1、RF Seminar,RF Source Basics,Title of Presentation 7/27/2004,Page 2,Agenda,Types of sources CW Swept Signal Generator Block Diagrams Applications Specifications,Title of Presentation 7/27/2004,Page 3,Sources Generate Sine Waves,Voltage,Time,Voltage,Frequency,This is the ideal output: most specs deal
2、with deviations from the ideal and adding modulation to a sine wave,RF,Microwave,Millimeter,20-50 GHz,300 GHz,3-6 GHz,Spectrum Analyzer,Oscilloscope,Title of Presentation 7/27/2004,Page 4,Types of Sources,CW generates a single frequency, fixed sine wave Swept sweeps over a range of frequencies may b
3、e phase continuous Signal Generator adds modulation produces “real world” signal,Title of Presentation 7/27/2004,Page 5,Agenda,Types of sources CW Swept Signal Generator Block Diagrams Applications Specifications,Title of Presentation 7/27/2004,Page 6,CW Source Specifications .Frequency,Voltage,Freq
4、uency,Uncertainty,Range: Range of frequencies covered by the source Resolution: Smallest frequency increment. Accuracy: How accurately can the source frequency be set.,EXAMPLEAccuracy = = CW frequency = 1 GHz= aging rate = 0.152 ppm/year= time since last calibrated = 1 year,*,*,Title of Presentation
5、 7/27/2004,Page 7,CW Source Specifications .Amplitude,DUT,Source protected from accidental transmission from DUT,Voltage,Frequency,How accurate is this number?,What is P out?,What is P out?,max,min,Range (-136dBm to +13dBm) Accuracy (+/- 0.5dB) Resolution (0.02dB) Switching Speed (25ms) Reverse Powe
6、r Protection,Title of Presentation 7/27/2004,Page 8,Phase Noise Residual FM Spurious,CW Source Specifications .Spectral Purity,non-harmonic spur 65dBc,harmonic spur 30dBc,CW output,Residual FM is the integrated phase noise over 300 Hz - 3 kHz BW,phase noise,0.5 f0 f0 2f0,sub-harmonics,Title of Prese
7、ntation 7/27/2004,Page 9,CW Source Specifications . Spectral Purity: Phase Noise,CW output,frequency,Power Spectral Density,measured as dBc/Hz,Ch1 PM PSD,1k,10k,100k,TRACE A:,A Marker,10 000 Hz,75 dBc/Hz,-125 dBc/Hz,LogMag,5 dBc/div,-105 dBc/Hz,Title of Presentation 7/27/2004,Page 10,RF CW Block Dia
8、gram,Reference Oscillator,f,VCO,Phase Detector,Frac-N,divide by X,ALC Modulator,ALC Driver,ALC Detector,Output Attenuator,ALC = automatic level control,Reference Section,Synthesizer Section,Output Section,Title of Presentation 7/27/2004,Page 11,RF CW Block Diagram Reference Section,f,Phase Detector,
9、Optional External Reference Input,Reference Oscillator (TCXO or OCXO),TCXO,OCXO,Aging Rate,+/- 2ppm/year,+/- 0.1 ppm /year,Temp.,+/- 1ppm,+/- 0.01 ppm,Line Voltage,+/- 0.5ppm,+/- 0.001 ppm,to synthesizer section,divide by X,Title of Presentation 7/27/2004,Page 12,RF CW Block Diagram Synthesizer Sect
10、ion,f,VCO,Phase Detector,Frac-N,from reference section,to output section,X 2,multiplier,Front panel control,5MHz,465.5 MHz,N = 93.1,931 MHz,5MHz,.produces accurate, clean signals,Title of Presentation 7/27/2004,Page 13,RF CW Block Diagram Synthesizer Section,reference oscillator,phase noise of sourc
11、e,VCO noise,phase detector noise,broadband noise floor,20logN,phase-locked-loop (PLL) bandwidth selected for optimum noise performance,PLL / Fractional - N .suppresses phase noise,noise,Title of Presentation 7/27/2004,Page 14,RF CW Block Diagram Output Section,ALC = automatic level control,ALC Modul
12、ator,ALC Driver,ALC Detector,Output Attenuator,from synthesizer section,source output,ALC maintains output power by adding/subtracting power as needed Output Attenuator mechanical or electronic provides attentuation to achieve wide output range (e.g. -136dBm to +13dBm),Title of Presentation 7/27/200
13、4,Page 15,mWave CW Block Diagram,ALC Detector,Sampler,Reference Section,Synthesizer Section,Output Section,Ref Osc,f,VCO,Phase Det,Frac N,by X,f,VCO,Phase Detector,Frac-N,f,Phase Detector,Tuning Coils,YIG Oscillator,Title of Presentation 7/27/2004,Page 16,Applications & Critical Specifications,Local
14、 Oscillator phase noise frequency accuracy Amplifier Distortion spurious TOI (for system) Receiver Testing Spuriousspuriouslevel accuracy,Title of Presentation 7/27/2004,Page 17,Applications & Critical Specifications As a Local Oscillator,poor phase noise spreads energy into adjacent channels,poor f
