ads功率放大器设计官方指导.pdf

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1、AgilentEEsofEDAThisdocumentisownedbyAgilentTechnologies,butisnolongerkeptcurrentandmaycontainobsoleteorinaccuratereferences.Weregretanyinconveniencethismaycause.ForthelatestinformationonAgilent’slineofEEsofelectronicdesignautomation(EDA)productsandservices,pleasegoto:www

2、.agilent.com/find/eesofPowerAmplifierDesignusingADSPAWorkshopWilfredoRivas-TorresTechnicalSupportApplicationEngineerOctober12,2004Page1Outline•Introduction•DCandLoadlineanalysis•BiasandStability•LoadPull•MatchingusingSmithChartUtility•SourcePull•PACharacterization–Didweme

3、etthespecification?•Optimize/FineTunethedesign•TestDesignwithrealworldmodulatedsignals•LayoutPage2ADSPowerAmpDesignWhydoweneedaPowerAmplifier?PowerAmplifiers(PA)areinthetransmittingchainofawirelesssystem.Theyarethefinalamplificationstagebeforethesignalistransmitted,andth

4、ereforemustproduceenoughoutputpowertoovercomechannellossesbetweenthetransmitterandthereceiver.BasicTransmitterBasebandMODDriverPAOSCPage3ADSPowerAmpDesignPArequirements•ThePAistypicallytheprimaryconsumerofpowerinatransmitter.AmajordesignrequirementishowefficientlythePAca

5、nconvertDCpowertoRFoutputpower.•ThedesignengineerhastooftenconcernhimselfwiththeEfficiencyofthePowerAmplifier.Noticethatefficiencytranslatesintoeitherloweroperationcost(e.g.cellularbasestation)orlongerbatterylife(e.g.wirelesshandheld).•PAlinearityisanotherimportantrequir

6、ement,theinput/outputrelationshipmustbelineartopreservethesignalintegrity.•ThedesignofPAsofteninvolvesthetradeoffofefficiencyandlinearity.Page4ADSPowerAmpDesignPADesignRequirement•RFOutputPower:50WPEP•InputDriveLevel:1W•OutputLoad(RL):50Ω•Efficiency(η)>50%•BiasVoltage:28

7、V•Device:MRF9045MPage5ADSPowerAmpDesignDCCurvesFETCurveTracerI_ProbeV_DCIDSSRC1Vdc=VDSFSL_MRF_MET_MODELVJMRF1VarVARMODEL=MRF9045MEqnV_DCVAR1VDS=0VSRC2Vdc=VGSVGS=0VPARAMETERSWEEPDCParamSweepDCSweep1DC1SweepPlan="SwpPlan1"SweepVar="VDS"Start=2.5Start=0Stop=5.0Stop=28*2Step

8、=0.1Step=0.1SetdrainandgatevoltageFSL_TECH_INCLUDEsweeplimitsasneeded.FSL_TECH_INCLUDEDispDisplayTempla