LDMOS-TRANSISTOR-DESIGN.TextMark内匹配讲座

InternalMatchingofLDMOSPowerTransistorYinanWang18/10/2011ForASBCOMPANYCONFIDENTIALContentsLDMOSTechnologyInternalMatchingTheoryTransistorDesignFlow2ForASBCOMPANYCONFIDENTIALLDMOSTechnology3ForASBCOMPANYCONFIDENTIALNXPLDMOSTechnologyDiePerformance4ForASBCOMPANYCONFIDENTIALWhyinternalmatchingPCBsandcomponentshavesmallamountsofloss–apracticallowerlimit(0.75Ohm)impedancestestcircuitscanpresent.Higheroutputpowerlowertheimpedance(greaterthetransformationratio)–thesmallbandwidthofthematchingnetwork.5ForASBCOMPANYCONFIDENTIALInternalmatchingofPowertransistor6ForASBCOMPANYCONFIDENTIALPrematch7PrematchcapLg2ActivedieLg1LeadPackageparaciticsPrematchcapacitorActivedieLg1Lg2PackageparaciticsPrematchcapacitorActivedieLg1Lg2ForASBCOMPANYCONFIDENTIALPrematchLowPassMatchingTopologyHigherQ=worsebandwidthPotentiallylesslossduetohigherQofsmallshuntcapacitor8ForASBCOMPANYCONFIDENTIALPrematchResonatefrequencyCout&Lg1ResonatefrequencyInputcapacitance(Cin)andtheinductor(Lg1)fromdietopermatchcapacitorLowpass,200MHzabovethebandofoperationGainenhancement–prematcheffectImprovedvideobandwidthduetosmallervalueofshuntcapacitor.9ForASBCOMPANYCONFIDENTIALPrematchResonancetoocloseorinsidethebandresultsin:Largevariationofinputimpedance-LowerproductionyieldPotentialriskofgainpeakingandpossiblyinstabilitiesHighertransistorinsertionphasevariation(Doherty)√Higherimpedances101.01.52.02.53.03.54.04.50.55.0-50510152025-1030freq,GHzreal(Z1)ReadoutLowReadoutHighimag(Z1)Lowfreq=real(Z1)=2.5872.500GHzHighfreq=real(Z1)=6.1932.700GHz1.01.52.02.53.03.54.04.50.55.0-50050-100100freq,GHzphase(Z1)ForASBCOMPANYCONFIDENTIALInShIninshin:InternalShuntInductor11ActivedieoutputcapacitanceLiCi(DCblock)LdPackageparaciticsActivedieLiCi(DCblock)LdPackageparaciticsActivedieLiLdInshincapacitorLeadForASBCOMPANYCONFIDENTIALInShInHighPassMatchingTopologyLowerQ=betterbandwidthPotentiallyhigherlossduetopoorQoflargeblockingcapacitor12ForASBCOMPANYCONFIDENTIALInShInResonatefrequencyoutputcapacitance(Cout)andtheinshin(Li)inductorHighpass,100MHzbelowthebandofoperationDegradedvideobandwidthduetolargeDCblockingcapacitor.MutualcouplingbetweenLiandLdhoweverhasanegativeeffectonmatching.13ForASBCOMPANYCONFIDENTIALInShInResonancetoocloseorinsidethebandresultsin:Largevariationofoutput(load)impedance-LowerproductionyieldPotentialruggednessriskHigheroff-stateimpedancevariations(Doherty)√HigherimpedanceswithlowerQ,whichresultsinmorepeakpowerandbetterefficiency(betteroverallperformance)141.01.52.02.53.03.54.04.50.55.0-10010203040-2050freq,GHzreal(Za)ReadoutLowReadoutHighimag(Za)Lowfreq=real(Za)=11.2462.500GHzHighfreq=real(Za)=10.0792.700GHzForASBCOMPANYCONFIDENTIALBackBending15MForASBCOMPANYCONFIDENTIALVWBBiasnetworksneedtopresentthelowandconstantimpedanceovertherequiredfrequencybandTheMOSCAPalongwiththeinductorsandthebiascircuitryformsaresonantcircuitThesmallertheinshin-capacitoris,thebetterthevideo-decouplingwillbe,sincetheresonancefrequencywillbehigher16decouplingnetworkshuntcapacitorbiasquarter-waveline501001502002503003504004500500-50-40-30-20-10-600freq,MHzdB(S(2,1))dB-TRANSMISSION501001502002503003504004500500-1000100-200200freq,MHzphase(S(2,1))phase-TRANSMISSIONForASBCOMPANYCONFIDENTIALCross-bondswiresCross-bondsareusedforstabilityreasons.17ForASBCOMPANYCONFIDENTIALInternalMatchingforDifferentDeviceInternalmatchingcanbesplitinroughly3groupsNointernalmatching.–Doneforlowpowerdevices(Wg20mm)upto2.5GHz–Doneforpowerdevicesonlowfrequencies(400MHz)Onlyinputmatching–Doneforlowpowerdevices(Wg20mm)from2.5GHzupwards–Doneforpowerdevicesuseduptoappr.1GHzBothinputandoutputmatching–Doneforallhighpowerdevicesfrom1GHzupwards.–(Outputmatchingfordevicesusedfrom1to1.5GHzmustbeconsideredseparately)18ForASBCOMPANYCONFIDENTIALThecomposedcomponentsofRFtransistorTuningsmallsignalperformance:impedance,resonances,lowQ1912345ForASBCOMPANYCONFIDENTIALDesignFlowModelPackageRingframeSetupDiemodelinput/outputDesigninternalinput/outputmatchingWithLEcomponents,diemodelandRingframeTranslationintoBWmodelFinetuneinput/outputmatchingwithBWmodelLoadpullsimulationoffinaltransistor20ForASBCOMPANYCONFIDENTIALLoadpull21ForASBCOMPANYCONFIDENTIALLoadpull22ForASBCOMPANYCONFIDENTIALLDMOST,Wg=18mm0102030405060708001020304050Vsupply(V)peak-Eff(%)Voltageandfrequencyscaling3.5GHz2.0GHz1.0GHzParallellossesSerieslosses23ForASBGaNHEMTForASBCOMPANYCONFIDENTIAL25ForASBCOMPANYCONFIDENTIALGaN26ForASBCOMPANYCONFIDENTIALGaN27ForASBCOMPANYCONFIDENTIALGaNNXPDemoonIMS2011–50WwidebandGaNamplifiercovering500to3000MHz;–2.1GHzand2.7GHzDohertypoweramplifiersforbasestations;–100-Wamplifiercovering2.5-3.5GHz.SMPA28ForASBCOMPANYCONFIDENTIALLDMOST,Wg=18mm0102030405060708001020304050Vsupply(V)peak-Eff(%)Voltageandfrequencyscaling3.5GHz2.0GHz1.0GHzParallellossesSerieslosses29ForASB