reconfigurable fully digital transmitter with carrier-frequency pulse-width modulation

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1、Reconfigurablefullydigitaltransmitterwithamplitude-modulatedsine-wavebyaBPFwithcarrierharmonicscarrier-frequencypulse-widthmodulationsuppressed.Fortheexistingdesign[3]whereitisthepulsedensitiesratherthanB.Zhou,K.Zhang,W.ZhouandD.Liuthepulse-widthsofthecarrierclockthatrepresentthebasebandenvel

2、-opes,theBPFhandlingstandardsquarewaveswithafixeddutycycleof0.5,doesnotencounteranygaindistortion.However,fortheproposedAreconfigurablefullydigitaltransmitterwithcarrier-frequency(CF)pulse-widthmodulation(PWM)isimplementedin180nmCMOSarchitecturewithpulse-widthorduty-cyclemodulatedsquarewaves,th

3、eforlowCFapplications.Throughdelaylines,basebandphasesareoutputsineamplitudeyandinputduty-cycledoftheBPFconformtomappedtopositiondelaysof1/4periodofacarrierclock.With(1),accordingtotheFourierseriesexpansionoftheperiodicsquaredelaylinesbasedCFPWM,pre-correctedbasebandenvelopesarewave[4].Thatis

4、,theBPFintroducesenvelopedistortionsanddegradesconvertedtopulse-widthsoftheposition-modulatedcarrierclock.theoriginalrising-edgephaseshiddeninthemodulatedcarrier.ToBoththepulse-widthsandthepositionsofthemodulatedcarrierensuremodulationlinearity,aquantisationpre-correctionmodulewithclockareamp

5、lifiedandreshapedtothesine-wavecarrierwiththeinversefunctionof(1)isaddedtotheenvelopepath,andpositionbasebandcomponentsbythesequentswitched-modepoweramplifierdelaysof1/4period(90°-shiftedpoints)ratherthanrising-edgesofandabandpassfilter.Thecircuit-levelsimulationresultsverifythatthecarrierclocka

6、remodulatedtorepresentthephasecomponentstheproposedimplementationachievesreconfigurableCFand20dBspectrumoptimisation,whencomparedwiththeexistinginter-2mediate-frequencyPWMbaseddesigns.y=sin(p×d)(1)pThefunctiondiagramoftheproposedarchitectureisshowninFig.2.Introduction:Someaudiocommunications,s

7、uchasthejointtacticalradiosystem(JTRS),requirehandheldtransmitterdevicesfeaturingForacertainCFfC,theN-stagedelaylinewithaunitdelayof1/(N×fC)convertsthequantisedphaseXtotherising-edgelagofthecarrierclock.lowcarrierfrequency(CF),highspectrumpur