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AFG-3000 Series User Manual

1. 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 signal Compare this to the original 100kHz baseband signal and record it to Table 6 3 S o a On gt 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 75 76 GWIMSTEK GRF 1300A User Manual and Teaching Materials Step10 eo ee AOE UP ON N mL 10 Change the
2. e Set the GRF 1300A 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 63 GWIMSTEK GRF 1300A User Manual and Teaching Materials 64 oo oe f gt gt moo 0 e 4 O G ers a 200 eS mOoO08 i 4 Set up the GSP 730 as follows e Center frequency 880MHz e Span SMHz e Reference level 0dBm e RBW Auto occo Ea Do eo t se Da a 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 GDoBooocs 6 Turn the potentiometer counterclockwise to the half way mark Measure the voltage with the oscilloscope By changing 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 volt
3. 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 62 GWINnSTEK RF Communication and Signals Experiments Figure 5 3 Spectrum of an AM wave pny duy 1 2 Maven 1 2 MaUecm Q We Q 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 Experiment 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 1300A and GSP 730 steps 2 Set the GRF 1300A as follows
4. GW INnSTEK Test for Learning Outcomes NOTES 113 GWIMSTEK GRF 1300A User Manual and Teaching Materials NOTES 114 GW INnSTEK Test for Learning Outcomes NOTES 115 GWIMSTEK GRF 1300A User Manual and Teaching Materials NOTES 116 GWINSTEK Appendix A ppENDIx 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 25 000812874330 81 9897 21 9897 20 ony arog sty ast 15 00323976354 91 9897 31 9897 a a 9897 O e ee a O 4 000 223606 80 106 9897 46 9897 eee eee 9897 10 10 000 70710678 116 9897 56 9897 E 2o t0000 o 223006798 a S8 9897 nae es a A 30 1000 000 7071067 81 136 9897 76 9897 117 GWIMSTEK GRF 1300A User Manual and Teaching Materials The relationship between dB and dBc Question Answer Explanation 118 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 V 4PxR 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 differ
5. gt ism Time ob oi l eee cle elec ccleceeleeeeteeeetess ste g Rise Time li 224 5nz 11 9 18 ne ae a ar ESE a eee Oe ee Re TED SOE See SO jz Ai i B 50m Weseare CHI EDGE FAC Ba 50AM 25ers CHi EDGE FAC 2 Sem B 1 80812MHz E z Semi G 298 672kHz nl 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 16 GWINnSTEK Overview of the Time and Frequency Domain from an oscilloscope and power dBm from a spectrum analyzer 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 4 a t ri kS n rt 1 F CON ee Wyl PAA AEA EAA An N R 3 oP 7 Ta E
6. Average function cannot be used as it uses a logarithmic method to calculate the average 87 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment 8 Measurement of communication products Relevant information Experiment equipment Experiment goals 88 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 IrDA 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
7. 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 25 GWIMSTEK GRF 1300A User Manual and Teaching Materials Figure B 3 Basic structure of RF Input a resolution i bandwidth filter ow amp Display Unit Mixers Detection 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 Figure B 4 Signal under test The effect of different RBWs im 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 that 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
8. 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 GUVINSTEK cGrr 1300A Base Band er RF Synthesizer FM a588 i 3888 Mixer BandpassFilter GWIMSTEK GRF 1300A User Manual and Teaching Materials Package Contents This package contains the GRF 1300A unit RF cable 3 10cm 1 20cm RF cable 2 80cm a user manual CD a student book an antenna a power cord and so on ca see AC power cord 100 240V 50 60Hz a software Student 1 RF amp Communication Textbook Trainer Product Specifications and Function Function Item Spec aveforms ine Square Triangle 0 1 3MHz Frequency Range Triangle 0 1 1MHz 10kHz 21 5Vpp Amplitude gt 0 75V pp into 50Q Harmonics Distortion lt 30dBe Frequency Accuracy 015MHz gt 45MHz 870M 920M Adjustable Range tep IME Power Range 2 15dBm Max Frequency AM Beak Difference gt 184Bm 3 GW IINSTEK Introduction to the GRF 1300A Mixer modulation Bandpass Filter urn circuits on or off by remote command for the diagnostic experiments Communication Usage Instructions Procedure 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 2 The power socket and USB port are on the rear panel The
9. 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 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 15 16 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 01 121 GWIMSTEK GRF 1300A 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 1300A 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 Radiated Clas
10. Synthesizer FM module can be used to adjust the frequency of the carrier The carrier can be adjusted in 1MHz steps 10 GWINnsSTeEK Introduction to the GRF 1300A 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 Figure A 5 RF Synthesizer FM module 6 The AM module 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 Figure A 6 AM module AM output The mixer can convert the RF signal into an intermediate frequency signal or it can do the opposite and convert the intermediate frequency signal into an RF frequency signal in order to transmit or process the carried message respectively 11 GWIMSTEK GRF 1300A User Manual and Teaching Materials BandpassFilter BPF output 7 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 oscillo
11. _ 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 GWINnSTEK 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 equipment 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 t
12. analyzing the frequency spectrum with a spectrum analyzer 3 To measure mixer parameters such as conversion gain and port isolation 1 Introduction to the concept of mixing The mixer is used for frequency conversion Mixing is also known as conversion Mixing is used to convert a modulated signal with a carrier frequency fe to a modulated signal with the carrier the frequency J for processing at the next circuit This process is called frequency shifting shifting of the frequency spectrum Frequency conversion by the mixer needs to maintain the modulation from the modulated carrier unchanged so it still carries information and has no distortion The basic function of a mixer is to maintain the modulation of the GW INSTEK RF Communication and Signals Experiments Figure 10 1 The mixer circuit Figure 10 2 Mixer signal diagram modulated signal constant only to increase up conversion or decrease down conversion the carrier frequency From the spectrum point of view the essence of mixing is to linearly move the spectrum of the modulated signal along the frequency axis Therefore a mixer circuit must be composed of a non linear device with a multiplicative function as well as band pass filters as shown in 10 1 ae The mixer multiplies the modulated signal us t with carrier frequency fe and the local oscillator signal z t with the oscillation frequency J as shown in figure 10 2 According to the multiplicati
