal is then connected to the RF input Mixing the 1 5GHz LO frequency with the 1 4GHz RF signal will generate a 100MHz mixing product the Intermediate Frequency or IF signal which is basically the RF signal shifted to 100MHz The IF output can now be connected to the FM r
72. s with the 1000hm resistor connecting the two differential signals together The two transmission lines may also be terminated independently to ground through two 50 Ohm termination resistors yielding PECL compatible signal levels LVDS signals are 300mVpp voltage swing and can be used to drive LVDS PECL ECL SSTL and other differential low voltage swing applications through simple termination resistor capacitor matching circuits These two outputs can also be used as two 7dbm RF LO signals with 180 Degree phase offset to each other when AC coupled and 50 Ohm end terminated 10MHz FREQUENCY REFERENCE OUTPUT unterminated CMOS 3 3Vpp A GPS disciplined low phase noise OCXO drives this CMOS output This signal may be used as a very high accuracy in house frequency reference due to its constant drift calibration via GPS satellites An unterminated 500hm coax cable is typically connected to this output The quality of this output signal approaches that of Rubidium atomic clock reference standards The long term frequency accuracy of this output exceeds that of non GPS disciplined Cesium atomic frequency standards GPS 1PPS OUTPUT unterminated CMOS 3 3Vpp A 1PPS signal positive edge active that is accurate to within 20ns of UTC is available on this connector Typically an unterminated 500hm coax cable is used to provide this signal to optional external Caesium or Rubidium atomic frequency references for disciplining purposes A GPS timing r
73. s are not intended for use in medical life saving or life sustaining applications 1 2 3 Exclusive Remedies THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER S SOLE AND EXCLUSIVE REMEDIES JACKSON LABS SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY 1 2 4 Safety Summary The following general safety precautions must be observed during all phases of operation of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Jackson Labs assumes no liability for the customer s failure to comply with these requirements 2 O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs 1 3 General 1 3 1 Environmental Conditions This instrument is intended for indoor use It is designed to operate at a maximum relative non condensing humidity of 95 and at altitudes of up to 4000 meters Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range 1 3 2 Line Power and Grounding The FireFox Desktop unit operates on a 100V to 220V 43Hz to 65Hz AC power input with typically less than 20W power consumption The FireFox OEM unit operates on a 12 0V regulated DC input with typically less than 1A input current Both units are designed to be continuously
74. simultaneously increasing the units reliability Only standard off the shelf components are used to guarantee a long life and support time of the unit Other reasons are that Jackson Labs offers and supports these units directly from the factory and does not have to maintain a high administrative or advertising overhead 3 2 2 How did you decide what features to include in the FireFox synthesizers A team of engineers each with decades of development experience designed the FireFox synthesizers The engineers asked themselves what features they would like to see and use on a laboratory bench top instrument most The requirements documents were thus designed with real life applications in mind and not with a focus on making marketing documents look good Extensive customer feedback was then incorporated to fine tune the instruments performance features and firmware Feel free to contact Jackson Labs to offer your feedback requirements suggestions and questions 2006 Jackson Labs 41 FireFox Synthesizer User Manual J a ck S on Labs 3 2 3 How long does the FireFox system take to warm up The FireFox system typically warms up to within 10 8 within 15 minutes Its specified operating parameters and GPS lock are typically achieved in less than 5 hours from a cold start when receiving satellites in position hold mode 3 2 4 Why is there no power switch on the FireFox The FireFox is designed for permanent power on to achieve
