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AFG-3000 Series User Manual

1. MHz MHz 66 GW INSTEK RF Communication and Signals Experiments 878MHz MHz MHz Conclusion Questions 1 If we change the frequency of the modulating wave but keep the amplitude the same will the AM wave be affected 2 If the input cables on the AM modules were switched Connect the baseband signal to the RF in terminal and connect the carrier signal to the AM in terminal what will happen and why 67 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment 6 FM signal measurement Relevant Since frequency modulation is a common type of modulation information it is important to learn the principles and characteristics of FM Experiment equipment Experiment goals Experiment principles 68 waves Compared to AM waves the amplitude of an FM wave doesn t carry the modulating signal information This allows an amplitude limiter to be used to eliminate the magnitude interference before demodulation The noise power spectral density in an FM wave band is evenly distributed at the input terminal But due to frequency modulation it is affected by frequency at the output terminal Because the bandwidth of a modulated signal is far less than the FM wave bandwidth it can pass through a low pass filter to attenuate noise and increase the output signal to noise ratio during demodulation FM waveforms are advantageous as they utilize power efficiently and have a high degree of fidelity as
2. Start 875 0MHz Center 880 0MHz Stop 885 0MHz RBW 100kHz Span 10 0MHz 5 Measure the ACPR and OCBW after these settings are performed Step1 Fees Tey os GWINSTEK RF Communication and Signals Experiments OCBW measurement Experiment results step OR Set the bandwidth of the main channel to 2MHz sep ORT Set the main channel space to 5MHz Step4 o e El Set the bandwidth of the 1st adjacent channel 0 8MHz steps Set the offset of the 1st adjacent channel to 2MHz steps Kl Set the bandwidth of the 274 adjacent channel to 0 5MHz step7 OR Set the offset of the 2 4 adjacent channel to 4MHz Increase the frequency deviation to 2MHz 4MHz in total using the amplitude knob Measure the ACPR again and record the results to table 7 1 Step1 cD ka step tal Set the bandwidth of the channel that you will measure to 2MHz step a Set the span of the main channel space to 1OMHz Step4 The OCBW is default at 90 Record the measurement data in Table 7 2 Step5 Adjust the frequency deviation of FM wave by adjusting the potentiometer of GRF 1300 Measure the OCBW again and record the results to table 7 2 Record the measurement data in Table 7 2 1 ACPR measurement results 83 GW INSTEK GRF 1300 User Manual and Teaching Materials IMHz frequency 40 deviation results dB r MHz MHz 2MHz frequency 40 deviation results dB p MHz MHz Table 7 1 A
3. COS Wc Q t We can see when mp lt lt 1 the FM wave spectrum is composed of the carrier Q frequency component and Q frequency component When my gt gt 1 cos mr sin Qt Jo mr 2 J2 mr cos 2Qt 2 7 4 my cos 4Qt sin ny sin Qt 2 i my sin Qt 2 3 m7y cos 30 2 s my sin SOY In this formula J m is called an n order Bessel function of the first kind There are an infinite number of frequency components in FM waves and they are distributed symmetrically around the center of GW INSTEK RF Communication and Signals Experiments carrier frequency The amplitude of each component depends on the Bessel functions Theoretically FM bandwidth is infinite but the energy of an FM signal is mainly concentrated near the carrier frequency The sidebands of the FM signal only contain a small amplitude component and are generally ignored in practice by engineers Provided that the amplitude at the sidebands is negligible less than 10 we can get the FM wave band as follows B 2 my 1 F From above analysis m A m _ AF Because 1 Q F Therefore B 2 AF F When AF gt gt F it is wide band modulation my gt gt 1 B 2AF When A F lt lt F it is narrow band modulation mf lt lt lBw22F The amplitude of the sideband components in an FM signal is related to the frequency modulation index This can be seen in the comparison table in the appendix Below we have a few examp
4. The distribution of these harmonic components can be clearly seen in the frequency domain Frequency domain analysis describes the characteristics of a signal from another viewpoint GYVINSTEK Time domain ANS SS Overview of the Time and Frequency Domain Lo DA Frequency domain 17 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 18 GYVINnSTEK Overview of the Time and Frequency Domain NOTES 19 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 20 GW INSTEK Overview of the Time and Frequency Domain NOTES 21 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 22 GW INSTEK An Introduction to Spectrum Analyzers AN INTRODUCTION to SPECTRUM ANALYZERS Spectrum analyzers are one of the most important instruments for RF microwave measurements Being familiar with spectrum analyzers in general is very important for operating high frequency microwave equipment or for performing communication measurements In addition being familiar with the basic operating principals will allow you to quickly understand other related test equipment In this chapter we will briefly introduce the basic working principles of the spectrum analyzer After understanding the basic working principles you will find that a spectrum analyzer can be a handy tool to use Broadband Receiver The principal function of a spectrum analyzer is to convert the input signal frequency d
5. hazardous If a cable or plug is deemed hazardous turn off the mains power and remove the cable any fuses and fuse assemblies All hazardous wiring must be immediately destroyed and replaced in accordance to the above standard GYVINSTEK About this Book Asout THIS BOOK This textbook was developed in conjunction with the GRF 1300 RF amp Communication Trainer and the GSP 730 3GHz spectrum analyzer as an RF communications education system It not only offers detailed examples but also the practical knowledge necessary for RF measurements such as spectrum analyzer principals as well as AM and FM communication systems For you to easily understand the contents of this textbook we have included as many pictures and diagrams as possible to strengthen your comprehension This book is divided into a teacher version and two student versions All experiment results are included in the teacher edition In addition chapters with an asterisk indicate additional text for advanced reading not present in the student addition Students will not be affected by the omission of the additional text To further help students the student edition will contain a Notes section in these missing areas GWINSTEK GRF 1300 User Manual and Teaching Materials NTRODUCTION to the GRF 1300 The GRF 1300 is a well designed training kit capable of producing a 3MHz baseband signal and a carrier signal up to 900MHz The GRF 1300 is also able to perform
6. sep GID o El steps Bo EE Below the display you can set the magnitude and frequency of each point Move the cursor to select a point and edit it with the number pad and unit keys Press Fe to return to the previous menu step7 OBA According to the procedures above students can set the limit lines Adjust the amplitude knob on the GRF 1300 Observe the Pass Fail test results and record the results to table 9 1 The same functionality can be achieved by sending remote commands from a PC using HyperTerminal Table 9 1 Results for adjusting the position of the amplitude knob 5MHz frequency deviation test results 92 10 MHz MHz GYVINSTEK RF Communication and Signals Experiments 10MHz frequency 40 deviation test dB results MHz 93 GW INSTEK GRF 1300 User Manual and Teaching Materials Test for LEARNING OUTCOMES Experiment Aim Experiment Contents In the previous experiments we introduced the concepts behind phase locked loops amplitude modulation and frequency modulation and we now have a good understanding of them But that is not enough to fully grasp RF circuits This experiment combines these three parts to form one system Each module in the circuit can be turned on or off via remote commands so that the experiments can be used to diagnose simulated malfunctions When students analyze the causes of these malfunctions they will have an overall underst
7. 25 0 11 0 20 0 01 0 03 0 06 0 07 0 13 0 26 0 39 0 40 0 36 0 16 0 02 0 02 0 04 0 13 0 26 0 32 0 36 0 35 0 19 0 03 Sideband 6 0 01 0 01 0 05 0 13 0 79 0 25 0 34 0 34 0 26 0 20 T 8 9 10 11 12 13 14 15 16 0 02 0 05 0 02 0 09 0 03 0 01 0 13 0 06 0 02 0 23 0 13 0 06 0 02 0 327 0 22 0 13 0 06 0 03 0 34 0 26 0 16 0 10 0 05 0 02 0 33 0 31 0 21 0 12 0 06 0 03 0 07 0 27 0 32 0 29 0 21 0 12 0 06 0 03 0 01 0 18 0 07 0 24 0 17 0 05 0 23 0 30 0 27 0 20 0 12 0 07 0 03 0 01 107 GW INSTEK GRF 1300 User Manual and Teaching Materials Declaration of Conformity We GOOD WILL INSTRUMENT CO LTD No 7 1 Jhongsing Rd Tucheng Dist New Taipei City 236 Taiwan GOOD WILL INSTRUMENT SUZHOU CO LTD No 69 Lushan Road Suzhou City Xin Qu Jiangsu Sheng China declare that the below mentioned product Type of Product RF amp Communication Trainer Model Number GRF 1300 are herewith confirmed to comply with the requirements set out in the Council Directive on the Approximation of the Law of Member States relating to Electromagnetic Compatibility 2004 108 EEC and Low Voltage Directive 2006 95 EEC For the evaluation regarding the Electromagnetic Compatibility and Low Voltage Directive the following standards were applied Electrical equipment for measurement control and laboratory use EMC requirements 2006 Conducted amp
8. As the oscillator is a non linear component it will produce higher harmonic content Harmonic distortion is also an important factor for RF signals In general we use a filter to filter this out 47 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment contents Experiment steps Measure the RF signal spectrum and harmonic distortion 48 1 1 Measure the RF signal spectrum Measure the harmonic distortion of the RF signal Measure the phase noise of the RF signal Turn on the GRF 1300 and GSP 730 Leave the GRF 1300 in its power on state Connect the RF FM output port on the GRF 1300 to the input terminal on GSP 730 with the RF cable Set the GSP 730 as follows e Span Full Span e Reference level 0dBm e RBW Auto Auto Step1 ep a tp GDoo Ell sp o On the observed spectrum use the marker function to measure the amplitude of each frequency point The Next peak function can be used to find each consecutive peak Plot the results in table 4 1 Peak otep4 Peak Steps GS AO Draw the results in table 4 1 The harmonic ratio of each the harmonic can be measured according to the following steps Step6 CD ES OOOO Step7 GD ES DOODO GWINSTEK RF Communication and Signals Experiments Measure the RF phase noise For the last two steps the span is quite large and may produce some errors To find the second and third harmonic you may need to fine tune the