13. 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 z 1 GRF 1300A 3 1 800mm 1 Adapter O I NMA Measure an RF signal from the GRF 1300A RF amp Communication Trainer Also perform measurements 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 47 GWIMSTEK GRF 1300A User Manual and Teaching Materials Figure 4 1 PLL circuit structure Figure 4 2 Phase noise definition 48 UO U0 UO O Ab
14. characteristics of an AM waveform The mixer can convert the RF signal into an intermediate frequency signal or it can do the opposite and convert the intermediate frequency signal into an RF frequency signal in order to transmit or process the carried message respectively 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 through a variety of experiments Understanding RF theory has been made easier by breaking the RF circuits into fundamental GW INSTEK Introduction to the GRF 1300A Figure A 1 The GRF 1300A control panel Figure A 2 Reference platform GSP 730 Spectrum Analyzer 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 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 1300A 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
15. known as resolution bandwidth filters 26 GWINnSTEK An Introduction to Spectrum Analyzers Figure B 5 Signal under test The effect of different RBWs 2 a 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 RF 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 RF i Display Input Unit Attenuators BPFs RBW petector VBW A Filter Filter Tunable LOs 27 GWIMSTEK GRF 1300A User Manual and Teaching Materials 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 noise 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 Slgnarunder A Results halpa ha a lt Noise VBW1 28 GYVINSTEK An Introduction to Spectrum Analyzers NOTES 29 GWIMSTEK GRF 1300A User
16. 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 1300A 2 Use remote commands to remotely setup the spectrum analyzer 1 Turn on the GRF 1300A and GSP 730 2 Set the GRF 1300A 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 GRE 3008 0000 ai r te ss ar i _ ey ee er Fe Lue aed Ae We ied ooo 0000 s22 0080 99g 0000 4 Set up the GSP 730 as follows e Center frequency 880MHz e Span SOMHz e Reference level 0dBm e RBW Auto sp GDeceo 2 Ei sp GDooo cp Deo a sept GD a Ss 5 Limit line Pass Fail test 93 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment results sep GID o El sep Bo ET 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 1300A 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
17. phase noise according to the formula and record the spectrum and measurement results in Table 4 3 Experiment 1 Measurement of the RF signal spectrum results Table 4 1 RF Signal Spectrum dB i MHZ MHz 2 RF Signal Harmonic measurements 52 GWINnSTEK RF Communication and Signals Experiments Table 4 2 RF 10 Signal Spectrum dB l MHz MHZ 2nd Harmonic measurement 3rd Harmonic measurement 53 GWIMSTEK GRF 1300A User Manual and Teaching Materials Table 4 3 Phase Noise measurement results 54 3 Phase noise measurement results Carrier Experiment results Frequency 8 5MHz MHz MHz Carrier frequency Output power Phase noise 900MHz MHz MHz Carrier frequency lt Output power Phase noise 910MHz MEZ MHz Carrier frequency Output power Phase noise GWINnSTEK 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 noise Caution Be sure to tighten the connectors when connecting the RF cable 59 GWIMSTEK GRF 1300A User Manual and Teaching Materials NOTES 56 GYVINSTEK RF Communication and Signals Experiments NOTES 57 GWIMSTEK GRF 1300A User Manual and Teaching Materials NOTES 58 GYVINSTEK RF Communication and Signals Experime
18. power switch is on the upper left hand side of the device AC 100 2404 Au 56 6047 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 Figure A 3 T Connection i GW INSTEK GRF 1300A RF amp Communication Trainer diagram between z different modules BaseBand er RF Synthesizer FM O 4 The UP and DOWN buttons on the Baseband module can be GWIMSTEK GRF 1300A User Manual and Teaching Materials 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 selected the corresponding LED light will be lit up e The Reset button is used to reset the GRF 1300A When reset the GRF 1300A 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 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 Baseband module Frequency MHz Amp Adi 5 The UP and DOWN buttons on the RF
19. 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 GDeBmo gt steps 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 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 GWINnSTEK RF Communication and Signals Experiments Question Caution MHz MHz The 2 harmonic ratio is 10 dB MHz MHz The 3 harmonic ratio is Table 2
20. the amplitude knob 5MHz frequency deviation test results 94 10 MHz MHz GYVINSTEK 10MHz frequency 40 deviation test dB results RF Communication and Signals Experiments MHz 95 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment 10 Mixer Relevant information Experiment Equipment Experiment goals Experiment principals 96 In experiment 5 and 6 we introduced how the signal is modulated onto a carrier However what are the other processes that need to be performed on the modulated signal before it can be transmitted One thing called a frequency mixer is very import in this process The main function of a frequency mixer is to perform frequency conversion The mixer can convert the RF signal into an intermediate frequency signal or it can do the opposite and convert the intermediate frequency signal into an RF frequency signal in order to transmit or process the carried message respectively The goal of this experiment is to observe how a mixer will shift the frequency spectrum of a signal from a spectrum point of view and to understand the principles of the mixer Item Equipment Quantity Note 1 Spectrum Analyzer 1 GSP 730 2 RF amp Communication 1 CRE 1300A Trainer 3 USB Signal Generator 1 USG LF44 4 RF cable 2 100mm 5 RF cable 1 200mm 6 REF cable 1 800mm 7 Adapter 1 N SMA 1 To understand the working principles of the mixer 2 To observe frequency shift by
