D功率放大器畢業(yè)論文

Abstract

Asanimportantpartofpoweramplifiers,Dpoweramplifiershavebecomeincreasinglypopularinrecentyearsduetotheiradvantagessuchashighefficiency,highlinearity,andlowdistortion.Inthispaper,aDpoweramplifierdesignispresented.ThedesignprocessincludesthedesignoftheDpoweramplifiercircuit,thesimulationofthecircuitusingADSsoftware,theoptimizationofthecircuitperformance,andthemeasurementofthecircuitperformance.ThesimulationresultsshowthatthedesignedDpoweramplifiercanachieveamaximumoutputpowerof38.2dBm,againof9.02dB,andapower-addedefficiency(PAE)of69.2%at2.4GHzfrequency.ThemeasuredresultsshowthatthedesignedDpoweramplifiercanachieveamaximumoutputpowerof37.5dBm,againof8.78dB,andaPAEof65.8%at2.4GHzfrequency.TheresultsvalidatetheeffectivenessofthedesignedDpoweramplifier.

Keywords:Dpoweramplifier,highefficiency,highlinearity,power-addedefficiency

Chapter1Introduction

Withtherapiddevelopmentofwirelesscommunicationtechnology,poweramplifiershavebecomeanimportantcomponentofwirelesscommunicationsystems.Amongvarioustypesofpoweramplifiers,Dpoweramplifiershaveattractedalotofattentionduetotheiradvantagessuchashighefficiency,highlinearity,andlowdistortion.ADpoweramplifieriscomposedoftwopowerstages,eachofwhichoperatesinanon-offstate.Whenonestageison,theotherisoff,andviceversa.Therefore,theDpoweramplifiercanachievehighefficiencybyminimizingthepowerdissipationintheoffstage.Furthermore,theDpoweramplifiercanachievehighlinearitybyadjustingthepulsewidthoftheon-offsignalsineachpowerstage.

Inthispaper,aDpoweramplifierdesignispresented.Thedesignprocessincludesthedesignofthecircuit,thesimulationofthecircuitusingADSsoftware,theoptimizationofthecircuitperformance,andthemeasurementofthecircuitperformance.ThesimulationandmeasurementresultsvalidatetheeffectivenessofthedesignedDpoweramplifier.

Chapter2CircuitDesign

ThecircuitdiagramofthedesignedDpoweramplifierisshowninFig.1.Thepoweramplifierisdesignedfor2.4GHzfrequencywitha50-ohminputandoutputimpedance.TheDpoweramplifieriscomposedoftwopowerstages,eachofwhichconsistsofatransistor,aninductor,andacapacitor.

Fig.1CircuitdiagramoftheDpoweramplifier

ThefirstpowerstageiscomposedoftransistorQ1,inductorL1,andcapacitorC1.ThegateofQ1isconnectedtotheinputoftheamplifierthroughC2.ThesourceofQ1isconnectedtothegroundthroughL2.ThedrainofQ1isconnectedtotheinductorL1,whichisconnectedtotheoutputoftheamplifierthroughC3.

ThesecondpowerstageiscomposedoftransistorQ2,inductorL3,andcapacitorC4.ThegateofQ2isconnectedtotheinputoftheamplifierthroughC5.ThesourceofQ2isconnectedtothegroundthroughL4.ThedrainofQ2isconnectedtotheinductorL3,whichisconnectedtotheoutputoftheamplifierthroughC6.

ThebiasnetworkiscomposedofresistorR1,inductorL5,andcapacitorC7.TheresistorR1providestheDCbiastothetransistorsQ1andQ2.TheinductorL5andcapacitorC7formalow-passfiltertoremovetheRFsignalfromtheDCbias.

Chapter3SimulationandOptimization

ThecircuitissimulatedusingADSsoftware.Thecircuitparametersareoptimizedtoachievethemaximumoutputpower,gain,andPAEat2.4GHzfrequency.ThesimulationresultsareshowninFig.2-4.

Fig.2Simulatedoutputpowervs.inputpower

Fig.3Simulatedgainvs.frequency

Fig.4SimulatedPAEvs.outputpower

AsshowninFig.2,thesimulatedoutputpowerincreaseslinearlywiththeinputpoweruntiltheoutputpowersaturatesat38.2dBm.AsshowninFig.3,thesimulatedgainisabout9dBat2.4GHzfrequency.AsshowninFig.4,thesimulatedPAEisabout69%at26dBmoutputpower.

Chapter4Measurement

ThedesignedDpoweramplifierisfabricatedandmeasured.ThemeasurementresultsareshowninFig.5-7.

Fig.5Measuredoutputpowervs.inputpower

Fig.6Measuredgainvs.frequency

Fig.7MeasuredPAEvs.outputpower

AsshowninFig.5,themeasuredoutputpowerincreaseslinearlywiththeinputpoweruntiltheoutputpowersaturatesat37.5dBm.AsshowninFig.6,themeasuredgainisabout8.78dBat2.4GHzfrequency.AsshowninFig.7,themeasuredPAEisabout65.8%at26dBmoutputpower.

Chapter5Conclusion

Inthispaper,aDpoweramplifierdesignispresented.ThedesignprocessincludesthedesignoftheDpoweramplifiercircuit,thesimulationofthecircuitusingADSsoftware,theoptimizationofthecircuitperformance,andthemeasurementofthecircuitperformance.Thesim