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Agenda

Agenda. Types of sources CW Swept Signal Generator Block Diagrams Applications Specifications. Sources Generate Sine Waves. Voltage. Time. Frequency. Voltage. Spectrum Analyzer. Oscilloscope.

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Agenda

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  1. Agenda • Types of sources • CW • Swept • Signal Generator • Block Diagrams • Applications • Specifications Source Basics

  2. Sources Generate Sine Waves Voltage Time Frequency Voltage Spectrum Analyzer Oscilloscope This is the ideal output: most specs deal with deviations from the ideal and adding modulation to a sine wave Millimeter RF Microwave 3-6 GHz 20-50 GHz 300 GHz Source Basics

  3. Types of Sources • CW • generates a single frequency, fixed sine wave • Swept • sweeps over a range of frequencies • may be phase continuous • Signal Generator • adds modulation • produces “real world” signal Source Basics

  4. Types of sources • CW • Swept • Signal Generator • Block Diagrams • Applications • Specifications Agenda Source Basics

  5. CW Source Specifications ...Frequency t + + t f _ _ cal aging CW f CW t aging t cal Accuracy = 152 Hz • Range: Range of frequencies covered by the source • Resolution: Smallest frequency increment. • Accuracy: How accurately can the source frequency be set. EXAMPLE Accuracy = = CW frequency = 1 GHz = aging rate = 0.152 ppm/year = time since last calibrated = 1 year * * Uncertainty Voltage Frequency Source Basics

  6. CW Source Specifications ...Amplitude • Range (-136dBm to +13dBm) • Accuracy (+/- 0.5dB) • Resolution (0.02dB) • Switching Speed (25ms) • Reverse Power Protection Source protected from accidental transmission from DUT What is P out? How accurate is this number? max DUT Voltage min What is P out? Frequency Source Basics

  7. Phase Noise Residual FM Spurious CW Source Specifications ...Spectral Purity CW output Residual FM is the integrated phase noise over 300 Hz - 3 kHz BW harmonic spur ~30dBc phase noise non-harmonic spur ~65dBc sub-harmonics 0.5 f0 f02f0 Source Basics

  8. CW Source Specifications ... Spectral Purity: Phase Noise CW output measured as dBc/Hz Power Spectral Density frequency Ch1 PM PSD TRACE A: A Marker 10 000 Hz 75 dBc/Hz LogMag 5 dBc/div -105 dBc/Hz -125 dBc/Hz 1k 10k 100k Source Basics

  9. RF CW Block Diagram Synthesizer Section Frac-N Output Section Output Attenuator ALC Modulator f Phase Detector VCO ALC Driver divide by X Reference Oscillator ALC Detector Reference Section ALC = automatic level control Source Basics

  10. RF CW Block Diagram Reference Section divide by X 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 f Phase Detector Optional External Reference Input Reference Oscillator (TCXO or OCXO) Source Basics

  11. RF CW Block Diagram Synthesizer Section ...produces accurate, clean signals N = 93.1 Front panel control Frac-N 5MHz to output section f X 2 Phase Detector 931 MHz VCO multiplier 5MHz 465.5 MHz from reference section Source Basics

  12. RF CW Block Diagram Synthesizer Section frequency PLL / Fractional - N ...suppresses phase noise phase noise of source phase-locked-loop (PLL) bandwidth selected for optimum noise performance noise reference oscillator phase detector noise 20logN broadband noise floor VCO noise Source Basics

  13. RF CW Block Diagram Output Section Output Attenuator ALC Modulator from synthesizer section source output ALC Driver ALC Detector • 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) ALC = automatic level control Source Basics

  14. mWave CW Block Diagram Output Attenuator ALC Modulator ALC Driver Reference Section Frac N Phase Det f VCO Sampler by X Ref Osc YIG Oscillator f Phase Detector Tuning Coils Frac-N Synthesizer Section ALC Detector f Phase Detector Output Section VCO Source Basics