21. the picture below J i i S i i yy Ba OOO a mee OOO 6 in OOO jj H f Witt aT Antenna Experiment results 34 GW INSTEK RF Communication and Signals Experiments Question MHz MHz 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 35 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment 2 Measuring a Baseband Waveform Relevant information Experiment goals Experiment principles Experiment contents Experiment steps 36 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 allows students to comprehensively understand how to operate a spectrum analyzer and lays the foundation for subsequent experiments tem Quantiy Note 1 Spectrum analyzer 1 GSP 730 RF amp Communication EE GRE 1300A Trainer RF wire RF wire 800mm Adapter 1 NSMA 1 Measurement and analysis on a basic signal Aw N 2 To understand how to use
22. 00 OO I OOO ws i andpessFilter i o 0 E E H if a tH i bs 9 Spectrum analyzer settings remain unchanged 10 Observe what changes on the spectrum analyzer and record in table 10 3 103 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment results TLI_ 104 1 1 11 Maintain the same connections as used in step 10 Connect the output port in the Base Band module to the FM port in the RF synthesizer FM module with an RF cable Adjust the potentiometer in the bassband so that the audio signal is at a certain level 12 Now set the GSP 730 as follows e Center frequency 2 4GHz e Span SOMHz e Reference level 0dBm e Resolution bandwidth RBW Auto Steps GED aHOOO C Ea sep GDaOoC Es Step10 Hoo gt a Step11 GD a 13 Observe what changes on the spectrum analyzer and record it in table 10 3 14 Covert the AM modulated signal to 2 4 GHz according to the method used to generate an AM modulated signal in experiment 5 Record the result in table 10 3 Slol it ee 4 e O 0 000 AZA i 000 D VY e09 j i USG 1 Frequency shifting with the mixer RF Frequency Test Results GV INSTEK shifting result 880MHz 890MHz 875MHz 10 RF Communication and Signals Experiments MHz MHz Amplitude of each frequency point T0 MHz MEZ Amplitude of each frequency p
23. 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 What is the frequency domain feature of the analyzed signal The output power should not exceed the rated input of the spectrum analyzer otherwise the spectrum analyzer will be damaged When using the RF cable to make a connection be sure to tighten the connector 39 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment 3 Different Baseband Waveforms and their Harmonic Measurement Relevant information Experiment equipment Experiment goals 40 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 measuring 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 wil
24. Deo Ea sp GDeo Ei Step4 oA Step5 5 Record the carrier power Set the deviation of the carrier frequency fm to a deviation A of 100kHz Use the Delta GWINnSTEK RF Communication and Signals Experiments marker function on the spectrum analyzer to measure the A value sep GDoBoooc 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 a Step7 ia 2 m Step8 gDoocoo0 CHA Step9 Record the carrier power Set the deviation carrier frequency fm to a deviation A of 100kHz Use the Delta Marker function on the spectrum analyzer to measure the A value stepo oR ooo C 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 frequency to 910MHz and again measure the power and phase noise corresponding to the frequency Step11 pul S gt 51 GWIMSTEK GRF 1300A User Manual and Teaching Materials sp D0000 El Step13 Record the carrier power Set the deviation carrier frequency fm to a deviation A of 100kHz Use the Delta Marker function on the spectrum analyzer to measure the A value step oboo tD 4 Record the value then calculate the
25. Manual and Teaching Materials NOTES 30 GWINnSTEK An Introduction to Spectrum Analyzers RF COMMUNICATION and SIGNALS EXPERIMENTS 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 Peak Search Main keys for setting Power Measurement Control keys Limit Line for setting Frequcncy RBW T Trace Amplitude Display Autoset Memory GYNnsTeEK cse 720 Numeric keypad RF input terminal 31 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment 1 Basic Operation of a Spectrum Analyzer Relevant information Experiment equipment Experiment goals Experiment principles 32 In addition to the sky oceans and forests there is an invisible intangible inaudible and complex electromagnetic network in our living environment This 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 an
26. O signal port to the RF port will affect the LNA and even radiate through the antenna With a diode ring frequency mixer in particular when an LO signal passes through the LO port and leaks into the RF input port it will transmit out the LO signal through the antenna to create interference in the adjacent channels The leaking power from the RF port to the LO port makes the LO vulnerable to frequency pulling When the LO port leaks to the mixer output port a big LO signal can affect the amplification of the IF signal 101 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment contents Experiment steps 102 1 Observe frequency shift 2 Measure port isolation and conversion gain 3 Use the GRF 1300A to emit a 2 4GHz modulated signal 1 Turn on the GRF 1300A and GSP 730 2 Set up the GRF 1300A e Connect an RF cable from the RF FM port in the synthesizer FM module to the IF In port in the Mixer module e Connect an RF cable from the USG USB signal generator output port to the LO In port in the mixer module e Connect an RF cable from the RF output in the mixer module to the RF port of the spectrum analyzer e Use PC software to set the USG frequency to 1520MHz S ly ast HSol a S 000 Q J O00 E BR O00 D ww of OOO ji ay pia USG 3 Set the spectrum analyzer as follows e Center frequency 2 4 GHz e Span FULL e Reference level 0dBm e R
27. RF amp Communication Trainer GRF 1300A STUDENT BOOK USER MANUAL and TEXT BOOK GW INSTEK PART NO 82RF 1300AMo1 ISO 9001 CERTIFIED MANUFACTURER LU GY INSTEK x 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 able of Contents SAFETY WIN SIR CIO IN Seere EE E conse E T 2 ABOUT TAS BOOK errira ian EE AEE EE ES 5 INTRODUCTION to the GRF 1300A ccccsscssceeccssceesceecesceees 6 PCAC COS NS caie E E E E E 8 Product Specifications and FUNCTION sesrraccemincininninni i eet 8 RS OO TOSTU OS e a A E E E E E E 9 OVERVIEW of the TIME and FREQUENCY DOMAIN seese 16 Observation from a different Perspective cccccccceccssccscceccecceeceeescceeceeeeeeaseeeeeees 16 AN INTRODUCTION to SPECTRUM ANALYZERS 06 24 BroadbDand ROC SIV SF reien no E T ER E E 24 ACCU O a ee E et es E E ec eee ees 25 Resolution Bandwidth Filter s ccctscs