9. Returns the state open or closed of the number for the currently selected relay corresponding test WAVE 0 WAVE 1 WAVE 2 et the waveform to square Bn 0 n is the relay Set the relay of corresponding no to OFF oo I e B1 0 en L ey B3 1 frequency E 14 GW INSTEK Overview of the Time and Frequency Domain Overview of the TIME and FREQUENCY DOMAIN Observation from a different perspective When a signal is said to be in the time domain it means that the signal is expressed as a function of time For example if we describe a sine wave signal that repeats once each microsecond psec 10 it means that the period of the signal is 1 microsecond Usually we use an oscilloscope to measure these signal characteristics in the time domain In addition when we talk about the rise and fall time of a square waveform we also can observe that in the time domain Phase delay is also measured in the time domain Oscilloscopes are well known electrical signal measurement instruments that perform measurements in the time domain GY STEER wa 0 000s Trigd Measure aH INSTEE wo A Gas Trigd jL _ Measure E oa a a e re ee rere hee a ee er ae tae mE eg ee eoe a ee eg re err rs Period Po O oo d Feriad i 1 686us ee D E A G EE E 2 chan of t J2 chan off l f i s l Aree z en TETEE eea Vavg Saa paaa ee oe lt i Calne ee eames VWavg F L T 71 35 aml Eo ee ee ee e
10. and contact the hardware vendor for software that has passed Windows Logo testing STOP Installation e Next click on the Continue Anyway button to continue the installation until the installation procedure is complete Figure A 9 Found New Hardware Wizard Installation l procedure is Completing the Found New complete Hardware Wizard The wizard has finished installing the software for F USE Communications Port ii Click Finish to close the wizard z Back Finish Cancel e After the software installation is complete users can perform a system error check by sending commands to the GRF 1300 using Hyper Terminal 12 GW INSTEK Introduction to the GRF 1300 Figure A 10 Operation interface for HyperTerminal uy New Connection Enter a name and choose an icon for the connection Connection Description Mame E lor gg HyperTerminal File Edit View Call Transfer Help IDN GW INSTEK GRF 1300 SN Connected 0 01 27 Auto detect 9600 8 H 1 13 GW INSTEK GRF 1300 User Manual and Teaching Materials 9 Below is a table listing each instruction and a description of each function Instruction Function IDN Returns the manufacturer model name and serial number RF Returns the value on the digital display of the FM RF module Returns the value on the digital display on baseband module WAVE Returns the waveform type on the baseband module Bn n is the relay
11. frequency Record the results in table 4 2 1 Turn on the GRF 1300 and the GSP 730 2 Set the GRF 1300 RF Synthesizer FM as follows e Carrier frequency 875MHz step J gt ETE DOWN 3 Connect the RF FM output port on the GRF 1300 to the input terminal on GSP 730 with the RF cable 4 Set the GSP 730 as follows e Center frequency 875MHz e Span MHz e Reference level 0dBm e RBW Auto default state is 50kHz sp GDecoe Ea sp Doo Ea sp GDeoo 2 Step4 ew Tay Steps 5 Record the carrier power Set the deviation of the carrier frequency fm to a deviation of 100kHz Use the Delta marker function on the spectrum analyzer to measure the A value sep BoM ooo D 49 GW INSTEK GRF 1300 User Manual and Teaching Materials Record the value then calculate the phase noise according to the formula and record the spectrum and measurement results in Table 4 3 6 Adjust the PLL output frequency to 900MHz and again measure the power and phase noise corresponding to the frequency Step7 J gt 9688 UP sp DOO ce El Peak step9 Record the carrier power Set the deviation carrier frequency fn to a deviation of 100kHz Use the Delta Marker function on the spectrum analyzer to measure the A value sep G DeBooos Record the value then calculate the phase noise according to the formula and record the spectrum and measurement results in Table 4 3 7 Adjust the PLL output frequenc
12. on more important parameters such as phase noise and harmonic distortion A Phase locked loop PLL is a phase error control system It compares the phase between a reference signal and an output signal to generate a phase error voltage for adjusting the frequency output of the voltage controlled oscillator for the purpose of synchronizing the output frequency with the reference signal Its basic circuit structure is shown in Figure 4 1 GW INnSTEK RF Communication and Signals Experiments Figure 4 1 PLL circuit structure Figure 4 2 Phase noise definition UO UO UM UO Above PD is the phase locked loop phase detector LF is the loop filter and VCO stands for voltage controlled oscillator The purity of the output signal from the VCO is directly related to the phase noise The lower the distortion of the output signal the lower the harmonic components and noise contained in the output signal Phase noise is usually specified in dBc Hz at a given frequency offset value where dBc is dB in relation to the center frequency The phase noise of an oscillator is normalized to the noise generated in a bandwidth of 1Hz The phase noise is usually calculated using the formula below where fm is the frequency of a single sideband from the carrier and P ssg is the measured sideband power L fn Pssp Po log B 2 5 where B 1 2RBW RBW is the resolution bandwidth Po ssB Ja
13. the keypad to control the frequency amplitude and other related settings The Frequency Amplitude and Span keys as well as the keypad and unit keys There are two ways to set the frequency If the frequency of the signal that you want to measure is known then we can set the frequency using the center frequency and span functions If we need to measure a frequency range then we can set the start and stop frequency range Experiment Connect the antenna to the GSP 730 spectrum analyzer to contents test the radio waves in the environment Experiment 1 Connect the antenna to the GSP 730 spectrum analyzer steps Measure the strength of a mobile phone s transmitter signal Because the frequency band of a mobile phone is between S800MHz 1900MHz we will set the frequency range between 800 1900MHz 2 Set the GSP 730 as follows e Start frequency 800MHz e Stop frequency 1900MHz e Reference level 30dBm e RBW RBW Auto sp ZED eooo Ea sep ID eooe Ei 32 GW INSTEK RF Communication and Signals Experiments tp G Deaooo Ea se GD o ISS 3 Now we should see some signals on the spectrum analyzer screen Identify the three highest peaks and write down their frequency values The reference level can be used to adjust the strength of the signal 4 As mobile phones use frequency hopping we can use the Peak Hold function to hold the reading of the signal on the display screen Record the frequency and amp
14. the output amplitude of the modulating signal can you observe any change in the spectrum Record the experiment in Table 5 4 Step1 Step2 Step3 7 Turn the potentiometer counterclockwise to decrease the output voltage Measure the voltage with the oscilloscope Observe any changes in the spectrum of the AM wave and record it in Table 5 4 GW INSTEK RF Communication and Signals Experiments 8 Turn the potentiometer clockwise to the maximum Adjust the UP button on the Baseband module to adjust the frequency of modulating signal Do you see any change in the AM wave spectrum Compare the experiment results with that of the original baseband frequency of 100kHz and record it to Table 5 5 Stp7 TAN 7 gt N gt kHz seps oM ooo 9 Use the UP button on the Baseband module to adjust the frequency of the modulating signal Do you see any change in the AM wave spectrum Record the result in Table 5 5 Step9 i rai o 19 gt Ha gt Step10 GD OOO usec 10 After completing the experiment steps above press the Reset button and then use the UP button on the RF Synthesizer FM module to change the frequency of the carrier signal Is there is any change in the AM wave spectrum Compare the experiment result with that of the original carrier frequency of 880MHz and record it to Table 5 6 Step11 O Reset Step12 2 Fl Step13 sepu DoM ooo o 11 Use the DOWN button on the RF Synthesiz
15. the transmitter leaks into the transmission band of other channels The adjacent channel usually refers to the closest adjacent channels near the transmission channel other channels can also be selected depending on the measurement requirements When two signals with similar frequencies are input into an RF power amplifier there are not only two output signals but also the inter modulation signals input signal 1 input signal 2 A typical input and output frequency spectrum is shown in Figure 7 1 Power level Output signal fo 3B fo B fo fotB fo 3B Frequency Power level pcarrier fo 3B fo B fo fo B fo 3BFrequency GW INSTEK RF Communication and Signals Experiments Experiment contents Experiment steps In accordance with the definition of ACPR Figure 7 2 we know that ACPR 10 log Padi Pcarrier When using a spectrum analyzer to measure ACPR first you need to select the appropriate settings for the span and the resolution bandwidth RBW The span needs to be greater than the measurement bandwidth The RBW should be equal to approximately 1 of the measurement bandwidth Because the sweep time of the spectrum analyzer is inversely proportional to the square of the RBW the RBW settings should be considered The RBW should not more than 4 of the measured channel bandwidth Otherwise the RBW will too wide and will obscure the original spectrum of channel The RBW settings on the GSP 730 ha
16. to the RF input port on the spectrum analyzer with an RF cable Iesele l eG el e 000 000 D waw i ooo i i t r 3 Set the GSP 730 as follows e Center frequency 880MHz e Span SOMHz e Reference level 0dBm e RBW Auto 72 GWINSTEK RF Communication and Signals Experiments sep QDAOOo El Step2 peooo Step3 GDeoo El Step4 Qo 4 Ea Use the Marker function on the spectrum analyzer and measure the carrier position at this time Peak Step5 Turn the potentiometer clockwise to an arbitrary position Measure the voltage with an oscilloscope Does the FM wave spectrum change after the output amplitude of the modulating signal has changed Follow the steps below to measure the frequency deviation and record it in Table 6 2 Step6 cD EO 6 Turn the potentiometer clockwise again to a different position Measure the voltage with an oscilloscope Does the spectrum of the FM wave change when the output amplitude of modulating signal changes Follow the steps below to measure the frequency deviation and record it in Table 6 2 Step7 2 7 Adjust the potentiometer to the maximum position Repeat the above steps and record the results in Table 6 2 steps 2 8 After the completing the experiment steps above see if there is any change to the spectrum of the FM wave when the UP button on the baseband module is used to change the frequency of the modulating sign
17. 0000 CD Ea When the first step is done steps 2 and 3 below will have already been automatically set Students may do steps 2 and 3 here is for reference only sp QDeo El sp GDeol El tpt GDooo 2 Ea Step5 GD JO 5 Utilize the Marker function on the spectrum analyzer to determine the harmonic ratio and draw the spectrum in Table 2 1 Peak step6 36 GW INSTEK RF Communication and Signals Experiments Experiment results After step 6 is done make sure the Delta marker is used for the next steps and not the Normal marker Set the Delta Marker to the peak point of each harmonic and make a record by drawing a simple sketch of the spectrum in table 2 1 sep oM stepe GDeBme 6 A function signal generator can also be used as a signal source in the above measurement but be aware that the amplitude of the output signal can t be too high dBm is a power unit that is referenced to ImW The formula for X dBm 10 log Px 1mW Putting 10 mW into the above formula we get 10 log 10 1 10 1 10dBm Similarly if we input 100 mW into the above formula X 10 log 100mW 1mW 10 2 20dBm Because the output voltage of a signal generator is often used expressed as a voltage into a 50 ohm load you must convert voltage to power A few common values are listed below Converting Voltage to dBm into 50 ohm load 10 00 10 00 Converting dBm to Voltage into 50 ohm load P mW Vrms V Vm V
