Manuals / VXI / Lawn and Garden / Portable Generator

VXI 3002 manual Modulation, Frequency generation, Control

Models: 3002

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Chapter 4

TECHNICAL DESCRIPTION

Introduction

The 3002 VXI Signal Generator is a VXI module which covers a wide range of frequencies from 9 kHz to 2.4 GHz. Output levels from -137 dBm to +25 dBm are available. These are C size, 2- slot wide plug-in modules that require a VXI bus mainframe for operation.

The simplified block schematic diagram for the instrument is shown in Fig. 4-1.

Modulation

The carrier frequency can be frequency, phase or amplitude modulated from internal or external sources. The internal source can be the sum of two signals and used in combination with an external source connected to the front panel EXT MOD INPUT connector.

Frequency generation

A voltage controlled oscillator (VCO) covering the frequency range 400 to 533 MHz is phase locked to a 10 MHz temperature controlled crystal oscillator using a fractional-N synthesizer system. Additional frequency coverage is achieved by means of frequency division and multiplication. Low frequencies are generated by a beat frequency oscillator (BFO) system.

Control

Internal control of the instrument is achieved by a microprocessor which receives data and sends instructions via an internal 8-bit data bus to the signal processing circuits.

4-1

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VXI 3002 manual Modulation, Frequency generation, Control