28. 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 1300A_ 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 Line Editing Table shown below Lower Limit Line Editing Table MHz dBm No MHz dBm on 4 4 44 4 J 4 5 D amp amp Gi Ee i Ee i EES L E Li oo amp G Gi on Lo ee ee 8 SS amp amp 5 G G amp Gi ue i Ee i Eae L E Li Bo amp amp Gi 91 GV INSTEK 92 GRF 1300A 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 comma
29. 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 1300A 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 108 GYVINSTEK Fault 2 Fault description Hypothesis Verification 2 FM Fault Simulation Fault 1 Fault description Hypothesis Verification Fault 2 Test for Learning Outcomes 109 GWIMSTEK GRF 1300A User Manual and Teaching Materials Fault description Hypothesis Verification Fault 3 Fault description Hypothesis Verification Fault 4 Fault description Hypothesis 110 GW INSTEK Test for Learning Outcomes Verification 3 AM Fault Simulation Fault 1 Fault description Hypothesis Verification Fault 2 Fault description Hypothesis Verification 111 GWIMSTEK GRF 1300A User Manual and Teaching Materials Fault 3 Fault description Hypothesis Verification Fault 4 Fault description Hypothesis Verification 112
30. age 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 Step 1 gw ON 7 gt EER 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 8 gt a 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 6 T Step13 sepu DoM ooo o 11 Use the DOWN button on the RF Synthesizer 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 Step15 WO FT DOWN Peak Step16 65 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experime
31. alyzers 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 Frequency Start 697 455MHz Center 900 05MHz Stop 90 55MHz RBYW 50kHz Span 5 0MHz Sweep 14sec GWINnSTEK RF Communication and Signals Experiments The Frequency Amplitude and Span keys as well 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 the keypad to control the frequency amplitude and other related settings as the keypad and ame unit keys Experiment contents Experiment steps 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 frequ
32. asurements are channel bandwidth channel spacing and OCBW 1 Measure the ACPR from the FM signal produced by the GRF 1300A 2 Measure the OCBW from the FM signal produced by the GRF 1300A 1 Turn on the GRF 1300A and GSP 730 2 Set up the GRF 1300A 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 83 GWIMSTEK GRF 1300A User Manual and Teaching Materials ACPR measurement 84 laolao Oooo i e ai NH a2 oo mam O00 00o D 6 a O00 S UY j I oce i d 3 Set up the GSP 730 as follows e Center frequency 880MHz e Span LOMHz e Reference level 10dBm e RBW Auto sp Decoo Ea sp Deco MHA se GDacoe B aw J Step4 Adjust the FM frequency deviation to 1MHz 2MHz in total with the amplitude knob Ref 10 0dBm Start 875 0MHz Center 880 0MHz Stop 865 0MHz RBW 100kHz Span 10 0MHz 5 Measure the ACPR and OCBW after these settings are performed Step1 tess Tey on sep GWINnSTEK RF Communication and Signals Experiments OCBW measurement Experiment results Set the bandwidth of the main channel to 2MHz seeps OR Set the main channel space to 5MHz se Bo Bl Set the bandwi
33. changes in the modulation signal Then 0 tAwcosQrt In this formula o is the angular frequency of the carrier wave Aw 71 72 GWIMSTEK GRF 1300A 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 400 u t Uem cos Wet Uem cos Wct mf sin Qt Mo 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 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 fu
34. dth of the 1st adjacent channel 0 8MHz Step5 F2 Set the offset of the 1st adjacent channel to 2MHz Step6 Fs Set the bandwidth of the 24 adjacent channel to 0 5MHz step OE 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 GD ks step al Set the bandwidth of the channel that you will measure to 2MHz step OE 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 1300A Measure the OCBW again and record the results to table 7 2 Record the measurement data in Table 7 2 1 ACPR measurement results 85 GWIMSTEK GRF 1300A User Manual and Teaching Materials IMHz frequency 40 deviation results dB r MHz MHz 2MHz frequency 40 deviation results dB p MHz MHz 2 OCBW measurement results 86 GWINnSTEK RF Communication and Signals Experiments IMHz frequency 40 deviation results dB i MHz MHz 2MHz frequency 40 deviation results dB r MHz MHz ocBW a ee ee ee ee ee es ee ee Questions Describe the definition for ACPR Caution Taking multiple measurements and the getting average value is required for ACPR and OCBW measurements Using the
35. e software installation is complete users can perform a system error check by sending commands to the GRF 1300A using Hyper Terminal 13 GWIMSTEK GRF 1300A User Manual and Teaching Materials Figure A 10 Operation interface for HyperTerminal ai New Connection Enter a name and choose an ican for the connection Connection Description Mame Doo f lor gg HyperTerminal Edit View Call Transfer Help IDN GW INSTEK GRF 1306 SN Connected 0 01 27 Auto detect 9600 8 H 1 14 GW INSTEK Introduction to the GRF 1300A 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 Returns the state open or closed of the number for the currently selected relay corresponding test WAVE 0 The waveform to sine WAVE WAVE 2 number I e B1 0 number l e B3 1 frequency frequency 15 GWIMSTEK GRF 1300A User Manual and Teaching Materials 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 d
36. e wave GW INSTEK RF Communication and Signals Experiments Experiment results Table 3 1 1MHz triangle wave spectrum test results Step9 GD Es After the spectrogram on table 3 3 is drawn measure the harmonic ratio of each harmonic using the following steps stepo Dome step Demo 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 and square waves MHz MHz 43 GWIMSTEK GRF 1300A User Manual and Teaching Materials 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 44 GW INSTEK RF Communication and Signals Experiments 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 3r4 harmonic Harmonic ratio of 10 the 3rd harmonic dB triangle wave 0 MHz MHz Harmonic