18. AM and FM RF circuit experiments as well The practical exercises in the training kit meet the needs of most general RF courses The GRF 1300 consists of three modules namely a baseband module an RF Synthesizer FM module and an AM module The baseband module can simulate a baseband signal and includes sine square or triangle waveforms Its output frequency and amplitude are adjustable During experiments the three kinds of waveforms can be arbitrarily switched back and forth to meet the signaling requirements of each of the different experiments The RF Synthesizer FM module is used to generate an adjustable carrier frequency as well as perform frequency modulation This module covers some of the focus points in the RF circuit theory This will be highlighted in practical experiments in later chapters FM waveforms can also be produced by using this module together with the baseband module The GSP 730 spectrum analyzer can be used to observe the various characteristics of an FM waveform The AM module and baseband module can be used together to perform amplitude modulation experiments The GSP 730 Spectrum Analyzer can be used to observe the various characteristics of an AM waveform This experiment system can be connected to a computer via the USB interface The interface can be used to turn individual circuits on or off so that students can perform diagnostic experiments Students can learn the fundamental aspects of RF theory throug
19. CPR measurement results Item 2 OCBW measurement results 84 GW INSTEK RF Communication and Signals Experiments 1MHz frequency deviation results dB i 2MHz frequency deviation results dB r Questions Caution 10 MHz MHz 10 MHz MHz Table 7 2 OCBW measurement results OCBW OCBW a ee ee el ee ee al o ee ee a ee ps Describe the definition for ACPR Taking multiple measurements and the getting average value is required for ACPR and OCBW measurements Using the Average function cannot be used as it uses a logarithmic method to calculate the average 85 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment 8 Measurement of communication products Relevant information Experiment equipment Experiment goals 86 The computer mouse has experienced nearly four decades of evolution and development since its inception in 1968 With the popularity of consumer oriented computers over the past decade the mouse has seen tremendous progress From the early mechanical wheel mouse to the current mainstream optical mouse or the high end laser mouse each evolution of the mouse has been more enjoyable to use each time In addition the demand for better work environments has made the wireless mouse very popular Wireless technology depending on the frequency band and its purpose is divided into different categories such as Bluetooth Wi Fi IEEE 802 11 Infrared Ir
20. Cleaning the GRF 1300 Operation environment Storage environment Measurement categories EN 61010 1 2010 specifies the measurement categories and their requirements as follows The device falls under category I Measurement category IV is for measurement performed at the source of a low voltage installation Measurement category III is for measurement performed in a building installation Measurement category Il is for measurement performed on circuits directly connected to a low voltage installation Measurement category is for measurements performed on circuits not directly connected to Mains AC Input voltage 100 240V AC 50 60Hz Connect the protective grounding conductor of the AC power cord to an earth ground to prevent electric shock Fuse type 1A 250V Only qualified technicians should replace the fuse To ensure fire protection replace the fuse only with the specified type and rating Disconnect the power cord and all test leads before replacing the fuse Make sure the cause of the fuse blowout is fixed before replacing the fuse Disconnect the power cord before cleaning the device Use a soft cloth dampened in a solution of mild detergent and water Do not spray any liquid into the device Do not use chemicals containing harsh products such as benzene toluene xylene and acetone Location Indoor no direct sunlight dust free almost non conductive pollution Note below and avoid strong
21. DA ZigBee IEEE 802 15 4 and so on But for the current mainstream wireless mouse there are three different categories 27Mhz 2 4G and Bluetooth This experiment actually performs measurements on actual communication products a wireless mouse in this case After performing this experiment you should have a good understanding of the spectrum analyzer and the measurement methods used This experiment will help to consolidate your RF knowledge and to strengthen your practical spectrum analyzer skills iter Quantity _ Note 1 Spectrum analyzer 1 GSP 730 Adapter 1 NSMA 1 Use the spectrum analyzer to measure some parameters from common every day electronic communication products H G2 NO 2 Learn how a wireless mouse works GW INnSTEK RF Communication and Signals Experiments Experiment principles Experiment contents Experiment steps In this experiment we will use a 2 4G wireless mouse It uses the so called 2 4G frequency band The advantage of the 2 4G band over the 27MHz band is that the 27MHz band has a shorter transmission distance and is prone to interference from other devices We call it 2 4G because it operates in the 2 4GHz frequency band In most countries this frequency band is license free The principle of the wireless mouse is actually very simple It mainly uses digital radio technology to provide adequate bandwidth for communications equipment over a short distance It is ideal for peripheral equi
22. RF amp Communication Trainer GRF 1300 STUDENT BOOK USER MANUAL and TEXT BOOK GW INSTEK PART NO 82RF 13000MA1 ISO 9001 CERTIFIED MANUFACTURER x DY INSTEK This manual contains proprietary information which is protected by copyright All rights are reserved No part of this manual may be photocopied reproduced or translated to another language without prior written consent of Good Will Corporation The information in this manual was correct at the time of printing However Good Will continues to improve its products and therefore reserves the right to change the specifications equipment and maintenance procedures at any time without notice Good Will Instrument Co Ltd No 7 1 Jhongsing Rd Tucheng Dist New Taipei City 236 Taiwan GW INSTEK Table of Contents Table of Contents SAFETY INSTRUCTION Cee ener ee ee ee 2 ABOUT TES BOOK meneren a E E E E EEE E 5 INTRODUCTION to the GRF 1300 ccccsscessceeseneeees 6 CICS COMENTS nean E oacaesesceseciaessceeutasecdcmenacennccamagee aeneneanes 8 Product Specifications and FUNCTION xccsescterrscensteneidceeenieupedeccousnudeiciaiccamensests 8 WS ae TAS TOC HON S eee a E T E E 9 OVERVIEW of the TIME and FREQUENCY DOMAIN 15 Observation from a different perspective cccceccceccescceeeeeeeeeeeeeeeeeeeeeeeeeeees 15 AN INTRODUCTION to SPECTRUM ANALYZERS 23 Brocaband ReCO arrear e A E E E ET 23 PST A OM E E E E E E E E cae 24 RESON OM B
23. Radiated ClassB Electrostatic Discharge Emission IEC 61000 4 2 2008 EN 55011 2009 A1 2010 EN 61000 3 2 2006 A2 2009 IEC 61000 4 3 2006 A2 2010 Voltage Fluctuations Electrical Fast Transients EN 61000 3 3 2008 IEC 61000 4 4 2004 A1 2010 surge Immunity IEC 61000 4 5 2005 ec ee IEC 61000 4 6 2008 ec ee IEC 61000 4 8 2009 EE iwm IEC 61000 4 11 2004 Low Voltage Equipment Directive 2006 95 TEC Safety Requirements IEC 61010 1 2010 Third Edition 108
24. Vpp V 20 00 100 00 10 00 10 00 000 100 022 032 f 063 10 00 If voltage is measured without a load on an oscilloscope the Vpp and Vm values should be multiplied by 2 For instance when we get a measured value of 4Vpp into no load it is the equivalent of 2Vpp into 50 ohms or 10dBm after conversion 37 GW INSTEK GRF 1300 User Manual and Teaching Materials Question Caution 33 Mhz MHz nm cn amp 4s MHz MHz The 3 harmonic ratio is Table 2 1 MHz sine wave spectrum test results 1 What is the spectrum of a theoretical sine wave and why is it different with the actual measured one 2 What is the frequency domain feature of the analyzed signal 1 The output power should not exceed the rated input of the spectrum analyzer otherwise the spectrum analyzer will be damaged 2 When using the RF cable to make a connection be sure to tighten the connector GW INSTEK RF Communication and Signals Experiments Experiment 3 Different Baseband Waveforms and their Harmonic Measurement Relevant information Experiment equipment Experiment goals You should already be familiar with electrical signals in general We have already said that an oscilloscope is used to observe the amplitude of a waveform In other words it is used to observe how an electrical signal X t varies over time However depending on what we are trying to study the reason for measurin
25. al Compare this to the original 100kHz baseband signal and record it to Table 6 3 S o a On 9 N J Change the modulating signal frequency to 600KHz Observe the change in the spectrum of the FM wave and record the results in Table 6 3 73 74 GW INSTEK GRF 1300 User Manual and Teaching Materials Step10 eo ee AOE UP ON N mL 10 Change the modulating signal frequency to 1MHz Observe the change in the spectrum of the FM wave and record the results in Table 6 3 Step11 2 R 11 After the completing the experiment steps above press the Reset button and minimize the amplitude of the modulating signal in order to view the FM spectrum within a span of 50MHz Then use the DOWN button on the RF Synthesizer FM module to change the frequency of the carrier signal See if there is any change in FM wave spectrum Compare this result to the original carrier frequency of 880MHz and record it in Table 6 4 l Step12 Amp Adj steps FEET DOWN 12 Adjust the carrier frequency again See if there is any change on FM wave spectrum and record it to Table 6 4 St u au jO EE GW INnSTEK RF Communication and Signals Experiments Experiment 1 Changing the amplitude of the modulating signal results Table 6 2 Modulatin Experiment result perimental voltage amare Von the modulating signal MHz MHz Frequency deviation FM index Vpp Mkz MHz Frequency deviat