15、requency accuracy will cause transmitter to be at the wrong frequency,DUT,Title of Presentation 7/27/2004,Page 18,Applications & Critical Specifications Amplifier Testing,f2,f1,fU = 2f2 - f1,fL = 2f1 - f2,spurious signals from source can corrupt measurement,frequency,amplitude,test system third orde
16、r products will also fall here,Intermodulation Distortion,Title of Presentation 7/27/2004,Page 19,Applications & Critical Specifications Receiver Testing,Receiver Selectivity,Title of Presentation 7/27/2004,Page 20,Agilent Families of CW Generators,RF,Microwave,Agilent 8664/65 family100 MHz - 6 GHzU
17、nder $50KLow out channel noiseAM/FM/Pulse.,Agilent 8662/63 family100 KHz - 2.5 GHzUnder $70KLow in channel noiseAM/FM/Phase/Pulse,Agilent 83711/12B family10 MHz - 20 GHzUnder $30KCW only,Title of Presentation 7/27/2004,Page 21,Agenda,Types of sources CW Swept Signal Generator Block Diagrams Applicat
18、ions Specifications,Title of Presentation 7/27/2004,Page 22,Sweeper Specifications .Frequency,ramp sweep accuracy sweep time resolution,step sweep accuracy number of points switching time,time,frequency,f2,t2,t1,f1,t4,t3,t1,t2,f4,f3,f1,f2,frequency,Title of Presentation 7/27/2004,Page 23,Sweeper Spe
19、cifications .Amplitude,Frequency Sweep Level Accuracy Flatness Source Match (SWR) Power Sweep Power Sweep Range Power Slope Range Source Match (SWR),Title of Presentation 7/27/2004,Page 24,Applications & Critical Specifications,Frequency Response Frequency Accuracy Output Power (Level) Accuracy Flat
20、ness Speed residual FM Amplifier Compression Power Range,Title of Presentation 7/27/2004,Page 25,Applications & Critical Specifications Frequency Response Testing,LO,Sweeper Input,Frequency Accuracy Output Power (Level) Accuracy Flatness Speed residual FM,Title of Presentation 7/27/2004,Page 26,Appl
21、ications & Critical Specifications Frequency Response Testing,Who Cares About Accuracy?,Title of Presentation 7/27/2004,Page 27,Applications & Critical Specifications Amplifier Compression,The 1 dB compression point is a common amplifier specification used to identify the linear operating range of a
22、n amplifier. Power sweep is available on some Agilent sources.,Power Range,Title of Presentation 7/27/2004,Page 28,Synthesized Sweep Generators,83750 Series $26-35k Step/Analog sweep AM/FM/Phase modulation 10MHz to 20GHz up to 110GHz with 83550 seriesmodules and amplifier8360L Series $35-50k Step/An
23、alog sweep 8510/8757 Compatibility 10MHz to 50GHz up to 110GHz with 83550 seriesmodules,Title of Presentation 7/27/2004,Page 29,Agenda,Types of sources CW Swept Signal Generator Block Diagrams Applications Specifications,Title of Presentation 7/27/2004,Page 30,Signal Generators,Calibrated modulation
24、 Analog (AM, FM, PM, Pulse) Digital (I-Q) Format Specific(TDMA,CDMA, etc.),Title of Presentation 7/27/2004,Page 31,Modulation .Where the information resides,AM, Pulse,FM,PM,q,V= A(t) sin (t),p,V= A(t) sin2 f(t) + (t),f,Title of Presentation 7/27/2004,Page 32,Modulation: Analog Amplitude Modulation,I
25、mportant Signal Generator Specs for Amplitude Modulation,Voltage,Time,Carrier,Modulation,Modulation frequency Linear AM Log AM Depth of modulation (Mod Index),Title of Presentation 7/27/2004,Page 33,Modulation: Analog Frequency Modulation,Voltage,Time,V= A sin2 f t + m(t),p,c,b,F /F,dev,mod,b = D,Fr
26、equency Deviation Modulation Frequency dcFM Accuracy Resolution,Title of Presentation 7/27/2004,Page 34,Modulation: Analog Phase Modulation,b = Df,peak,Voltage,Time,c,b,Title of Presentation 7/27/2004,Page 35,Modulation: Analog Pulse Modulation,Time,Pulse,On/Off ratio,Rise,time,Rate=1/T,T,Width,Powe
27、r,t,1/t,1/T,Power,Title of Presentation 7/27/2004,Page 36,Digital Modulation .signal characteristics to modify,AmplitudeFrequency Phase,Both Amplitude and Phase,Title of Presentation 7/27/2004,Page 37,Digital Modulation Polar Display: Magnitude & Phase Represented Together,Magnitude is an absolute v