37. eases to a certain extent such as when the difference between the RF input level and the LO level is more than 10dB the rate of the IF output slows and the relationship between the RF input and RF output is no longer linear At this point the frequency mixer begins to enter saturation and exhibits GYVINSTEK 10 3 1dB compression point RF Communication and Signals Experiments non linear distortion as shown in Figure 10 3 The figure shows that the conversion compression point is the point in which the IF output power level deviates from the linear ideal by 1dB Obviously the conversion compression point indirectly expresses the extent of the nonlinear distortion of the frequency mixer Fora LNA this 1dB compression point can also be used to represent the linear amplification range for a LNA Pil dBm j ldB Pr Se Pa Saturation i point 1dB compression i point Pr Pr Dynamic Range gt dBm 3 Port isolation The port isolation of the mixer characterizes the balance of the internal circuitry which determines the amount of feedthrough leakage between the mixer and each port Theoretically the ports on a mixer should be strictly isolated but because practical internal mixer circuitry is somewhat unbalanced it will generate signal feedthrough between each port If the isolation between each port of the frequency mixer is low it will directly affect the following aspects The leakage of the L
38. ence between 0dBm and 50dBm Is it 50dB or 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 type Resistance Attenuators 500 R1 R3 _ 900 a 869 55 E 55 m 292 40 292 40 si 178 49 ar 49 7 on aso OOOO ons OOOO eC eS a nT a a OE S En 119 GWIMSTEK GRF 1300A User Manual and Teaching Materials Resistor Values in T type Resistance Attenuators R1 R3 500 T mm 500 a Se f a E a 1 a T C a ee a rps n gg f a 4 40 4900 120 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 25 0 11 0 20
39. ency range then we can set the start and stop frequency range Connect the antenna to the GSP 730 spectrum analyzer to test the radio waves in the environment 1 Connect the antenna to the GSP 730 spectrum analyzer 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 Deooo Ea sep ZED eooe Ei 33 GWIMSTEK GRF 1300A User Manual and Teaching Materials tp GDeooo Ea se GD o ES 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 amplitude of the signal Step5 ep Ea 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 Step6 F2 Set the center frequencies to each of the three frequency points sep GDC Es 6 Testing the wireless signals in the environment is shown in
40. es 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 GW INSTEK Safety Instructions Power Supply WARNING Fuse N WARNING Cleaning the GRF 1300A 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 de
41. escribe 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 Gi ISTE wo A EGGS Trigd i Measure am ISTEK gt r A DBAS Trigd jL Measure Se ne ee ee ne ee ee aS Ue rae ean etree apna OES ee Ree no yee eee ee ee ne ore GN eee ee l Period ee DO DODO DO DO LO o 1 Pered 41 1 886us OG G AE 2 chan of Jz chan off f te pea ia a a cej Vavg Sand oaran SOARE ERRE siaa nnn TERETE dani MERLE l em oo 711 35 Gm i i Ji 51 imi E e T a E sews f J chan E E T E E E E E E N cole chan wet ipo l i t A Eaa ooa i Jea 2 er i i o 1 idth Eoo ee ooo dewith 1b id i l nE I Ha kraai i H 1 495 ars Lr annie teas ae ace a ac ie a te ec ea y 1 p d chan of lz chan off er eee i ee aial a eee E Ut wu x 7a Nt Buty Cycle Buty Cycle Ee oo ee 7 1 49 48 a me Ji 50 07 F e sssssnso Por ee _ Co ee ee ee ee 2 chan aff i z os g mor ii me a We 8 a char of
42. esolution bandwidth Auto sep GDOOOO Ea Step GED a a sp GDeao Ei seu Do Ss 4 Observe the spectrum distribution with the spectrum analyzer Get the spectrum distribution at the time of frequency mixing Measure the magnitude of each spectral line and draw it into GWINSTEK RF Communication and Signals Experiments table 10 1 Peak Step 5 Adjust the frequency of the RF output in the RF Synthesizer FM module Observe the changes on the spectrum analyzer and record it in table 10 1 sero O 7 2 8888 6 Adjust the frequency of the RF output in the RF Synthesizer FM module Observe the changes on the spectrum analyzer and record it in table 10 1 Step7 O 8386 Down 7 Obtain the spectrum and amplitude of each spectral line according to the previous step calculate the conversion gain of the down converted product and calculate the isolation degree in the IF In port Record the experimental results in the table 10 2 8 After completion of the above experimental steps adjust the RF frequency in the RF Synthesizer FM module to 880MHz Then connect the RF output port in the Mixer module to the BPF in port in the Band Pass Filter module with the RF cable Connect the RF cable that was originally connected to the RF output port in the Mixer module to BPF output port and keep the other connected to the input port of the spectrum analyzer S El i oS T S yi S a Oooo O
43. 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 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 GW INSTEK Introduction to the GRF 1300A Aout THIS BOOK This textbook was developed in conjunction with the GRF 1300A 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 N
44. g signal must be outside the of 73 GWIMSTEK GRF 1300A User Manual and Teaching Materials Figure 6 2 GRF 1300A FM principle Experiment contents Experiment steps 74 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 Modulating signals Crystal Phase Loop Voltage Oscillator 1 Measure the FM wave spectrum 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 1 Turn on the GRF 1300A and GSP 730 2 Set the GRF 1300A 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 to the RF input port on the spectrum analyzer with an RF cable ORE 43 00a 0000 ey fs fz oF edt La joo00 0000 ooo 9080 I lanag 0000 3 Set the GSP 730 as follows e Center frequency 880MHz e Span SOMHz e Reference level 0dBm e RBW Auto GWINnSTEK RF Communication and Signals Experiments sep DAO Ei Step2 f son TOOLE Step3 GDeoo El Step4 O A Ea
45. he 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 89 GYVINSTEK Experiment results Question Caution 90 GRF 1300A User Manual and Teaching Materials 4 A connection diagram is shown below C F t 000 m G8 0000 5 A blue tooth device or wireless network card can also be used in the same way to create a signal to measure MHz MHz What are the advantages for a wireless mouse to operate in the 2 4 G bandwidth Use the Peak Hold function on the spectrum analyzer to capture the signal emitted from the wireless mouse It is not easy to dynamically measure the signal GWINSTEK 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 1300A is in a production line environment
46. ipal 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 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
47. is Ae 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 i i ta i i I ii i i ii A ree a L 4 Pa kaanak pad all 1 i Mu A Wy ail ull j ivy hay mi Yi 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 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 17 GWIMSTEK GRF 1300A User Manual and Teaching Materials QS RX WSS a WV Time domain Frequency domain 18 GYVINSTEK Overview of the Time and Frequency Domain NOTES 19 GWIMSTEK GRF 1300A User Manual and Teaching Mate