26. allows students to comprehensively understand how to operate a spectrum analyzer and lays the foundation for subsequent experimente tem Quanity Nois 1 ST Spectrum analyzer 1 GSP 730 RF amp Communication a CRE 1300 oe 800mm 1 NSMA 1 Measurement and analysis on a basic signal Aow N 2 To understand how to use the GRF 1300 system to output a baseband signal Set the GRF 1300 to output a 1MHz sine waveform and use the GSP 730 to measure its spectrum The working principle of a spectrum analyzer has been introduced in a previous chapter We won t repeat it here Set and then measure the spectrum of a 1MHz sine wave Measure the harmonic ratio at each of the harmonic frequencies 1 Turn on the GRF 1300 and the GSP 730 2 Set the GRF 1300 baseband as follows e Waveform Sine wave e Frequency 1MHz e Turn the amplitude knob clockwise to its end so lo gt X 3 em Wave Select 35 GW INSTEK GRF 1300 User Manual and Teaching Materials 8 ON e g HE UP Step3 G Amp Adj Connect the baseband signal from the output port of the GRF 1300 to the input terminal of the GSP 730 using the RF wire i ey d mir 0000 CE p 029 lesso 0000 0000 000G 9gag OOOO ooog Vt f ooo a H T 4 Set the GSP 730 as follows e Center frequency 2 5MHz e Start frequency 0kHz e Stop frequency 5MHz e Reference level 10dBm e RBW Auto sep D
27. an WI Gtlt PIECE areena A E NE 24 RF COMMUNICATION and SIGNALS EXPERIMENTS 30 Experiment 1 Basic Operation of a Spectrum AnalyZer cccceecceeeeneeeeeees 3 Experiment 2 Measuring a Baseband Waveform c ccsccceecceeeceeeceeeeeeeeeeens 35 Experiment 3 Different Baseband Waveforms and their Harmonic WAS UG E a fe sdepe seed E E A E ee one ase E ens 39 Experiment 4 Measurement of the RF Carrier cccccccceccneccneeeeeeeeneeeeeeenees 46 Experiment 5 AM Signal Measurement cccscssccesccsecescesscescesccesensccesenes 58 Experiment 6 FM signal MEASUPEMOENT is ccasewscauctadaneeagercseneacdsaesdenineaneenntunsds 68 Experiment 7 Using a Spectrum Analyzer in Communication Systems 19 Experiment 8 Measurement of communication Products cccceeeeeeeeeeees 86 Experiment 9 Production Line Applications ccccceccsecceccecceeeeeesseeeeeeeeeees 89 TEST for LEARNING OUTCOMES ccsecccsecceeecesseeees 94 APPENDIX conrra E E EA E E 103 CETE CONVEN TID Goe a E E EE 103 The relationship between dB and ABC ccccceecneccecceeceeceeseeseecescescceeness 103 Resistor Values in n type Resistance Attenuators ssssssssessessrsessrseserseeses 105 Resistor Values in T type Resistance Attenuators s sssssssessessrsessrserseseeses 106 Modulation Index and Sideband Amplitude Comparison Table 107 Declaration of Conformity s sssessssessesserserserserserserse
28. and is proportional to the modulating signal Therefore the information in a modulating signal is carried in the amplitude of an amplitude modulated wave The following figure shows how a signal changes from a carrier signal 59 GW INSTEK GRF 1300 User Manual and Teaching Materials unmodulated state to an AM wave modulated state Figure 5 1 A diagram showing how an unmodulated carrier signal undergoes the process of modulation Figure 5 2 AM waveform in the time domain and the frequency domain Ue m Uam t 2 AM Wave Spectrum Expand formula 4 3 to get the following formula l l Uan t Ucm COS Oct poe COS We Q t Ps COS We Q t As can be seen here a single modulated audio signal consists of three high frequency components In addition to the carrier two new frequency components Q and Q are included One is higher than Oc known as the upper sideband and the other is lower than known as the lower sideband Its spectrum is shown in Figure 5 3 60 GW INnSTEK RF Communication and Signals Experiments Figure 5 3 Spectrum of an AM wave Q We WetQ Frequency From the above analysis we can understand that amplitude modulation is a process of shifting a low frequency modulating signal into the sideband of a high frequency carrier Obviously in AM waves the carrier does not contain any useful information Information is only included in the sidebands Experi
29. and square waves O MHz O MHz GW INnSTEK RF Communication and Signals Experiments Table 3 2 A t Time domain waveform of the 1MHz triangle wave Table 3 3 1MHz square wave spectrum test results MHz MHz Table 3 4 A t Time domain waveform of the 1MHz square wave t 43 GW INSTEK GRF 1300 User Manual and Teaching Materials 2 For the triangle waveform measure the harmonic ratio of the 3rd and 5th harmonic For the square waveform measure the harmonic ratio of the 2 4 and 3 harmonic Harmonic ratio of the 3rd harmonic gg triangle wave MHz MHz Harmonic ratio of the 5th harmonic dB triangle wave MHz MHz GW INnSTEK RF Communication and Signals Experiments Harmonic ratio of 10 the 2 harmonic dB Square wave 0 MHz MHz Harmonic ratio of the 3 harmonic dB Square wave MHz MEZ Question 1 Compare the measurement results from the frequency domain and the time domain and consider the relationship to the Fourier series theory 2 Analyze the difference between the triangle and square wave spectrum Write their Fourier series in the form of a trigonometric function What relationship do you find between each harmonic and each term in the series Caution There are different ways to set the center frequency ona spectrum analyzer Set it according to your needs 45 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment 4 Meas
30. anding about the relationship and principles behind each one This helps students build their knowledge of PLLs AM and FM 1 Understand how and why a phase locked loop enters the lock state or loses the lock state 2 Have an understanding of the overall communication system The instructor will send remote commands to the GRF 1300 and create a malfunction Students can use an oscilloscope spectrum analyzer and or other measurement instruments to try to deduce verify the cause of the malfunction fault 1 RF signal Fault Simulation Fault 1 Fault description Hypothesis Verification 94 GYVINSTEK Fault 2 Fault description Hypothesis Verification 2 FM Fault Simulation Fault 1 Fault description Hypothesis Verification Fault 2 Test for Learning Outcomes 95 GWINSTEK GRF 1300 User Manual and Teaching Materials Fault description Hypothesis Verification Fault 3 Fault description Hypothesis Verification Fault 4 Fault description Hypothesis 96 GW INSTEK Test for Learning Outcomes Verification 3 AM Fault Simulation Fault 1 Fault description Hypothesis Verification Fault 2 Fault description Hypothesis Verification 97 GWINSTEK GRF 1300 User Manual and Teaching Materials Fault 3 Fault description Hypothesis Verification Fault 4 Fault description Hypothesis Verification 98 GYVIN
31. awing a simple sketch of the spectrum in table 3 1 step oA o C 6 step oo C 7 6 Select the square wave on the GRF 1300 Baseband module Do the same spectrum measurements that were performed in the previous steps eo oO _ sips J MEE X Wave Select 7 Observe the square wave spectrum that appears on the spectrum analyzer Use the marker function to record the harmonic ratio and draw the spectrum in table 3 3 Draw the spectrum of the square wave spectrum as you did previously for the triangle wave Remember to remove the delta marker A Marker that was originally used with the triangle wave Step9 GD Es After the spectrogram on table 3 3 is drawn measure the 41 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment results Table 3 1 1MHz triangle wave spectrum test results 42 harmonic ratio of each harmonic using the following steps stepo Damo stp GDefme In accordance to the method that is used above to measure the harmonic ratio students can try to measure the harmonic ratio of the higher order harmonics After measuring the spectrum connect the output port to the input port of the oscilloscope and measure the time domain waveform of the triangle wave and square wave and record the results in Table 3 2 and Table 3 4 In the tables below record the measurement results of the time domain waveforms and the frequency domain spectrum for both the triangle
32. e Editing Table shown below Lower Limit Line Editing Table MHz dBm No MHz dBm on 4 4 44 4 J 4 Seg go go tt Be He ee sxe O OGG EE k1 u S OGG O O OGA re M O Ps O OGG m m 89 GV INSTEK gO GRF 1300 User Manual and Teaching Materials Set the amplitude and frequency of each point Use the arrow keys to move the cursor to each of the different points Use the same method is used to edit both the upper and lower limit lines Pass Fail testing can be started after setting the limit lines 2 Use the remote commands to read back test results Manually setting the spectrum analyzer for testing can be time consuming Here we will use remote commands to set various parameters on the spectrum analyzer remotely We will briefly explain some of these commands below Frequency Commands Span Commands Amplitude Commands meas freq cen meas freq cen meas freq st meas freq st meas freq stp meas freq stp meas span meas Span meas span full meas refl unit meas refl unit meas refl meas refl Return the center frequency in kHz Sets the center frequency for example meas freq cen_100_mhz Returns the start frequency in kHz Sets the start frequency for example meas freq st_100_mhz Returns the stop frequency in kHz Sets the stop frequency for example meas freq stp_100_mhz Returns the frequency span settings Sets the frequency span sett
33. e ee ee ee ee ee a ee ee Motos FAS chan we boedei pee ep lacerteses secede chan ort fos ae t i 4 o a er fe Sewan E fo ff dF fewith 1H if p a 1 EES TEREE f i i 435 Ans ieee Oe ee ae Cs ae ay upreti t ad 500 ns ae 2 i F Z chan of PO ooo oo po J of Ie chan off eee re ee roe ter mere Do e E o ta al Buty Cycle Duty Cycle 2 3 1 49 48 Jeni oer i 50 07 Pott tt Rie Time pointa cleeecleceeZeceetecsetecesteeeetee sf Mise Time ji 284 5ns fo o FE dd 8 1s i 2 chan off boo oF Be Seem E 25ers CHi EDGE FAC Oo 506ml 0 258ns MCH1 EDGE FAC 2 5m B 1 80812MHz Spl a Semi 995 672kHz rail lusec sine wave Square wave with the same period However when we observe a sine wave and a square wave with the same amplitude and period is there a way to describe the difference between them Frequency domain measurements just provide a different view point First we will explain what frequency domain means Frequency domain means to observe the frequency composition of a signal If we add a sine wave signal that has a 1 microsecond period to a spectrum analyzer we will see an obvious signal on the scale at 1 megahertz MHz We know that frequency is the inverse of period Therefore a sine wave with a period of microsecond has a frequency of 1MHz You can measure voltage 15 16 GW INSTEK GRF 1300 User Manual and Teaching Materials from an oscilloscope and power dBm from a spectrum a
34. ected the corresponding LED light will be lit up e The Reset button is used to reset the GRF 1300 When reset the GRF 1300 will output a 0 10OMHz sine wave baseband signal and a carrier signal with a frequency 880MHz e The output port is used to output the set baseband signal GW INnSTEK GRF 1300 User Manual and Teaching Materials e The four digit display is used to display the frequency of the output baseband signal e TP4 test point 4 is used to used to monitor the output signal from the output port e The potentiometer knob is used to adjust the voltage of the output baseband signal Turn clockwise to increase the amplitude and turn anticlockwise to decrease its amplitude Figure A 4 i BaseBand TECIE Frequency MHz Baseband module 5 The UP and DOWN buttons on the RF Synthesizer FM module can be used to adjust the frequency of the carrier The carrier can be adjusted in 1MHz steps e The Four digit display is used to display the frequency of the carrier signal e FM in port and RF FM Output port are used to receive the FM signal and output the carrier signal respectively e TP2 TP3 and TP1 are used to monitor for breaks in the circuit For the position of each test point please see Figure A 7 10 GW INSTEK Introduction to the GRF 1300 Figure A 5 RF Synthesizer FM module Figure A 6 AM module Figure A 7 Circuit location of each test point RF Synthesizer FM 6 The AM module