75. stor See Figure 1 2 for typical stability data for this 10MHZ output signal The unit will require between 3 to 10 hours to stabilize fully when turned on from a cold start The OCXO crystal may take up to one week to fully stabilize and to have periodic frequency shifts seize to appear especially if the unit has recently been moved shipped or has experienced significant thermal changes The 30 minute Allan Deviation Estimate of this output is available in the FREQ EST display item when entering the STATUS gt OCXO menu item This estimation is calculated by measuring the internal OCXO generated 1PPS signal phase shift to the GPS generated 1PPS signal and comparing the momentary value to the value calculated 30 minutes previously The deviation is then calculated and displayed in the LCD Typical deviation numbers when the unit has been locked and operating for several weeks are lt 5E 010 for the default OCXO option and lt 5E 011 for the Double Oven Ultra High Stability OCXO option 1 4 14 Advanced GPS Setup 1 4 14 1 Factory Reset Pressing the enter button in the SETUP gt GPS gt FACTORY RESET menu will initiate a GPS receiver Factory Reset and reset all of the stored settings of the FireFox Signal Generator Please power cycle the unit after initiating this command This command requires the user to re initiate all of the settings such as Power Unit GPS Time Offset Maximum Frequency and Maximum Power etc It is recommended that
76. ter Span 2 O 2008 Jackson Labs 31 FireFox Synthesizer User Manual J a ck S on Labs The numeric value is interpreted as in the command CW On RST the CENTer frequency is set to 1 64Ghz 2 820 0Mhz 2 5 1 1 4 SOURce FREQuency SPAN lt numeric value gt This command sets the range for the frequency sweep Changing this value will affect the Start and Stop frequency in the following way e Start Center Span 2 e Stop Center Span 2 The numeric value is interpreted as in the command CW On RST the SPAN value is set to 1 64Ghz 2 5 1 1 5 SOURce FREQuency STARt lt numeric value gt This command sets the Start frequency for the sweep configuration The change of this value will affect Center and Span in the following way e Center Stop Start 2 e Span Stop Start The numeric value is interpreted as in the command CW On RST the STARt value is set to OHz 2 5 1 1 6 SOURce FREQuency STOP lt numeric value gt This command sets the Stop frequency for the sweep configuration Changing this value will affect Center and Span in the following way e Center Stop Start 2 e Span Stop Start The numeric value is interpreted as in the command CW On RST the STOP value is set to 1 64Ghz 2 5 2 Sweep subsystem The SWEEP subsystem commands allow more detailed control of the FireFox sweep functionality than the FREQUENCY subsystem commands provide The FireFox Signal Generator can be use
77. ternal resolution of 1 7764uHz creates an average residual output error of about 0 8882uHz This error becomes more pronounced as the output frequency goes below 1Hz with a worst case performance when selecting an output frequency of 10uHz which is actually generated as 10 6584uHz The worst case error at 10u Hz output is thus a significant 6 58 With an output frequency of say 100Hz the error due to the DDS resolution is about 9x10 9 which is typically negligible but still above the FireFox OCXO accuracy when the system is locked to GPS An external CMOS TTL or PLD divider is recommended if extreme accuracy for frequencies below 100Hz is required This divider will allow the FireFox system to run the DDS at a frequency of 100Hz or higher preventing the residual DDS error from becoming significant 3 3 6 What do the LED s in the front panel indicate The front panel outputs have frequency range limits at which their outputs are valid The green LED s indicate when a particular output is valid and usable The CMOS and RF outputs are disabled outside of their operating ranges The LVDS outputs are active below their respective lower operating limit 10MHz in an under scan mode Operation of the LVDS outputs in under scan mode cannot be guaranteed and the LVDS LED is thus turned off The CMOS output is driven in over scan mode between 350MHz and 390390MHz and the CMOS LED is thus turned off in this frequency range 3 3 7 What do ha
78. tion of the Sweep subsystem INITiate CONTinuous ALL lt ON OFF gt This command puts the Sweep subsystem in continuous mode If the output is ON and the Frequency mode is SWEep the sweep is going to start and will continue until an Initiate Continuous OFF command is issued On RST INITiate CONTinuous is set to OFF 2008 Jackson Labs 37 FireFox Synthesizer User Manual J a ck S on Labs INITiate IMMEdiate This command issues a trigger event and will start the frequency sweep only if the following conditions are met e the output is ON e the Frequency mode is set to sweep If the conditions are not met at the time of the trigger the command is simply ignored The sweeping will stop when the STOP frequency is reached 2 5 7 Measure Subsystem Only the Temperature query of the Measure subsystem is implemented 2 5 7 1 MEASure TEMPerature This command is used only to query the temperature of the OCXO e MEASure TEMPerature lt cr gt 2 5 8 System Subsystem Only the Communicate command of the System subsystem is implemented 2 5 8 1 SYSTem COMMunicate SERial The supported options for this command are e BAUD lt numeric value gt e ECHo ON OFF 2 5 8 1 1 SYS Tem COMMunicate SERial BAUD lt numeric value gt This command sets the speed of the RS232 The supported Baud rates are 9600 19200 38400 57600 and 115200 bits s The Baud rate changes immediately upon reception of this command The serial speed c