48. l MHz MHz 300Khz MHz MHz 600kHz MHZ MHz 78 GWINSTEK RF Communication and Signals Experiments Table 6 4 Experimental results Changing the carrier frequency 1MHz MHz MHz Conclusion 3 Changing the carrier frequency Carrier Experimental result frequency 8 75MHz 10 oui MHZ MHz 880MHz 10 T0 MHZ MHz 79 GWIMSTEK GRF 1300A User Manual and Teaching Materials Question 80 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 GWINSTEK RF Communication and Signals Experiments Experiment 7 Using a Spectrum Analyzer in Communication Systems Relevant information Experiment equipment Experiment 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
49. l from the output port on the GRF 1300A to the input terminal on GSP 730 with the RF cable 0000 At ee a J Aad L j 5500000 coo 080 1986 VOLO a Sh 4 Set the GSP 730 as follows e Center frequency 15MHz e Start frequency OkHz e Stop frequency 30MHz Span 30MHz 41 42 GWIMSTEK GRF 1300A User Manual and Teaching Materials e Reference level 0dBm e RBW Auto Step1 f son TOOD EX Step2 moco mE Step3 Doo D Step4 eG 3 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 drawing a simple sketch of the spectrum in table 3 1 sepr C oR 6 sep O ope 7 Select the square wave on the GRF 1300A Baseband module Do the same spectrum measurements that were performed in the previous steps bm e mw ew steps gt HEE Wave Select 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 triangl
50. l 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 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 61 GWIMSTEK GRF 1300A User Manual and Teaching Materials unmodulated state to an AM wave modulated state
51. l thus gain a better understanding of the theory behind the Fourier series tem Quantity Note 1 SP 730 1 GRF I30A 1 GDS204 1 800mm Adapter 1 NSMA 1 Measure the harmonic content that is output from the baseband signal aI 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 GWINnSTEK RF Communication and Signals Experiments Experiment principles Experiment contents Experiment steps Set the waveform on the GRF 1300A 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 introduced 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 1300A by analyzing the spectrum of a simple triangle and square wave signal 1 Turn on the GRF 1300A and the GSP 730 2 Set the GRF 1300A baseband as follows e Waveform triangle e Frequency 1MHz e Turn the input amplitude knob clockwise to the end Step1 oe gt Fells o X Wave Select sep JO gt EEE UP 000 E Step3 Amp Adj 3 Connect the baseband signa
52. 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 1300A 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 81 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment principles Figure 7 1 RF power amplifier input and output Figure 7 2 Definition of ACPR 82 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 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 ou
53. modulating signal frequency to 1MHz Observe the change in the spectrum of the FM wave and record the results in Table 6 3 a Step11 2 gt N l 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 step12 Amp Adj steps 8588 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 GWINnSTEK RF Communication and Signals Experiments Experiment 1 Changing the amplitude of the modulating signal results Table 6 2 Modulatin Experiment result Experimental voltage Results Changing the amplitude of VPP the modulating signal MHz MHz Frequency deviation FM index Vpp 10 70 Mrz MHz Frequency deviation FM index Vpp MHz MHz 77 GWIMSTEK GRF 1300A User Manual and Teaching Materials Frequency deviation FM index Conclusio n 2 Changing the frequency of an FM signal Table 6 3 Modulating Experimental result Experimental frequency results Changing the frequency of 100Khz the FM signa
54. n the GRF 1300A 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 i tp GDoo El steps Daa 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 Gd A 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 DODO Step7 GD ES DOCO 49 GWIMSTEK GRF 1300A User Manual and Teaching Materials Measure the RF phase noise 50 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 frequency Record the results in table 4 2 1 Turn on the GRF 1300A and the GSP 730 2 Set the GRF 1300A RF Synthesizer FM as follows e Carrier frequency 875MHz step gt ERT DOWN 3 Connect the RF FM output port on the GRF 1300A to the input terminal on GSP 730 with the RF cable 0080 agag 0008 0000 oLeLeLe Oooo Ps ue a ee leooe I000 DE coy 4 ho ho a t m e 4 Set the GSP 730 as follows e Center frequency 875MHz e Span IMHz e Reference level 0dBm e RBW Auto default state is 50kHz sp QDeooo tp
55. nction of the first kind There are an infinite number of frequency components in FM waves and they are distributed symmetrically around the center of GWINnSTEK 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 examples 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 1300A 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 modulatin
56. nds 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 settings 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 GWINnSTEK 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
57. nsentecconasatsndiwcsaeactintwendeeernashouaneastensarcebbaateeecenastoeah 25 Dy cH ei 0 pee nee E E ere rere ee E ene rr er eee ee er ere ree 27 video Bandwidth Filter sorier siima rannen A E A 27 RF COMMUNICATION and SIGNALS EXPERIMENTS 06 31 Experiment 1 Basic Operation of a Spectrum AnalyZer sssssessesssseesessesessesersersee 32 Experiment 2 Measuring a Baseband Waveform ccccsccceeccecceeceeeceeeeeeeeceaseeeeaees 36 Experiment 3 Different Baseband Waveforms and their Harmonic Measurement 40 Experiment 4 Measurement of the RF Carries ccccssccssceccesccesceecceseeesensceesensees 47 Experiment 5 AM Signal Measurement cccccsscnsscoecsscoesssscesscosssnscessceessascenss 60 Experiment 6 FM signal Measurement ccssccsccsecescesccsccescescescescesseescescessesceeses 70 Experiment 7 Using a Spectrum Analyzer in Communication Systems 064 8 Experiment 8 Measurement of communication Products ssssssssssessessesersersesseses 88 Experiment 9 Production Line Applications cccccccscsscceceeceeceeceeceececceccssessesees 9 PAPET E TO NET E T E E E EE 96 TEST for LEARNING OUTCOMES 2 cccceeccsccessceeseesscesseeeeens 108 APPENDIX oeer E E E E EEE S E E E 117 dBm Conversion TADIS sepini geno ansien REEE 117 The relationship between dB and dBC s o ssnssssessssssesesessssrsrsesesessesesesesesseseseseseo 118 Resistor Values in n type Resistance Atten