35. ent goal ACPR and OCBW are important parameters in the measurement of RF modulated signals It is very important to master using a spectrum analyzer to measure ACPR and OCBW We must know how to utilize a spectrum analyzer to measure the RF parameters that are frequently used and to lay the foundation for future use ACPR is the ratio of the amount of power leaked to an adjacent channel from the main channel OCBW is the occupied bandwidth that contains a specific percentage of the total integrated power of the channel At present third generation mobile communication systems 3G are becoming ubiquitous while some countries and companies are looking to develop fourth generation mobile communication systems 4G This experiment therefore has a high practical value for the measurement of COMA RF power and related fields tem Quantity Note 1 SP 730 1 GRF 1300 2 100mm 1 800mm Adapter 1 NSMA 1 To understand ACPR measurement principles and to perform actual ACPR measurements aI Ae G N 2 Understand OCBW measurement principles and to perform actual OCBW measurements 19 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment principles Figure 7 1 RF power amplifier input and output Figure 7 2 Definition of ACPR 80 1 ACPR Measurement ACPR Adjacent Channel Power Ratio is the ratio of the amount of power leaked to an adjacent channel from the main channel It represents how much power from
36. er FM module to change the frequency of the carrier signal See if there is any change to the AM wave spectrum and record it Table 5 6 Step5 WO FT DOWN Peak Step16 63 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment 1 Changing modulating voltage results Table 5 4 Modulating Experiment results Experiment voltage results Changing the modulating voltage Vpp Mkz MHz Carrier power ____ Modulation index Lower sideband power Vpp 10 70 MAz MHz Carrier power Modulation index Lower sideband power Vpp 10 70 MHz MHz Carrier power 64 GW INnSTEK RF Communication and Signals Experiments Modulation index Lower sideband power ___ Conclusion 2 Changing the modulating signal frequency Table 5 5 Modulating Experiment results Experiment frequency results Changing the modulating 100kHz a signal frequency 0 10 F 20 30 AQ F T0 MHz MHz Carrier power Lower sideband power ___ 300Khz 10 dB Mkz Mkz Carrier power ____ Lower sideband power ___ 65 GW INSTEK GRF 1300 User Manual and Teaching Materials 600kHz MHz Mkz Carrier power Lower sideband power Conclusion 3 Changing the carrier frequency Carrier Experiment results Frequency Table 5 6 882MHz Experiment results Changing the carrier frequency MHz MHz 880MHz
37. g a signal can also be different For example when we analyze amplifiers filters and mixers we are no longer interested in measuring a function related to time but a response function which can be characterized by frequency In this experiment you will find that analyzing a signal in the frequency domain often has a lot of advantages compared to analyzing a signal in the time domain You will also find that there is a relationship that exists between the time domain and the frequency domain and will thus gain a better understanding of the theory behind the Fourier series tem Quantity Note 1 SP 730 1 GRF 1300 1 GDS 2204 1 800mm Adapter 1 NMA 1 Measure the harmonic content that is output from the baseband signal aI amp GQ N 2 Use the measurement results to verify the Fourier series theorem 3 Understand the internal relationship between the time domain and the frequency domain in a signal 4 Use this experiment to become familiar with how to measure the spectral characteristics of a typical signal such as the amplitude and frequency 39 GYVINSTEK Experiment principles Experiment contents Experiment steps 40 GRF 1300 User Manual and Teaching Materials Set the waveform on the GRF 1300 and measure the harmonic spectrum Switch to a different waveform and measure the harmonic spectrum Compare the differences The relationship between the time domain and the frequency domain has already been in
38. h a variety of experiments Understanding RF theory has been made easier by breaking the RF circuits into fundamental functions This allows students to see in detail how the theory relates to the practical aspects of the RF circuitry This system is a collection of different functions signal generation frequency modulation amplitude modulation GW INSTEK Introduction to the GRF 1300 Figure A 1 The GRF 1300 control panel Figure A 2 Reference platform GSP 730 Spectrum Analyzer communication and other functions Connecting different modules together can create a number of different RF circuit experiments Specific experiments will be highlighted in later chapters The GRF 1300 RF amp Communication Trainer is designed to modulate an audio signal with a carrier waveform The system takes into account the difficulties arising from RF circuit theory and knowledge It focuses on these theories and sets up experiments to understand the theoretical aspects of RF circuitry This also has the added benefit of increasing a student s interest to learn RF circuits ba GWINSTEK cGrrF 1300 AF amp Communication Trainer BaseBand RF Synthesizer FM a saat g t H T g hoga pome Y i GLUA i wad GWINSTEK GRF 1300 User Manual and Teaching Materials Package Contents This package contains the GRF 1300 unit RF cable 2 10cm RF cable 1 80cm a user manual CD a student book an antenna a power c
39. ifferent carriers so that multiple signals can be transmitted simultaneously These experiments start with amplitude modulation The spectrum analyzer is used to measure the characteristics of AM signals which has a great significance for students to master FM as well as AM principles and characteristics Item Equipment Quantity Note 1 Spectrum analyzer 1 GSP 730 2 RE amp Communication Trainer 1 GRF 1300 3 RF wire 2 100mm 4 RF wire 1 800mm 5 Adapter 1 N SMA 1 Learn the working principals of amplitude modulation 2 Use the spectrum analyzer to measure the AM characteristics of an RF signal Modulation is the process of moving a low frequency signal to a high frequency and then transmitting the high frequency signal Generally the low frequency signal carrying the original information is called the modulating signal or baseband signal The high frequency signal is known as the carrier signal After the carrier signal is modulated by the modulating signal the resultant signal is called the modulated wave There are three kinds of modulation methods that are used AM FM and phase modulation GW INSTEK RF Communication and Signals Experiments This experiment begins with AM to learn some modulation theory AM uses the modulating signal to control the amplitude of the high frequency carrier signal The modulating signal is used to alter the amplitude of the carrier in proportion to the amplitude of the modulating signal A high freque
40. ings for example meas span 10_mhz Sets the span to Full Span mode Returns the reference level unit Sets the reference level unit Parameters 1 dBm 2 dBmV 3 dBuV Returns the reference level in dBm Sets the reference level in dBm For example meas refl 30 GW INSTEK RF Communication and Signals Experiments Experiment contents Experiment steps Limit line meas lmtline on Turns the limit lines on Commands Parameters O low limit line 1 high limit line meas Imtline off Turns the limit lines off Parameters O low limit line 1 high limit line meas lmtline pas Turns pass fail testing on sfail_on 1 Set the upper and lower limit lines to perform a pass fail test on the signal from the GRF 1300 2 Use remote commands to remotely setup the spectrum analyzer 1 Turn on the GRF 1300 and GSP 730 NO Set the GRF 1300 to the power on default state 3 Connect the RF wire from the output port on the baseband module to the FM in port on the RF Synthesizer FM module o fe li 12 5 00 a2 2 ole Pa ooo o _ OOO KH ie O00 D we i 4 Set up the GSP 730 as follows e Center frequency 880MHz e Span SOMHz e Reference level 0dBm e RBW Auto sp QDecoo Ea Step2 Gdeoo HB Step3 Deo El ow Jay 5 Limit line Pass Fail test otep4 91 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment results
41. ion FM index Vpp 10 dB 0 10 F 20 30 70 MHz MHz 75 GW INSTEK GRF 1300 User Manual and Teaching Materials Frequency deviation FM index Conclusion 2 Changing the frequency of an FM signal Table 6 3 Modulating Experimental result Experimental frequency results Changing the frequency of 100Khz the FM signal MHz MHz 300Khz MHz MHz 600kHz MHz MHz 76 GW INSTEK RF Communication and Signals Experiments Table 6 4 Experimental results Changing the carrier frequency 1MHz 10 T0 MHZ MHz Conclusion 3 Changing the carrier frequency Carrier Experimental result frequency 875MHz 10 dB 70 Mhz Mkz 880MHz 10 10 MHz MHz 7 GW INSTEK GRF 1300 User Manual and Teaching Materials Question 78 890MHz MHz MHz Conclusion 4 Draw a table to record the time domain waveform of the AM 1 wave that is measured by the oscilloscope For FM waves if we keep the modulation signal amplitude constant and double the modulation signal frequency how will the frequency deviation and bandwidth change in the modulated signal Calculate the FM index of the modulation circuit through the measured data obtained from the spectrum analyzer GW INSTEK RF Communication and Signals Experiments Experiment 7 Using a Spectrum Analyzer in Communication Systems Relevant information Experiment equipment Experim
42. is network is intertwined with wireless signals of various frequency bands Although these signals are invisible and intangible we can use a spectrum analyzer to understand and analyze these wireless signals In this experiment the GSP 730 spectrum analyzer is used to capture some wireless signals in the environment This experiment will help students to become familiar with using spectrum analyzers as well as to arouse their curiosity in the field of RF signals Item Quantity Note 1 SP 730 2 Adapter 1 NSMA 3 Antenna 1 80 To become familiar with how to use the GSP 730 and how to use parameter settings such as frequency amplitude and markers Spectrum analyzers are mainly used to measure physical quantities such as the frequency and amplitude of a signal For basic operation the frequency range must be set first then the reference level amplitude Mikr 1 at 900 049999MH 9 0 dBm Ref 0 0dBm Am Frequency Start 697 55MHz Center 900 05MHz Stop 90 55MHz RBYW 50kHz Span 5 0MHz Sweep 14sec 31 GW INSTEK GRF 1300 User Manual and Teaching Materials The figure above is a screen shot from a typical spectrum analyzer display The horizontal setting is frequency and the vertical axis is amplitude Therefore a spectrum analyzer is basically used to perform frequency and amplitude related measurements We can operate a spectrum analyzer by using the Frequency Amplitude and other function keys in conjunction with