79. uency step that can be generated in Fractional N mode is smaller than the 10uHz step size of the FireFox system and the value displayed in the LCD can thus be used to estimate the frequency error at any particular frequency See also the Fractional N mode FAQ 3 6 6 There is an option to turn Fractional N mode on off What is this used for This setting option allows exact cycle accurate coarse frequencies to be generated 32bit integer mode or frequencies with a much finer resolution 48bit fractional mode but with a very small fractional residual uncertainty Consider the following explanation the DDS has a 32bit integer component This integer component alongside the 1Gs s sample rate allows 232 individual frequencies to be generated without any residual error according to the following formula Fout 32bit Tuning Word 1GHz 2432 This formula is accurate for output signals from 2MHz to 390MHz Use the following formulas to determine the resolution of the output signal for the remaining frequency bands DC to 2MHz Fout 32bit Tuning Word 0 5GHz 2432 390 to 770MHz Fout 32bit Tuning Word 2GHz 2732 770MHz to 1640MHz Fout 32bit Tuning Word 4GHz 2732 The frequencies generated with fractional N mode turned off are thus cycle accurate without any slipped cycles or residual frequency error As an example consider the following example of generating a 10MHz frequency with a tuning word of 4294967296 20
80. uency setting menu This setting will also affect sweep modes and memory recall modes The unit will not generate Power levels above the limit Frequency selected in this menu item on the analog RF Output BNC front panel connector The limit Power will be stored in non volatile memory until changed in this menu item This setting only affects the analog RF Output BNC connector on the front panel All other signal outputs remain unaffected by this setting 1 4 9 Setting up Frequency Sweeps 10 The unit can be used as a sweeping signal generator The following parameters are selectable through the keypad menu e frequency start F1 from 0 to 1 64 Ghz e frequency stop F2 from 0 to 1 64 Ghz The stop frequency has to be different to the start frequency and may be selected to be lower than the start frequency e duration D of the sweep from 0 1s to 1000s with a resolution of 0 1s e sweep spacing pace linear or logarithmic e sweep mode from F1 to F2 single sweep only from F1 to F2 and back from F2 to F1 single sweep only In this case the total duration of the sweep time is doubled from F1 to F2 continuously sweeping until the Right key is pressed Every sweep from F1 to F2 will have a duration D and the unit will restart at F1 once F2 has been reached O 2006 Jackson Labs J a ck S on FireFox Synthesizer User Manual Labs from F1 to F2 back and forth from F2 to F1 continuously sweeping until the Ri
81. uld cause sparks and thus ignition of flammable gases or fumes 1 3 5 Keep away from Live Circuits Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified service personnel Do not replace components with power cable connected Under certain conditions dangerous voltages may exist even with the power cable 2006 Jackson Labs 3 FireFox Synthesizer User Manual J a ck S on Labs removed To avoid injuries always disconnect power discharge circuits and remove external voltage sources before touching components 1 3 6 Do not Service or Adjust alone Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present 1 3 7 Do not exceed Ratings This instrument is equipped with a line filter to reduce electromagnetic interference and must be connected to a properly grounded receptacle to minimize electric shock hazard Operation at line voltages or frequencies in excess of those stated on the data plate may cause unsafe leakage currents 1 3 8 Do not substitute parts or modify the Instrument Do not install substitute parts or perform any unauthorized modifications to the instrument Return the instrument to Jackson Labs for service and repair to ensure that safety features are maintained Instruments that appear damaged or defective should be made inoperative and secured against unintended operation unti