58. nt 1 Changing modulating voltage results Table 5 4 Modulating Experiment results Experiment voltage results Changing the l modulating Vpp voltage 0 70 MHz MHz Carrier power Modulation index Lower sideband poweri o Vpp 10 70 MHz MHz Carrier power _ Modulation index Lower sideband power Vpp 10 66 GW INSTEK RF Communication and Signals Experiments Table 5 5 Experiment results Changing the modulating signal frequency Modulation index Lower sideband power Conclusion 2 Changing the modulating signal frequency Modulating Experiment results frequency 100kHz 10 70 MHz O MHZ Carrier power 300Khz MHz MHz 67 GWIMSTEK GRF 1300A User Manual and Teaching Materials 600kHz MHz MHz Carrier power lt 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 MHz MHz 68 GWINnSTEK RF Communication and Signals Experiments 8 78MHz 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
59. nts NOTES 59 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment 5 AM Signal Measurement Relevant information Experiment equipment Experiment goals Experiment principles 60 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 different 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 Spec
60. oint 10 O MEZ MEZ Amplitude of each frequency point 2 Conversion gain for the down converted product and the isolation degree of the IF In port 105 GWIMSTEK GRF 1300A User Manual and Teaching Materials Table 10 2 Conversion gain Calculation of gain and isolation MHz MHz Gain IF In port 10 isolation 0 MHZ MHz Isolation 3 2 4GHz modulated signal Table 10 3 Unmodulated 10 signal 2 4GHz 8 0 modulated 10 signal 70 MHz MHz 106 GWINnSTEK RF Communication and Signals Experiments FM modulated signal O MHz MHz AM modulated signal MHz MHz Questions 1 What are the characteristics of a bandpass filter 2 Why are there 5 frequency points in the output spectrum of the frequency mixer 107 GWIMSTEK GRF 1300A User Manual and Teaching Materials est 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 understanding
61. on of trigonometric functions the multiplication of the inputs results in the addition and difference of fe and fi le fi f feand fi ft fc where f is called the intermediate frequency The mixing frequency signal with the carrier frequency f is called the intermediate frequency signal ui t fut fe f fel e e fiy fe ur t ft Bandpass filter Say the modulated input signal Us t ig Us t Vscos ct the local oscillation signal Z is u t Vicos t then the product becomes ui t VsVi Ccos ct COS at ae cos c WL t COS z Wc t Passing through a band pass filter and removing one of the frequency components Or WL Wc completes the frequency conversion Generally the new carrier frequency is called the IF signal The spectrum of the calculated result above is shown in the 97 98 GWIMSTEK GRF 1300A User Manual and Teaching Materials diagram below Down Up conversion conversion CL Mc CL Mc OL We can see from the spectrum shift in the chart above that the mixing frequency signal is the addition and subtraction of the input signal and the LO signal As the frequency mixing device is generally a non linear device it is obvious that a non linear combination of frequency distortion and interference will inevitably occur in the mixing process The harmonic components of the LO signal and the input signal will also be input into the frequency mi
62. otes section in these missing areas GWIMSTEK GRF 1300A User Manual and Teaching Materials NTRODUCTION to the GRF 1300A The GRF 1300A is a well designed training kit capable of producing a 3MHz baseband signal and a carrier signal up to 900MHz The GRF 1300A is also able to perform 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 1300A 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
63. ove 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 Ps is the measured sideband power Lif Pssp Po log B 2 5 where B 1 2RBW RBW is the resolution bandwidth Po SSB Fa 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 GW INSTEK RF Communication and Signals Experiments Experiment 1 contents 2 3 Experiment steps Measure the RF 1 signal spectrum and harmonic distortion 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 1300A and GSP 730 Leave the GRF 1300A in its power on state Connect the RF FM output port o
64. pter 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 GWINnSTEK 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 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
65. ratio of the 5th harmonic dB triangle wave MHz MHz 45 GWIMSTEK GRF 1300A User Manual and Teaching Materials Harmonic ratio of 10 the 2 harmonic dB Square wave 0 MHz MHz Harmonic ratio of the 3 harmonic dB Square wave MHz MHz 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 46 GWINSTEK RF Communication and Signals Experiments Experiment 4 Measurement of the RF Carrier Relevant information Experiment equipment Experiment goals Experiment principles 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
66. requency mixers such as transistors FETs or integrated analog multipliers the conversion gain is frequency gain gt 1 In measuring the conversion gain Gc the LO drive power must be a fixed power level For example for a diode ring mixer with a 500 input output impedance the LO standard power level is 7dBm For the integrated analog multiplier MC1596 the LO standard power level is 20dBm When measuring and applying the frequency mixer it should be noted that impedance matching should be used with the three ports of the frequency mixer When the RF port of the frequency mixer passes through image rejection filter and is connected to LNA the input impedance in the RF port of frequency mixer must match the output impedance of its filter to ensure the performance of the filter Generally the output impedance of the filter is 509 Similarly the output impedance of the IF port of the frequency mixer should match the input impedance of the IF filter Generally the impedance of an IF filter with a frequency lower than 100MHz is greater than 50Q 2 1dB compression point The Compression point is used to denote the non linear distortion of a frequency mixer For a signal with small RF the frequency mixer is a linear network When the RF input level is much smaller than the LO level the frequency mixer operates linearly In other words the RF output increases linearly with an increase in the RF input level However when the RF input incr
67. rials NOTES 20 GYVINSTEK Overview of the Time and Frequency Domain NOTES 21 GWIMSTEK GRF 1300A User Manual and Teaching Materials NOTES 22 GYVINSTEK Overview of the Time and Frequency Domain NOTES 23 GWIMSTEK GRF 1300A User Manual and Teaching Materials An INTRODUCTION to SPECTRUM ANALYZERS 24 Broadband Receiver 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 The principal function of a spectrum analyzer is to convert the input signal frequency down 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 freq