43. is used for amplitude modulation The AM in port and RF in port are used to input the modulating signal and the carrier signal respectively The AM output port outputs the amplitude modulated waveform AM output There are five test points Tp1 Tp2 Tp3 Tp4 Tp5 on the panel These five test points are set at different points in the circuit path of the connected modules Their specific locations are as shown in the Figure below They are turned on or off by their corresponding relays B1 B2 B3 B4 B5 An oscilloscope can be used to detect determine the status of the circuitry at these test points O Tp4 By Modulation CPU LF VCO wave T OTp OT p2 Vec FM in i 8 Install the GRF 1300 driver onto the PC 11 GW INSTEK GRF 1300 User Manual and Teaching Materials e Connect the GRF 1300 to the PC Below are the steps for installing the software Add the install software to the install directory Click next and a window as shown below appears Figure A 3 Hardware Installation Software installation The software you are installing for this hardware USB Communications Port has not passed Windows Logo testing to verify ts compatibility with Windows P Tell me why this testing is important Continuing your installation of this software may impair or destabilize the corect operation of your system either immediately or in the future Microsoft strongly recommends that you stop this installation now
44. ise floor of VBW2 is greater than that in VBW1 But notice that the average level of the noise floor remains the same The VBW filter only averages the noise level It doesn t affect the overall amplitude of the signal noise floor Figure B 8 Different VBWs ene eer Results lt Noise VBW1 27 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 28 GYVINnSTEK An Introduction to Spectrum Analyzers NOTES 29 GW INSTEK GRF 1300 User Manual and Teaching Materials RE COMMUNICATION and SIGNALS EXPERIMENTS 30 In this chapter we will explain the basic operating principals of a spectrum analyzer and introduce the measurement experiments Prior to this we will briefly explain how to operate the GW Instek GSP 730 spectrum analyzer For more detail about its operation please refer to the GSP 730 user manual Marker keys for setting Marker Main keys Peak Search for a Power Measurement Control keys Limit Line for setting Frequcncy paca Trace Amplitude Display Autoset GYNnsTEK csp 720 Numeric keypad RF input terminal GWINSTEK RF Communication and Signals Experiments Experiment 1 Basic Operation of a Spectrum Analyzer Relevant information Experiment equipment Experiment goals Experiment principles In addition to the sky oceans and forests there is an invisible intangible inaudible and complex electromagnetic network in our living environment Th
45. les of the absolute magnitudes of the sidebands for signals with a modulation index of 0 5 2 41 and 5 The FM circuit in the GRF 1300 uses a phase locked loop Using a PLL circuit for FM modulation not only solves the center frequency stability problems in direct FM modulation but also the narrow FM range limitations when using a crystal oscillator The spectrum of the modulating signal must be outside the of 71 GWINSTEK GRF 1300 User Manual and Teaching Materials low pass filter passband to achieve a phase locked FM wave When the center frequency of the VCO is locked on to a stable high frequency it allows the VCO to shift in frequency when the modulating signal is varied Figure 6 2 Modulating signals GRF 1300 FM 8 principle Crystal Phase Loop Voltage Oscillator detector Filter controlled Oscillator Experiment 1 Measure the FM wave spectrum contents 2 Observe how the amplitude of the modulating signal affects the FM wave frequency deviation 3 Observe how the frequency of the modulating signal affects the FM wave frequency deviation Experiment 1 Turn on the GRF 1300 and GSP 730 steps 2 Set the GRF 1300 as follows e Under the default state the state from power up turn the potentiometer to the minimum position e Connect the output port on the Baseband module to the FM in port on the RF Synthesizer FM module with an RF cable e Connect the RF FM output port
46. litude of the signal Step5 ep e 5 Change the span to 5MHz Set the center frequency to each of the above three frequency points in sequence so that you can observe each one more accurately Record these three frequency points in Table 1 1 otep6 F2 Set the center frequencies to each of the three frequency points step GDC Es 6 Testing the wireless signals in the environment is shown in the picture below gt FS N KES J SOSO p 0o00 oD nen OOo GS 6 eon O00 O ey i m7 O00 Experiment results 33 GW INSTEK GRF 1300 User Manual and Teaching Materials Question 34 F0 C MHz O MEZ Frequency Amplitude Mhz MHz Frequency Amplitude ____ Table 1 1 Frequency and amplitude of mobile phone s transmitter signal In addition to the mobile phone signal what other wireless signals can be measured in the environment GW INSTEK RF Communication and Signals Experiments Experiment 2 Measuring a Baseband Waveform Relevant information Experiment goals Experiment principles Experiment contents Experiment steps Relative to oscilloscopes spectrum analyzers have many outstanding advantages They are also the primary measurement tool for measuring frequency domain data Learning how to use a spectrum analyzer is an essential skill that every student must master to gain RF knowledge By measuring a baseband signal this experiment
47. magnetic fields Relative Humidity lt 80 Altitude lt 2000m Temperature 0 C to 40 C Pollution Degree EN 61010 1 2010 specifies pollution degrees and their requirements as follows The device falls under degree 2 Pollution refers to addition of foreign matter solid liquid or gaseous ionized gases that may produce a reduction of dielectric strength or surface resistivity Pollution degree 1 No pollution or only dry non conductive pollution occurs The pollution has no influence Pollution degree 2 Normally only non conductive pollution occurs Occasionally however a temporary conductivity caused by condensation must be expected Pollution degree 3 Conductive pollution occurs or dry non conductive pollution occurs which becomes conductive due to condensation which is expected In such conditions equipment is normally protected against exposure to direct sunlight precipitation and full wind pressure but neither temperature nor humidity is controlled Location Indoor Relative Humidity lt 70 Temperature 10 C to 70 C GW INSTEK GRF 1300 User Manual and Teaching Materials Disposal Do not dispose this device as unsorted municipal waste Please use a separate collection facility or contact the supplier from which this ps instrument was purchased Please make sure discarded electrical waste is properly recycled to reduce environmental impact Power cord for the United Kingdom When using
48. ment 1 Measure the waveform and spectrum of an AM wave contents 2 Measure the spectrum of the AM wave with different carrier frequencies and with modulating signals with different amplitudes Experiment 1 Turn on the power to the GRF 1300 and GSP 730 steps 2 Set the GRF 1300 as follows e Set the GRF 1300 to the default power on state e Connect the output port on the Baseband module to the AM in port on the AM module with an RF cable e Connect the RF FM output port on the RF Synthesizer FM to the RF in port on the AM module with an RF cable e Turn the potentiometer clockwise to the end 3 Connect the AM output port to the input port of the spectrum analyzer with the 800mm RF cable 61 GW INSTEK GRF 1300 User Manual and Teaching Materials 62 0000 00ga 0000 0000 QOOO r Yieooa 0000 E0008 4 Set up the GSP 730 as follows e Center frequency 880MHz e Span SMHz e Reference level 0dBm e RBW Auto EDoaooo Ea Do Dot se Daksa 5 Use the Marker function to measure the carrier component of the AM wave on the spectrum analyzer and the power of the upper and lower sidebands Use the oscilloscope to measure the voltage at TP4 in relation to the position of the potentiometer i e the modulating amplitude Draw the spectrum diagram in Table 5 4 steps sp GD oBooo o 6 Turn the potentiometer counterclockwise to the half way mark Measure the voltage with the oscilloscope By changing
49. nSTEK NOTES Test for Learning Outcomes 99 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 100 GWINSTEK Test for Learning Outcomes NOTES 101 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 102 GW INSTEK Appendix A ppEN DIX We have included some commonly used conversion tables for use with the questions dBm Conversion Table dBm dBuV and dBmvV are all absolute units i e they represent a physical quantity The corresponding conversion tables are below 30 0 001 7071 07 76 9897 16 9897 25 00003 1257433 81 9897 21 9897 0 010 22360 68 86 9897 26 9897 0 032 39763 54 91 9897 31 9897 0 100 70710 68 96 9897 36 9897 50316 12574334 101 9897 419897 0 100022360680 106 9897 46 9897 5 3162 39763536 111 9897 519897 103 GWINSTEK GRF 1300 User Manual and Teaching Materials The relationship between dB and dBc Question Answer Explanation 104 The figures in the table above are based on a 50Q load As an example as 30dBm is equal to 0 001mW or 10 W therefore with a 50Q load it is 7071 07 uV or 0 007071mV The formulas and derivations from the above table are dBm 10 gt Vy JPxR gt dBuV 20x Be uV P inmW further dBm 10 x ie E dBmV 20x log mw mV As for dB and dBc they are relative units In terms of power a difference of 20dB is equal to a difference of 100 times What is the difference between 0dBm and 50dBm Is it 50dB o
50. nalyzer Voltage and power can be converted from one to the other so both of them can be used to display the strength of a signal Here we introduce a basic concept first Each frequency point in the spectrum represents a sinusoidal wave could be a sine or cosine of a single frequency L a LA i or 1 J Y f E k F E a i O E l E a oh perdpauoaed ie peupuerere i pre l E E F ore Hy a W Thar sal dna lL LAL povided aid HHobeded What about a square wave We will now explain how a square waveform and sine waveform are different to each other in the frequency domain If we input a square wave witha period of 1 microsecond into a spectrum analyzer its waveform performance we usually to say its spectrum or frequency distribution is as follows 1 I l fi i j BT Da Vee pee 0 W OAT Al ree F Il O PATS i k4 viih A Wy Atl sn i ATT mi WTN iy If we compare it with a sine wave spectrum we can observe that in addition to the point at the1MHz scale other signal points also appear at higher frequencies and with decreased amplitudes Therefore it shows that a square wave also includes a combination of signals that are multiples of the frequency baseband in addition to the IMHz base frequency fundamental frequency We can see a classic relationship between the time domain and frequency domain in the illustration below A square wave signal in the time domain can be decomposed into multiple basic harmonic waves