82. ull modem serial cable Antenna cable offset satellite mask angles timing information satellite health information as wellas GPS vs UTC time base settings are some of the parameters that may be controlled and checked via the PC software overriding the FireFox default settings 3 5 4 can connect to the GPS receiver from my PC but cannot change any settings The FireFox GPS receiver is controlled by its internal microprocessor by default You can monitor all GPS parameters via WinOncore12 but you cannot change its settings in the default mode To change the receiver settings go to MENU SETTINGS COMMUNICATION GPS CONTROL and change the item to REMOTE You must stay in this menu item for as long as you want to change the receiver settings via WinOncore12 Exiting this menu item will return the receiver to LOCAL control and you will again only be able to monitor the receiver parameters without being able to change them 3 5 5 What is the GPS Auto Survey Mode The FireFox system uses a specialized GPS timing receiver Instead of calculating the geographic position this receiver uses a fixed geographic position setting to achieve a very high timing accuracy When the present position is unknown such as when the receiver was moved the satellite receiver will measure and average ten thousand position measurements to achieve a position average with very high accuracy This measurement mode is called Auto Survey Mode The satellite
83. used if GENeration is ANALog In a linear sweep this value is coupled to sweep step by the equation STEP SPAN POINts 1 If POINts are changed STEP will also be changed but not SPAN In a logarithmic sweep POINts will determine the number of points decade of sweep by the equation POINts DECADE POINts 1 SPAN in decades Upon RST this value is set to 2 2 5 2 5 SOURce SWEep TIME lt numeric value AUTO gt This command controls the duration of the frequency sweep when the command INITiate IMMEdiate has been issued This command can be issued at any time during a sweep but it will only be activated after the next trigger event The time unit is in seconds If AUTO is selected the sweep duration is the result of the equation duration POINts 1 DWELI In Hardware Controlled sweeping mode only AUTO can be used Upon RST the default TIME is set to 10 seconds 2 5 2 6 SOURce SWEep STEP This command can only be queried on the FireFox This value is hard coupled to SPAN and POINts by the equation STEP SPAN POINts 1 2 5 2 7 SOURce SWEep GENeration lt ANALog STEPped gt 34 Selects between an analog or stepped sweep STEPped A stepped sweep is selected and the points are controlled by the SWEep POINts and FREQ SPAN ANAL og The sweep is contiguous This is in fact the fastest sweep possible This mode is only supported in Software Controlled sweeping mode Upon RST the sweep GENeration is A
84. ve to do to move the FireFox unit to a different location The FireFox unit is location sensitive due to the GPS receiver operating in location hold mode When factory new the receiver averages ten thousand GPS readings to establish its permanent new location This operation is done only once for every new location or whenever the receiver has been turned off long enough to discharge its internal backup batteries It uses this location as a reference point for receiving the timing solution Establishing a permanent position is called Auto Survey mode and operating with this location data is called position hold mode For the FireFox unit to operate properly and within specification the unit should be placed into Auto Survey mode any time its antenna is moved more than 30 feet 10m This has to be done only once every time the receiver antenna is moved Placing the unit into Auto Survey mode also requires the antenna to have an unobstructed view of the sky for as long as it takes to receive the ten thousand 3D readings that are required to establish the final position data After the receiver has established its permanent position only one GPS satellite is required for synchronizing the internal OCXO thus greatly relaxing the placement requirements of the GPS antenna please note that the receiver requires at least 4 satellites to be operational when the T RAIM timing mode is turned on 44 2006 Jackson Labs J a ck S on FireFox Synthesize
85. version can also be checked in this menu item The GPS status is also displayed in the LCD main frequency setting menu on the right hand side above the SAT and STAT indicator The meaning of these indicators is as follows LCD STAT indicator Meaning OK The unit is receiving at least one Satellite and is locked to better than 15E 011 to UTC AQ The unit is searching for Satellites Acquiring AS The unit is receiving at least 4 Satellites and is in Auto Survey mode 2D 3D The unit is receiving at least 3 to 4 Satellites and Position Hold Mode has been de selected or the unit is entering Auto Survey mode Table 1 1 GPS Status Indicator Abbreviations 2006 Jackson Labs 11 FireFox Synthesizer User Manual J a ck S on Labs LCD STAT indicator Meaning UL The OCXO is not locked to UTC Unlocked BG The unit is receiving sufficient Satellites for Auto Survey mode but the Satellite Geometry is bad and the present Satellites cannot be used Bad Geometry Table 1 1 GPS Status Indicator Abbreviations 1 4 10 3 Sys Config This menu item will show various FireFox system parameters The first item in the LCD is the FireFox Signal Generator Firmware version SCPI commands are available with Firmware Version 3 0 or later The GPS type is displayed The M12 or M12M receivers are used in the FireFox Signal Generator The MTI OCXO version is displayed in this menu