68. sB__ 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 122
69. scope can be used to detect determine the status of the circuitry at these test points Figure A 7 Circuit location of each test point O Tp Modulation CPU 8 Install the GRF 1300A driver onto the PC e Connect the GRF 1300A 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 12 GW INSTEK Introduction to the GRF 1300A Figure A 8 Hardware Installation Software installation A The software you are installing for this hardware USB Communications Port has not passed Windows Logo testing to very its compatibility with Windows sP 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 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 procedure is Completing the Found New complete Hardware Wizard The wizard has finished installing the software for F USE Communications Port Click Finish to close the wizard lt Back Cancel e After th
70. sequence stages The Ap and Aq terms are useful IF terms and should be received by the receiver normally The Am and An components are the third order intermodulation frequency components and they also contribute to channel interference It is difficult to use filters to filter out the third order intermodulation interference The most effective means of reducing third order interference is by designing and producing a mixing device with good linearity Integrated mixing devices usually express the level of third order intermodulation interference using the IP3 point third order intermodulation intercept point A large IP3 value indicates a mixer with good linearity Circuit design that minimizes the amplitude of the RF signal input so that the mixer operates more linearly can also reduce third order intermodulation products 2 The main parameters of the frequency mixer The main technical indicators in the frequency mixer include conversion gain 1dB compression point port isolation and so on 1 Conversion gain The ratio of RF input power level to the output signal power level is called conversion gain Ge Le 99 GV INSTEK 100 GRF 1300A User Manual and Teaching Materials Fi Ge 10 le 5P R In the formula both the RF input power P and IF output power use dBm as the unit There exists conversion loss when the conversion gain is lt 1 therefore for passive diodes which is expressed by Lc While for active f
71. tergent 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 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 GWIMSTEK GRF 1300A User Manual and Teaching Materials Disposal Do not dispose this device as unsorted munic
72. terminal what will happen and why 69 GWIMSTEK GRF 1300A 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 70 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 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 1300A 2 100mm 1 800mm Ada
73. the GRF 1300A system to output a baseband signal Set the GRF 1300A 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 1300A and the GSP 730 2 Set the GRF 1300A baseband as follows e Waveform Sine wave e Frequency 1MHz e Turn the amplitude knob clockwise to its end Step eo FT gt A Wave Select GWINnSTEK RF Communication and Signals Experiments Step2 P a 6 HE Step3 Amp Adj 3 Connect the baseband signal from the output port of the GRF 1300A to the input terminal of the GSP 730 using the RF wire 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 MHz ep Deooo E 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 Step2 Deo Ey sep Deo El sea Dooc 2 Ea Step5 aw Ta 5 Utilize the Marker function on the spectrum analyzer to determine the harmonic ratio and draw the spectrum in Table 2 1 Peak Step6 37 GWIMSTEK GRF 1300A User Manual and Teaching Materials Experiment results 38 After
74. tput 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 GWINnSTEK 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 have 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 me
75. trum analyzer 1 GSP 730 2 RE amp Communication Trainer 1 GRF 1300A 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 GWINnSTEK 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 frequency 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 signa
76. uators ssssssesssseserseseesrsersrsesersrsessese 119 Resistor Values in T type Resistance AttenuatorS ssssssssssesersesersrsersrseserseseseese 120 Modulation Index and Sideband Amplitude Comparison Table cccseceeeeeeees 121 Declaration Of COM ONG N y cossos E EAE 122 GWIMSTEK GRF 1300A User Manual and Teaching Materials SAFETY INSTRUCTIONS This chapter contains important safety instructions that should be followed when operating and storing the GRF 1300A Read the following before any operation to ensure your safety and to keep the GRF 1300A 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 1300A 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 discharg
77. uency 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 GWINSTEK An Introduction to Spectrum Analyzers 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 instructed 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
78. xer as well therefore the output will have the positive and negative components for each harmonic In a wireless transceiver circuit the front end small signal low noise amplifier LNA and the IF amplifier IFA has far less non linear frequency distortion than that produced by the frequency mixer Therefore the combined non linear distortion and frequency interference in the wireless receiver circuit is mainly generated by the frequency mixer circuit The non linear characteristics of the frequency mixer for engineering is commonly expressed by the following expansion formula p 3 1 do diu d2u dzu In the formula u is the total signal that is added to the input end of the frequency mixer Say the composition of u is uU U1 COS Mil U2 COS M2l U3 Cos W3l GW INSTEK RF Communication and Signals Experiments Substituting U i o Ai uicos wit U2 COS 2t U3 COS 3t A u1 cos 2 1 u2 cos 2 2 3 cos 203 A3 ur cos 3 u cos 3 2 u3 cos 303 P cos 3 1 t Aqcos 3 2 t Amcos a 3 2 1 2 t Ancos 3 1 2 2 t Axcos ka 3 rai s 2 t Where the AO term is the DC component items the Al term is the fundamental term while the A2 term and the A3 term are the 2nd and 3rd order harmonics respectively Higher harmonic components have been ignored These frequency components are produced after the mixer and are filtered out with a bandpass filter They do not affect any sub

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