51. ncy carrier signal that is amplitude modulated is called an AM wave AM waves are divided into ordinary AM waves double sideband AM waves with suppressed carrier transmission and single sideband AM waves with suppressed carrier transmission 1 The formula to express the modulated waveform is as follows Assuming that the modulating signal is a sine wave of a single frequency Q 27fo And uo t Uom cosQ t Uomcos2afo t 5 1 then the carrier signal is u t Usm COSO t Ugmcos2mf t 5 2 Because the carrier frequency remains unchanged after amplitude modulation and the amplitude of an AM wave is proportional to the modulating signal therefore the modulated wave can be expressed as below uam t Uam Dcos t Urm 1 m cosQ t cos t 5 3 To simplify the analysis we set the initial phase angle of both waveforms to zero In formula 5 3 ma is known as the degree of AM modulation or the AM modulation index kaU am Namely ma y Lj om This equation indicates to what degree the carrier amplitude is controlled by the modulating signal The constant k is a proportional constant determined by the modulation circuit The AM modulation index should be less than or equal to 1 When the AM modulation index is greater than 1 it is called over modulation and will distort the modulated signal We can see from this that the AM wave also oscillates at a high frequency Its amplitude varies regularly envelope changes
52. noise Caution Be sure to tighten the connectors when connecting the RF cable 53 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 54 GYVINnSTEK RF Communication and Signals Experiments NOTES 59 GWINSTEK GRF 1300 User Manual and Teaching Materials NOTES 56 GYVINnSTEK RF Communication and Signals Experiments NOTES 57 GW INSTEK GRF 1300 User Manual and Teaching Materials Experiment 5 AM Signal Measurement Relevant information Experiment equipment Experiment goals Experiment principles 58 Message signals are usually of a low frequency In general these low frequency signals are not appropriate for transmission Therefore modulation is required to transmit messages for communication and test systems Modulation is a signal adjustment method used in signal transmission It is used to modulate a low frequency signal which carries information with a signal of an appropriate frequency This is used to solve problems associated with the amplification and transmission of weak signals The role of modulation in RF communication systems is essential Not only is modulation used to modulate the original low frequency signal and its transmission but it is also used for frequency division multiplexing FDM If signals with the same frequency range are transmitted on the same channel at the same time they can easily interfere with each other and hence why they are first modulated onto d
53. nstructed on how to use a spectrum analyzer Attenuator An attenuator on the RF input path can increase the dynamic range of the input signal level or provide more input protection to the spectrum analyzer Referring to Figure B 2 the attenuator limits the signal level coming to the mixer RF end to a certain level If the input signal is above a reference level it can cause measurement errors or cause spurious noise Figure B 2 Attenuator RF Input Detection amp Display Attenuator Unit Tunable LOs Resolution Bandwidth Filter When the input signal frequency is converted to an IF a RBW resolution bandwidth filter is used to distinguish the signals that are close to each other in frequency Figure B 3 shows this concept 24 GW INSTEK An Introduction to Spectrum Analyzers Figure B 3 Basic structure of RF Input a resolution bandwidth filter Figure B 4 The effect of different RBWs 1 Mixers Detection amp Display Unit Attenuators Tunable LOs Figure B 4 shows how two different RBW filters distinguish between two signals that are close to each other in frequency The bandwidth of RBW2 is wider that of RBW1 Signal under test i Results RBW1 RBW2 After passing the narrower RBW1 filter the components of the two tone signal are clearly distinguished from each other as a result But in the wider RBW2 filter the result is not as clear as RBW1 We can predict tha
54. ord and so on No oe ee No 7 EZ User manual and software Student Textbook N SMA Adapter RE amp Communication Trainer Spec ine Square Triangle Triangle 0 1 1MHz 10kHz Harmonics Distortion lt 30dBe Frequency Accuracy 0 15MHz 245MHz 870M 920M Adjustable Range tep IMEZ Power Range gt 15dBm Deviation AM Peak Difference gt 18dBm urn circuits on or off by remote command for the diagnostic experiments Communication GW INSTEK Introduction to the GRF 1300 Usage Instructions Procedure Figure A 3 Connection diagram between different modules 1 For safety purposes please connect the unit to the correct AC power source 100V 240V 50 60Hz Make sure the ground terminal is properly earthed to prevent electric shock The power socket and USB port are on the rear panel The power switch is on the upper left hand side of the device AC 100 240 a 50 A0H7 TVA USB port AC socket Power switch 3 When using several modules together at the same time connect each module with the appropriate RF cable AF amp Gommumication Trainer RF Synthesizer FM 8888 z9 Frequency MHs Ti a we 4 The UP and DOWN buttons on the Baseband module can be used to adjust the frequency of the baseband signal The baseband module is adjustable in 10kHz steps e WAVE Select is used to select three different baseband waveforms When the waveform is sel
55. own to a frequency band that detection circuitry can handle For example a 2 4GHz signal needs to be down converted to several MHz before the Detection amp Display unit can process the signal Therefore a spectrum analyzer must be able to reduce the frequency band down to several MHz The first half of a spectrum analyzer is called the radio frequency module and its task is to reduce the input signal frequency A mixer and a bandpass filter are used to decrease the frequency they can raise the frequency as well The mixer is a component with three ports two inputs and one output Assume that the two input frequencies on input port are frr and fto respectively and then the output frequency will be fir fir is made of two signals of different frequencies fLo frr and fot frr that appear on the output port at the same time One signal is the sum of the input signals and the other is the difference Determining which of the IF signals that will be used depends on the system and subsequent bandpass filter design As for why the three ports are named after RF LO IF they are just the conventional terms that are used 23 GW INSTEK GRF 1300 User Manual and Teaching Materials Figure B 1 The basic structure of a _ l broadband RF Input Detection receiver amp Display Unit Ay Tunable LOs Next we are going to introduce the other basic functional blocks that a spectrum analyzer is composed of These blocks are often mentioned when i
56. pment such as mice and keyboards The working principles behind a wireless mouse and that of a traditional mouse are the same The only difference is that the X amp Y position as well each button press is transmitted wirelessly via a transmitter The wireless receiver then passes this information to the host after decoding the signal The driver then tells the operating system to convert the signal to mouse actions Measure the frequency and power of the signal that is transmitted from a wireless mouse 1 Connect the antenna to the input port of the spectrum analyzer 2 Set up the GSP 730 as follows e Center frequency 2 4GHz e Span 200MHz e Reference level 20dBm e RBW Auto sp Dao sp GDooooc Es sep GDacoo El Step4 ep 3 3 Turn the wireless mouse on sep GD o Ea Step6 87 GYVINSTEK GRF 1300 User Manual and Teaching Materials 4 A connection diagram is shown below GWINSTEK Ger 726 LARET m 0000 F am ae 0000 3000 E O lecco 0000 OOOO A blue tooth device or wireless network card can also be used in the same way to create a signal to measure Experiment results MHz Mkz Transmitting frequency Transmitted signal power Question What are the advantages for a wireless mouse to operate in the 2 4 G bandwidth Caution Use the Peak Hold function on the spectrum analyzer to capture the signal emitted from the wireless mouse It is not easy to d
57. r 50dBm 50dB OdBm 1mW 50dBm 10 mW therefore the difference of both is 10 times which equal to 50dB or a difference of 0 99999mW And 0 99999mW is equal to 0 0000434dBm 0dBm 50dBm 10 mW 100W Obviously 50dBm is the wrong answer GW INSTEK Appendix Resistor Values in 1 type Resistance Attenuators 500 R1 R3 B 900 D955 yng s a agg aang B nao ggg D 7 1073 aso OOOO on OOOO O On na agg ggg Bos ang gg 40 _ 105 GW INSTEK GRF 1300 User Manual and Teaching Materials Resistor Values in T type Resistance Attenuators R1 R3 500 m B 50Q dB RO R RB 6 16 61 6693 166 0 9 12 5 80 9 12 1 53 7 31 1 53 3 81 0 59 3 81 397 5 14 597 8 01 0 62 8 01 9 92 6 81 9 92 1 71 3 5 7 1 71 106 GYVINSTEK Appendix Modulation Index and Sideband Amplitude Comparison Table Modulation index 0 00 0 25 0 5 1 0 1 5 2 0 2 41 2 5 3 0 4 0 5 0 5 53 6 0 f 0 6 0 6 65 9 0 10 0 12 0 Carrier 1 1 00 0 98 0 12 0 94 0 24 0 77 044 0 51 0 56 0 27 0 58 0 0 52 0 05 0 50 0 26 0 34 0 40 0 07 0 18 0 33 0 03 0 11 0 23 0 35 0 43 0 45 0 49 0 36 0 05 QO 0 34 0 13 0 15 0 268 0 24 0 30 0 00 0 30 0_ 17 0 17 0 23 11 0 29 0 10 0 06 0 24 0 23 0 14 0 18 0 27 0_06 0 06 0 22 0 23 0 01 0 0 27 09 0 25 0 25 0 04 0 25 0 05 0 22 0 08 0 02 0 06 0 13 0 20 0 22 0 31 0 43 0 36 0
58. rserserserserserseesersersesse 108 GW INSTEK GRF 1300 User Manual and Teaching Materials SAFETY INSTRUCTIONS This chapter contains important safety instructions that should be followed when operating and storing the GRF 1300 Read the following before any operation to ensure your safety and to keep the GRF 1300 in the best condition Safety Symbols These safety symbols may appear in this manual or on the instrument Warning Identifies conditions or practices that could result in injury WARNING or loss of life Caution Identifies conditions or practices that could result in cdc damage to the GRF 1300 or to other objects or property DANGER High Voltage Attention Refer to the Manual Protective Conductor Terminal Earth Ground Terminal Do not dispose electronic equipment as unsorted municipal waste Please use a separate collection facility or contact the supplier from which this instrument was purchased p4 i oO gt e Safety Guidelines General e Do not place heavy objects on the device Guideline e Do not place flammable objects on the device A N CAUTION Avoid severe impact or rough handling that may damage the device e Avoid discharges of static electricity on or near the device e Use only mating connectors not bare wires for the terminals e The device should only be disassembled by a qualified technician GYVINSTEK Safety Instructions Power Supply WARNING Fuse N WARNING
59. t if the resolution bandwidth of RBW2 is wider we could even misinterpret the result as only one signal This will also happen if these two signals are even closer together in frequency Another case is when the amplitude of one signal is much higher than the other the smaller signal can still be detected using RBW1 but it is obscured if RBW2 is used Figure B 5 illustrates this difference This is why these filters are known as resolution bandwidth filters 25 GWINSTEK GRF 1300 User Manual and Teaching Materials Figure B 5 The effect of different RBWs 2 Signal under test RBW Results RBW1 RBW2 Detector Following the RBW filter the detector detects the power and coverts it to DC voltage via an ADC so that it can be displayed Figure B 6 Detector Display Unit Detector Attenuators A Tunable LOs Video Bandwidth Filter However a filter is employed after the detector to filter out the noise generated by the detector This is the function of the VBW video bandwidth filter as shown in Figure B 7 Figure B 7 VBW filter 26 RF z gt Display Input i Unit Attenuators BPFs RBW Detector VBW Filter Filter Tunable LOs GW INSTEK An Introduction to Spectrum Analyzers Figure B 8 shows how the VBW affects the displayed output If the signal under test passes through two different VBW filters in which VBW1 is less than VBW2 we can see that the magnitude of the no