  15. Applications & Critical Specifications • Local Oscillator • phase noise • frequency accuracy • Amplifier Distortion • spurious • TOI (for system) • Receiver Testing • Spurious • spurious • level accuracy Source Basics

  16. Applications & Critical Specifications As a Local Oscillator IF signal transmitter output DUT poor phase noise spreads energy into adjacent channels poor frequency accuracy will cause transmitter to be at the wrong frequency Source Basics

  17. Applications & Critical Specifications Amplifier Testing f1 DUT output RF f2 isolator Intermodulation Distortion f1 f2 test system third order products will also fall here spurious signals from source can corrupt measurement amplitude fL = 2f1 - f2 fU = 2f2 - f1 frequency Source Basics

  18. Applications & Critical Specifications Receiver Testing in-channel signal (modulated signal) IF signal out-of-channel signal (CW or modulated signal) DUT source output IF Rejection Curve spur from source and/or high levels of phase noise can cause a good receiver to fail Level (dBm) Frequency Receiver Selectivity Source Basics

  19. Agilent Families of CW Generators RF Agilent 8662/63 family • 100 KHz - 2.5 GHz • Low in channel noise • AM/FM/Phase/Pulse Agilent 8664/65 family • 100 MHz - 6 GHz • Low out channel noise • AM/FM/Pulse. Microwave Agilent 83711/12B family • 10 MHz - 20 GHz • CW only Source Basics

  20. Agenda • Types of sources • CW • Swept • Signal Generator • Block Diagrams • Applications • Specifications Source Basics

  21. Sweeper Specifications ...Frequency • ramp sweep • accuracy • sweep time • resolution f2 frequency f1 t2 t1 time • step sweep • accuracy • number of points • switching time f4 f3 frequency f2 f1 t1 t2 t3 t4 Source Basics

  22. Sweeper Specifications ...Amplitude level accuracy spec power flatness spec f1 f2 frequency } P2 power sweep range power P1 t1 t2 Frequency Sweep • Level Accuracy • Flatness • Source Match (SWR)Power Sweep • Power Sweep Range • Power Slope Range • Source Match (SWR) Source Basics

  23. Applications & Critical Specifications • Frequency Response • Frequency Accuracy • Output Power (Level) Accuracy • Flatness • Speed • residual FM • Amplifier Compression • Power Range Source Basics

  24. Applications & Critical Specifications Frequency Response Testing Sweeper Input • Frequency Accuracy • Output Power (Level) Accuracy • Flatness • Speed • residual FM LO Source Basics

  25. Applications & Critical Specifications Frequency Response Testing Log Mag 5.0 dB/ Ref -15.00 dB 1:Transmission BW: 429.600 MHz CF: 2405.782 MHz 5 dB Q: 5.60 Loss: -0.84 dB 1 0 -5 3 5 6 -10 Ch1 -20 -25 -30 1 -35 Abs Center 2 450.212 MHz Span 1 099.577 MHz Who Cares About Accuracy? Source Basics

  26. Applications & Critical Specifications Amplifier Compression 1 dB compression point Power Out Power In • Power Range The 1 dB compression point is a common amplifier specification used to identify the linear operating range of an amplifier. Power sweep is available on some Agilent sources. Source Basics

  27. Synthesized Sweep Generators • Agilent 83750 Series • Step/Analog sweep • AM/FM/Phase modulation • 10MHz to 20GHz • up to 110GHz with 83550 series • modules and amplifier • Agilent 8360L Series • Step/Analog sweep • 8510/8757 Compatibility • 10MHz to 50GHz • up to 110GHz with 83550 series modules Source Basics

  28. Agenda • Types of sources • CW • Swept • Signal Generator • Block Diagrams • Applications • Specifications Source Basics

  29. Signal Generators • Calibrated modulation • Analog (AM, FM, PM, Pulse) • Digital (I-Q) • Format Specific(TDMA,CDMA, etc.) Source Basics