86. w show Uncal OMHz Release the down key and press and hold it again The cursor will now be automatically placed onto the 1KHz digit and down scanning of the frequency will commence at 999KHz A menu item for the upper frequency limit can be set to limit the highest frequency the unit can generate This item is accessible in the SETUP gt OUTPUTS gt FREQ LIMIT menu You may select any frequency as the upper limit in this menu and the unit will then not allow higher frequencies to be selected from the front panel Check the frequency limit setting if you are not able to configure the unit to generate signals up to the 1 64GHz maximum frequency 1 4 5 Setting the RF Amplitude The unit has an analog RF output connector that will provide a sine wave for 50 Ohm terminated loads The RF output is enabled for frequencies from 2MHz to 1640MHz The VALID LED next to the RF OUT BNC connector indicates if the selected frequency is within the range of the RF OUT connector The power level of the output sine wave may be controlled via the front panel keypad The unit has two output level selecting modes e Relative output level ranging from 0 to 100 e Calibrated absolute output level from 40dBm to 10dBm Select the mode in SETUP gt OUTPUT gt POWER UNIT The relative output mode allows the unit to produce its maximum output power which may range from 7dBm to over 18dBm depending on the frequency The absolute output power mode will generate a
87. weeps will affect the LVDS CMOS and RF outputs of the FireFox simultaneously In the Software Controlled sweeping mode the microcontroller controls the frequency of the DDS and changes it incrementally at high speed thereby sweeping the output frequency between the Start and Stop frequencies This mode has the advantage that the RF level of the output is calibrated throughout the sweep Sweeping in software mode is available throughout the entire FireFox frequency range 0Hz to 1640MHz The Hardware Controlled mode uses the DDS circuitry directly by automatically incrementing hardware counters inside the DDS chips This mode allows extremely fast sweeps with frequency update rates of up to 125Mupdates s with a limited frequency range of 2Mhz to 390Mhz The output RF power is not calibrated in HW sweep mode Upon RST the Sweep MODE is set to SW 2 5 2 3 SOURce SWEep DWELI lt numeric value gt This command controls the amount of time in seconds spent at each point during a sweep In Software Controlled sweeping mode this value must be in the range 0 001 1000 with a resolution of 0 001 s 2008 Jackson Labs 33 FireFox Synthesizer User Manual J a ck S on Labs In Hardware Controlled sweeping mode this value must be in the range 8 e 9 5 2428 e 4 with a resolution of 8ns Upon RST this value is 0 001 s 2 5 2 4 SOURce SWEep POINTs lt numeric value gt The number of points in a stepped sweep This parameter is not
88. y references Precise signal synchronization anywhere on the globe is possible due to the units worldwide GPS reception and its synchronization to UTC Test amp measurement applications in production environments Moon bounce type research where signals with low phase noise and extremely high frequency accuracy are required due to the very low level of the reflected RF signal Generating and measuring the effects of Audio Video drift in broadcast applications such as Digital TV distribution IPTV video on demand etc Measuring long term drift and noise on Rubidium Cesium and Crystal Oscillators Measuring performance of RF receivers in the presence of arbitrary jamming signals These jamming signals could be generated with 10uHz resolution and up to 10dbm output power by the FireFox signal generator The output phase can be controlled in 0 1 degree steps from 180 to 180 degrees allowing very precise alignment of signals for quadrature type applications The frequency the amplitude and most other internal settings can be controlled via an RS 232 serial port under host PC control allowing automated test setups SCPI compatible RS 232 control firmware upgrade available Q2 2006 1 6 2 Signal Generator Outputs The following output signals are available on the FireFox unit CMOS OUTPUT 3 3 Vpp or 5Vpp user selectable via back panel switch A best in class extremely high speed generic CMOS compatible output

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