Contents

3002 3002 Document conventions Intended audienceStructure ChapterContents Preface Patent protectionGeneral conditions of use SymbolsSymbol Description Electrical hazards DC supply voltageBeryllia Fire hazardToxic hazards Beryllium copperInstallation Suitability for useConditions générales d’utilisation Symboles signalant un risqueSymbole Nature du risque Sécurité électrique tension d’alimentation continueBronze au béryllium Risque lié au feuLe Béryllia UtilisationPage Allgemeine Hinweise zur Verwendung GefahrensymboleSymbol Gefahrenart Elektrische Schläge GleichspannungsversorgungBeryllium Oxid BrandgefahrWarnung vor giftigen Substanzen Beryllium KupferPericoli da elettricità alimentazione a c.c Simboli di pericoloCondizioni generali d’uso Simbolo Tipo di pericoloBerillio Pericolo dincendioPericolo sostanze tossiche Rame berillioCaratteristiche d’uso Nivel peligroso de electricidad tensión de alimentación DC Símbolos de peligroCondiciones generales de uso Símbolo Naturaleza del peligroBerilio Peligro de incendioAviso de toxicidad Berilio-cobreIdoneidad de uso Chapter ContentsMain features IntroductionMemory IncrementingFrequency sweep TriggersPerformance data FSK Phase ModulationFrequency Modulation Pulse ModulationExternal Modulation Input Sweep ModeInternal LF Generator Frequency StandardElectromagnetic Versions, options and accessoriesSafety CompatibilityReference No Title SafetyCertificate Ref. No. DC230 Qualifying NotesInitial visual inspection Setting logical addressList of figures Ventilation requirementsVisual inspection Installing in VXI mainframeRoutine safety testing and inspection RectificationPutting into storage CleaningFront panel connectors and indicators Switching on Disk installation/loading instructionsDevice talking elements IntroductionDevice listening elements Compound headers ProgrammingProgram messages Message exchange protocol Common commands and queries IeeeProgram data MnemonicDevice dependent commands OPCDefault settings Instrument default settingsCFRQ? Carrier frequencyCfrq RF level RflvRFLVOFFS? RFLV?RFLVLIMIT? OUTPUT? Output controlOutput Mode Modulation modeValid Mode Combinations Table MODE?MOD? Modulation controlMOD Frequency modulation and FSK FM or FM1 or FM2Dcfmnl FMMODF? or FM1MODF? or FM2MODF?Phase modulation PM or PM1 or PM2PMMODF? or PM1MODF? Amplitude modulation AM or AM1 or AM2AM? or AM1? or AM2? PULSE? Pulse modulationPulse Carrier store Memory storesMemory store Full storeRecalling default settings Memory-recallMemory erase Memory sequencingMtrig Memory triggeringMemory protection MTRIG?SWEEPCFRQ? Sweep operationSweep Sweep mode SWEEP?Halt Cont Reset Retn Xfer Sweep controlTrigger Trigger sourceSources TRIGGERSOURCE?Attenuator lock ranges RF level Atten. lock Setting dBm Min. dBm Max. dBm FromAttenuator hold AttenPower-up options Reverse power protectionFrequency standard selection Reading error messagesOperating hours Status byte Status data structure register model Standard event registers ESE ESE?Hardware event registers HSE?Coupling event registers CSE?Instrument event registers SSE SSE?Error Queue Queue flag detailsStatus byte when read by *STB? SRE SRE?Status byte when read by serial poll Service Request Generation Service Request Enable Register#Summary of status reporting commands and queries Foreground errors Error handlingBackground errors Error queueError Messages Background errors 500 599 in priority orderForeground errors 0 Ieee 488.2 errors 400 Control ModulationFrequency generation Block schematic diagram Acceptance Testing Test precautionsRecommended test equipment Executable soft front panel softwareRF output SpecificationDescription Minimum specification Example Test equipmentALC linearity Test procedureRF level frequency response Attenuator accuracy MeasuringCarrier frequency accuracy CounterSpectrum analyzer Spectral purityHarmonics Non-harmonics Residual FMSSB phase noise SSB phase noise test set-upInternal FM FM deviation and distortionFM scale shape Hz to 100 kHz Carrier errorExternal FM frequency response ALC off, DC coupled External FM frequency response ALC on Hz DCPhase modulation Phase modulation flatnessAM depth and distortion Figure recorded in 5 20 log10 Figure recordedExternal AM frequency response ALC off, DC coupled Test procedure Hz to 30 kHzAM scale shape DVM Pulse modulation RF level frequency response 10 Pulse modulation test set-upPulse modulation on/off ratio Function generatorModulation oscillator Pulse modulation rise and fall timeModulation oscillator frequencies Modulation oscillator distortion and LF output flatnessExternal frequency standard input 15 External standard test set-upFor 3002 Signal Generator, serial number RF output at −4 dBmRF output at +7 dBm RF output at +25 dBm +19 dBmALC linearity at 2.5 MHz RF level dBm RF level min DBm Result dBm RF level maxALC linearity at 950 MHz ALC linearity at 1200 MHz ALC linearity at 1900 MHz ALC linearity at 2400 MHz Attenuator test at 2.6 MHz RF level dBm RF level min Result dBm RF level max DBm10 Attenuator test at 480.1 MHz 11 Attenuator test at 1199 MHz 12 Attenuator test at 1875.1 MHz 13 Attenuator test at 2399 MHz 14 Carrier frequency tests Frequency MHz Frequency min Result MHz Frequency max15 Carrier harmonic tests at −4 dBm 16 Carrier harmonic tests at +7 dBm 17 Carrier harmonic tests at +13 dBm 18 Carrier harmonic tests at +19 dBm 20 Residual FM test 21 SSB phase noise test19 Carrier non-harmonic tests Carrier frequency Residual FM Measured value Hz RMS23 FM scale shape tests at 15 MHz carrier FM deviation kHz Result kHz Min. kHz Max. kHz24 Carrier error test at 1.2 GHz, FM deviation 100 kHz Carrier error Result kHz10.5 31 Internal AM depth and distortion tests at +7 dBm 29 Internal ΦM flatness test30 Internal AM depth and distortion tests at −4 dBm 32 Internal AM depth and distortion tests at +13 dBm 33 Internal AM depth and distortion tests at +19 dBm34 AM scale shape test AM depth % AM depth min Result % Max. %38 Pulse modulation RF output at −7 dBm 39 Pulse modulation RF output at +4 dBm 40 Pulse modulation RF output at +14 dBm Pulse modulation on/off ratio test45 External frequency standard tests Modulation oscillator frequency tests44 Modulation oscillator distortion and LF output tests General description Acceptance testingAnnex a OperationTest procedure Spectrum analyzerAnnex-A-3 Table A-1 Pulse mod. RF output at −7 dBm Table A-2 Pulse mod. RF output at +0 dBm Table A-3 Pulse mod. RF output at +16 dBm Result ns Table A-4 Pulse modulation on/off ratio testTable A-5 Pulse modulation rise and fall time test Software Licence and Warranty Indemnity UK Stevenage Email info-test@aeroflex.comChina Shanghai China Beijing