28、alue Phase is relative to a reference signal,Phase,Mag,0 deg,Title of Presentation 7/27/2004,Page 38,Digital Modulation Signal Changes or Modifications,Phase,Mag,0 deg,Magnitude Change,Phase,0 deg,Phase Change,Frequency Change,Both Change,0 deg,0 deg,Title of Presentation 7/27/2004,Page 39,Digital M
29、odulation .Binary Phase Shift Keying (BPSK),f,(t) =,p,f,Title of Presentation 7/27/2004,Page 40,Digital Modulation BPSK IQ Diagram,I,Q,0,1,One Bit Per Symbol Symbol Rate = Bit Rate,Title of Presentation 7/27/2004,Page 41,Digital Modulation .Quadrature Phase Shift Keying (QPSK),p,f,Title of Presentat
30、ion 7/27/2004,Page 42,Digital Modulation QPSK IQ Diagram,I,Q,00,01,10,11,Title of Presentation 7/27/2004,Page 43,Digital Modulation p/4 DQPSK IQ Diagram,I,Q,Title of Presentation 7/27/2004,Page 44,Digital Modulation Modulation Accuracy,Title of Presentation 7/27/2004,Page 45,Digital Signal Generator
31、 Block Diagram,reference section (supplies timing),to output section,Title of Presentation 7/27/2004,Page 46,Digital Modulation PSK Implementation: IQ Method,p/2,Carrier,Good Interface with Digital Signals and Circuits Can be Implemented with Simple Circuits Can be Modified for Bandwidth Efficiency,
32、I:,Q:,Title of Presentation 7/27/2004,Page 47,Digital Signal Generator Block Diagram IQ Modulator,p/2,Ext I,Ext Q,from synthesizer section,to output section,Q from Baseband Generator,I from Baseband Generator,Title of Presentation 7/27/2004,Page 48,Digital Signal Generator Block Diagram Baseband Gen
33、erator,Analog Reconstruction Filters,Title of Presentation 7/27/2004,Page 49,Digital Signal Generator Format Specific Digital Signals,NADC (TDMA IS-54),Parameter,Specification,Access Method,TDMA/FDD,Modulation,p/4 DQPSK,Channel Bandwidth,30 kHz,Reverse Channel Frequency Band,824 - 849 MHz,Forward Ch
34、annel Frequency Band,869 - 894 MHz,Filtering,0.35 RRC,Title of Presentation 7/27/2004,Page 50,Digital Signal Generator Access and Framing,one frame = 1944 bits (972 symbols) = 40ms; 25frames/sec,slot 1 slot 2 slot 3 slot 4 slot 5 slot 6,324 bit (162 symbols) = 6.667ms,G R Data Sync Data SACCH CDVCC
35、Data6 6 16 28 122 12 12 122,Mobile to Base Station,Title of Presentation 7/27/2004,Page 51,Applications and Critical Specifications Analog and Digital,Receiver Sensitivity frequency accuracy level accuracy error vector magnitude Receiver Selectivity phase noise spurious spectral accuracy Spectral Re
36、growth ACP performance,Title of Presentation 7/27/2004,Page 52,Applications and Critical Specifications Receiver Sensitivity,Frequency Accuracy,Title of Presentation 7/27/2004,Page 53,Applications and Critical Specifications Receiver Sensitivity,Customer is testing a -110 dB sensitivity pager:,Power
37、 Out,-110 dB specification,Case 1: Source has +/-5 dB of output power accuracy at -100 to -120 dBm output power.,Set source to -115 dBm,Actual output power= -114 dBm,X,X,X,X,X,O,Case 2: Source has +/-1 dB of output power accuracy at -100 to -120 dBm output power.,Power Out,-110 dB specification,Set
38、source to -111 dBm,Actual output power= -112 dBm,X,X,O,O,O,O,X= Failed unit,O=Passed unit,Frequency,Frequency,Level Accuracy,Title of Presentation 7/27/2004,Page 54,Applications and Critical Specifications Receiver Sensitivity,Error Vector Magnitude (EVM),Title of Presentation 7/27/2004,Page 55,Appl
39、ications and Critical Specifications Receiver Selectivity,Phase Noise Spurious,Title of Presentation 7/27/2004,Page 56,Applications and Critical Specifications Receiver Selectivity,Spectral Accuracy: EVM ACP,Title of Presentation 7/27/2004,Page 57,Applications and Critical Specifications Spectral Re
40、growth,Input from signal generator,Output from amplifier,ACP Performance,Title of Presentation 7/27/2004,Page 58,Agilent Families of Signal Generators,RF,Microwave,Agilent 8647/48 family9 KHz - 4 GHz5 - $10KAM/FM/PhasePaging, SMR, Cordless,Agilent ESG family250 KHz - 4 GHz7 - $15KAM/FM/Phase/PulseDigital/I-Q ModGSM,CDMA,DECT.,Agilent 8360B family 10 MHz - 50 GHz30 - $60KAM/FM/Pulse 110 GHz with ext. module,Agilent 83730 family10 MHz - 20 GHz25 - $35KAM/FM/Pulse,