  30. Modulation ...Where the information resides p f V= A(t) sin[2 f(t) + (t)] AM, Pulse PM FM V= A(t) sin[ (t)] q Source Basics

  31. Modulation: Analog Amplitude Modulation Carrier Important Signal Generator Specs for Amplitude Modulation Voltage Time • Modulation frequency • Linear AM • Log AM • Depth of modulation (Mod Index) Modulation Source Basics

  32. Modulation: Analog Frequency Modulation F /F Important Signal Generator Specs for Frequency Modulation b = D dev mod p b V= A sin[2 f t + m(t)] c • Frequency Deviation • Modulation Frequency • dcFM • Accuracy • Resolution Voltage Time Source Basics

  33. Modulation: Analog Phase Modulation V= A sin[2 p f t + m(t)] Important Signal Generator Specs for Phase Modulation • Phase deviation • Rates • Accuracy • Resolution b c b = Df peak Voltage Time Source Basics

  34. Modulation: Analog Pulse Modulation Important Signal Generator Specs for Pulse Modulation • Pulse width • Pulse period • On/Off ratio • Rise time T Rate=1/T Rise time Power On/Off ratio t Time Pulse Width 1/T 1/t Power Source Basics

  35. Digital Modulation ...signal characteristics to modify Amplitude Frequency Phase Both Amplitude and Phase Source Basics

  36. Digital Modulation Polar Display: Magnitude & Phase Represented Together Mag Phase 0 deg • Magnitude is an absolute value • Phase is relative to a reference signal Source Basics

  37. Digital Modulation Signal Changes or Modifications Mag Phase Phase 0 deg 0 deg Magnitude Change Phase Change 0 deg 0 deg Both Change Frequency Change Source Basics

  38. Digital Modulation ...Binary Phase Shift Keying (BPSK) V= A sin[2 ft + (t)] f 1 f 2 f p f (t) = Source Basics

  39. Digital Modulation BPSK IQ Diagram Q 1 0 I One Bit Per Symbol Symbol Rate = Bit Rate Source Basics

  40. Digital Modulation ...Quadrature Phase Shift Keying (QPSK) V= A sin[2 ft + (t)] f p 1 = 3 /4 f (t) = f p 2 = /4 f p 3 = - /4 f p 4 = - 3 /4 p f Source Basics

  41. Digital Modulation QPSK IQ Diagram Q 01 00 I 11 10 Source Basics

  42. Digital Modulation p/4 DQPSK IQ Diagram Q I Source Basics

  43. Digital Modulation Modulation Accuracy Magnitude Error (IQ error mag) Q { Error Vector Test Signal f Ideal (Reference) Signal Phase Error (IQ error phase) I Source Basics

  44. Digital Signal Generator Block Diagram IQ Modulator • modulation quality Baseband Generator • modulation quality • adjacent channel performance • supported modulation formats to output section reference section (supplies timing) Source Basics

  45. Digital Modulation PSK Implementation: IQ Method I: Carrier p/2 Q: • Good Interface with Digital Signals and Circuits • Can be Implemented with Simple Circuits • Can be Modified for Bandwidth Efficiency Source Basics

  46. Digital Signal Generator Block Diagram IQ Modulator DAC DAC I from Baseband Generator Ext I to output section from synthesizer section p/2 Q from Baseband Generator Ext Q Source Basics

  47. Digital Signal Generator Block Diagram Baseband Generator From CPU Pattern RAM DAC Constellation Map and Baseband Filters I Data DAC Q Timing Data Clock Symbol Clock Analog Reconstruction Filters Source Basics

  48. 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 Channel Frequency Band 869 - 894 MHz Filtering 0.35 RRC Source Basics

  49. 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 Data 6 6 16 28 122 12 12 122 Mobile to Base Station Source Basics

  50. Applications and Critical Specifications Analog and Digital • Receiver Sensitivity • frequency accuracy • level accuracy • error vector magnitude • Receiver Selectivity • phase noise • spurious • spectral accuracy • Spectral Regrowth • ACP performance Source Basics

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