60. than the frequency of the carrier signal At the peak of the positive half period the angular frequency of the modulated signal is at its peak In the negative half period of the modulating signal the frequency of the modulated signal is lower than the frequency of the carrier signal and its angular frequency is at its lowest The angular frequency of an FM wave changes in response to changes in the modulation signal Then 0 tAwcosQrt In this formula o is the angular frequency of the carrier wave Aw 69 JO GWINSTEK GRF 1300 User Manual and Teaching Materials is the offset of the angular frequency determined by the modulating signal Uo The general expression for the FM signal t u t Uem COS Wet ky uo t dt o Uem cos ct kf U om cos Qtdt 0 Ucm cos ct He sin Q1 Qo kU am _ AQ Assume that My Q Q In this formula Myis called the FM index Awn is called the maximum angular frequency deviation its value is proportional to the amplitude of the modulating signal 2 Frequency domain analysis Expressed by the time domain FM wave ae Oi E u t Ucm cos Wet Uem cos ct mf sin Qt Qo Let the initial phase angle be 0 and expand as follows u t Ucm COS Wct cos my Sin Qt sin Wet sin m e sin Qt When mp lt lt 1 cos mysin Qt 1 sin mysin Q mpsin Qt Then we get u t Uem COS Wet mUem SiN Get sin Qt mfUem mfUem Uem COS Wet Z ae O d
61. the device in the United Kingdom make sure the power cord meets the following safety instructions NOTE This lead appliance must only be wired by competent persons 1 warninc THIS APPLIANCE MUST BE EARTHED IMPORTANT The wires in this lead are coloured in accordance with the following code Green Yellow Earth Blue Neutral Brown Live Phase As the colours of the wires in main leads may not correspond with the coloured marking identified in your plug appliance proceed as follows The wire which is coloured Green amp Yellow must be connected to the Earth terminal marked with either the letter E the earth symbol or coloured Green Green amp Yellow The wire which is coloured Blue must be connected to the terminal which is marked with the letter N or coloured Blue or Black The wire which is coloured Brown must be connected to the terminal marked with the letter L or P or coloured Brown or Red If in doubt consult the instructions provided with the equipment or contact the supplier This cable appliance should be protected by a suitably rated and approved HBC mains fuse refer to the rating information on the equipment and or user instructions for details As a guide a cable of 0 75mm2 should be protected by a 3A or 5A fuse Larger conductors would normally require 13A types depending on the connection method used Any exposed wiring from a cable plug or connection that is engaged in a live socket is extremely
62. they rely on the phase of the modulated signal and not the amplitude to carry the baseband signal The FM circuit in this experiment uses a phase locked loop The phase locked loop circuit principles described earlier can be used to study the application of a phase locked loop circuit for this section tem Quantity Note 1 Spectrum analyzer 1 GSP 730 1 GRF 1300 2 100mm 1 800mm Adapter 1 NSMA 1 Understand the working principals of frequency modulation aI G2 N 2 Use a spectrum analyzer to measure the FM characteristics of an FM wave 3 Master phase locked loop principals that are used in FM 1 Time domain analysis Frequency modulation is a type of modulation in which the instantaneous frequency deviation of the modulated signal with respect to the frequency of the carrier signal is directly proportional to the instantaneous amplitude of the modulating signal Assume that the modulating signal is uolt UgmcosQt GW INSTEK RF Communication and Signals Experiments Figure 6 1 An FM signal varying to the change of a modulating signal And the carrier signal is u t Uem COSO t UcmCOS2 Afe t An FM signal varying to changes in the modulating signal is shown in Figure 6 1 In the positive half period of the modulating signal the frequency of the modulated signal is higher
63. troduced in chapter 3 We won t repeat it again here We will become familiar with using a spectrum analyzer and how to use the GRF 1300 by analyzing the spectrum of a simple triangle and square wave signal 1 Turn on the GRF 1300 and the GSP 730 2 Set the GRF 1300 baseband as follows e Waveform triangle e Frequency 1MHz e Turn the input amplitude knob clockwise to the end Step1 oe gt REE o X Wave Select ia sep gl gt E 3 UP Step3 N Amp Adj 3 Connect the baseband signal from the output port on the GRF 1300 to the input terminal on GSP 730 with the RF cable r gA r ha p hy ra a fra i L Pi P B raj fra hos i A a i i F a Communication 9000 0000 0gag OOOO JasoBand QO00 leon 0000 000 iia aE ta 4 Set the GSP 730 as follows e Center frequency 15MHz e Start frequency OkHz e Stop frequency 30MHz Span 30MHz GW INSTEK RF Communication and Signals Experiments e Reference level 0dBm e RBW Auto Step1 f son TOOD Ex Step2 aoco TE Step3 Doo D Step4 5 Observe the spectrum that appears Use the Marker function on the spectrum analyzer to determine the harmonic ratio and draw the spectrum in Table 3 1 Peak Step5 After step 4 is done make sure the Delta marker is used for the next steps and not the Normal marker Set the Delta Marker to the peak point of each harmonic and make a record by dr
64. urement of the RF Carrier Relevant information Experiment equipment Experiment goals Experiment principles 46 In communication systems RF signals generally use carrier signals As a low frequency signal cannot be easily transmitted very far over air the low frequency message such as voice must be placed into a higher frequency signal so it can be being transmitted over a distance using an antenna This high frequency signal carries the message and is thus called the carrier In this experiment we will perform basic measurements on RF signals and measure important parameters such as phase noise and harmonic distortion The carrier of this experimental system is generated by a PLL Phase locked loops are widely used as phase locked receivers or for phase locked frequency modulation and demodulation They are also often used as a local oscillator for transmitters and receivers We must learn in detail the working principles of PLL circuits when we study RF circuits This experiment allows students to comprehend high frequency signals by measuring the carrier frequency spectrum It also makes students recognize the basic structure of a PLL circuit In the following experiments we will further study the locked and unlocked conditions of a phase locked loop tem Quantity Note 1 SP 730 2 1 GRF 1300 3 1 800mm 1 Adapter I NMA Measure an RF signal from the GRF 1300 RF amp Communication Trainer Also perform measurements
65. ve a number of set ranges therefore it fine to set the RBW to Auto mode 2 OCBW measurement OCBW measurement is for measuring the bandwidth that the channel occupies for a specified amount of power This is used to measure the occupied bandwidth as a percentage of the channel power for a specified amount of power Commonly used parameters for the measurements are channel bandwidth channel spacing and OCBW 1 Measure the ACPR from the FM signal produced by the GRF 1300 2 Measure the OCBW from the FM signal produced by the GRF 1300 1 Turn on the GRF 1300 and GSP 730 2 Set up the GRF 1300 as follows e Set the GRF to the power on default state e Use the RF wire to connect the baseband output to the FM in port on the RF synthesizer FM module e Connect the output terminal on the RF FM module to the input terminal on the spectrum analyzer with the RF cable 81 GW INSTEK GRF 1300 User Manual and Teaching Materials ACPR measurement 82 ct GE RSTEX GHF4300 AFi Coemmenication Trainer 0000 0000 l k J 1 i QOO0 OOOO E T E E C ri f T 900g 0000 3 Set up the GSP 730 as follows e Center frequency 880MHz e Span 10MHz e Reference level 10dBm e RBW Auto sp DaAooo M Step2 cococ tA sep GDeacoo Ei sept GD a ES Adjust the FM frequency deviation to IMHz 2MHz in total with the amplitude knob Ref 10 0dBm
66. y to 910MHz and again measure the power and phase noise corresponding to the frequency Step11 2 sp D0000 El Step13 Record the carrier power Set the deviation carrier frequency fn to a deviation of 100kHz Use the Delta Marker function on the spectrum analyzer to measure the A value sep oM oo C 4 Record the value then calculate the phase noise according to the formula and record the spectrum and measurement results in Table 4 3 50 GW INSTEK RF Communication and Signals Experiments Experiment 1 Measurement of the RF signal spectrum results Table 4 1 RF Signal Spectrum dB i MHz MHz 2 RF Signal Harmonic measurements Table 4 2 RF 10 Signal Spectrum dB MHz MHZ MHz MHz 3rd Harmonic measurement 51 GW INSTEK GRF 1300 User Manual and Teaching Materials Table 4 3 Phase Noise measurement results 52 3 Phase noise measurement results Carrier Experiment results Frequency 875MHz MHz Mkz Carrier frequency Output power ____ Phase noise gooMHz MHz MEZ Carrier frequency Output power Phase noise 910M Hz MHZ MHz Carrier frequency Output power Phase noise GW INnSTEK RF Communication and Signals Experiments Questions 1 A PLL circuit is formed by which parts Explain the function of each part 2 What are the advantages of a PLL 3 Explain the causes of phase noise How can we improve phase
67. ynamically measure the signal 88 GW INSTEK RF Communication and Signals Experiments Experiment 9 Production Line Applications Relevant A spectrum analyzer can be used in Pass Fail testing of RF information communication products Testing can be done either manually with a stand alone instrument or via remote control using a PC When using remote control the spectrum analyzer parameter settings and test results can be returned remotely This saves a lot of time and can improve the efficiency of a production line In this experiment we will imagine that the GRF 1300 is ina production line environment We will use the limit line function to perform a simple test to see if a product has passed the test and return the test results using remote commands tem Equipment Quantity Note aT 4 SP 730 Sqn 2 1 GRF 1300 3 RFwire 1 800mm 100mm 4 Adapter 1 N SMA Experiment 1 Learn how to edit the pass fail limit lines and understand how goals to perform pass fail testing 2 Use remote commands to read back test data from the spectrum analyzer Experiment 1 Limt line editing and Pass Fail testing principles The upper and lower limit lines apply throughout the entire frequency span The limit lines can be used to detect if the signal amplitude is above or below a set amplitude level The judgment of the pass fail test is shown on the bottom of the screen To create a limit line edit the ten points in the lower Limit Lin

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