ECEN650HIGHFREQUENCYICDESIGN

PROJECTREPORT

CLASSEAMPLIFIER

ARUNPALANIAPPAN(UIN:XXXXX4604)

Specification

DesignaclassEpoweramplifierusingtheGaAspHEMTtechnology(usingonlydepletionmodedevices)withthefollowingspecifications:

fop=1GHz Prf=1W PoweraddedEfficiency80% Powergain20dB RS=RL=50 Singlesupply

Noidealsourcesotherthanthesinglevoltagesupplyareallowed.Fortheinputsignal,a0.5Vsinewaveat1GHzshouldbeused.Provideallcalculations,schematics,layoutandpostlayoutsimulationresults. Class-E amplifier

ClassEpoweramplifierisatunedpoweramplifiercomposedofasinglepoleswitchandaloadnetwork.TheloadnetworkcontainsaseriesresonantLCcircuit,aDCdrainsupply,andadrainshuntcapacitor.The load issimplya resistance.Preceding the loadnetwork is theswitch. Inordertoachieveahighefficiency,thepeakofthecurrentandvoltagewaveformsfortheswitchmustbedisplacedinthetime.Whentheswitchisturnedon,thecurrentflowsthroughitwithnovoltagedropacross.Ontheopposite,therewillbeavoltageinducedwhentheswitchisoff,blockinganycurrentflow.Thus,thetwowaveformsbehaveliketwopulsetrains,bothwithfallandrisesectionsoccupying50%oftheRFperiod,ideally.Itisrequiredthattherisesectionof

onewaveformoccurswhentheotheroneisinitsfalltoavoidpeakingsimultaneouslywhichisshowninthefigurebelow.

DesignEquationsandProcedureDesignEquationsfrom[1]wereusedinthedesignprocessofthisproject.Firstweneedtosetthesupplyvoltageofthisamplifier.

3.56

.

Here,BVCEVisthebreakdownvoltageoftheMESFETdevicetobeusedandSFisthesafetyfactor.Wetakethesafetyfactoras80%andcalculateVccfromthebreakdownvoltageof15V

153.56

. 0.8 3.37

Wesetthe .

Next,wecalculatetheloadresistancetobeusedusingthepowerspecification.

0.5768011.001245 0.451759

0.402444

AssumingQL=5andgivenPout=1W,weget

. TheshuntcapacitanceC1isgivenbythefollowingequation

1

34.2219 0.99866

0.91424

1.03175

0.62

Given,theoperatingfrequencyas1GHzandusingRLfromthepreviousequationweget

5.9286 0.6

2

TheusualchoiceofXL1being30ormoretimestheunadjustedvalueofXC1UsingtheaboveunadjustedC1valuetocalculateL1,weget

30.

. 30

. 30 26.8452 . 805.353 128.18

WesetL1=150nHUsingthisL1valueandcalculatingC1weget

5.9286 101.32Therefore, . .ThiscapacitancealsoincludesthedrainparasiticsoftheclassEswitch.So,inthecircuitweuseacapacitanceof3.6pFforC1,therestisaccountedbythedrainparasiticsofthepHEMTswitch.TheequationforcalculatingC2isgivenasfollows

1

2

1 0.104823

1.00121 1.01468

1.7879

0.22

Substitutingvaluesneeded,weget . Finally,L2isobtainedasfollows

.2

Substituting,weget . Weneedtodelivertheoutputpowerof1Wtoaloadof50.Butbasedonthepower,wecalculatedtheresistanceas5.62.Soweneedanoutputmatchingnetworktodeliverthepowerto50load.WeusethefollowingLsectiontomatch5.62to50load.

Theequationsnecessaryforthetransformationare

1

Usingtheabovetwoequationsweget,

. . AMatlabCodewaswrittenusingalltheseequationstofacilitatecalculationoftheseparameters.TheMatlabcodeisgiveninAppendixA.Asfortheswitch,MESFETtransistorswereused.Thewidthofthetransistorswasobtainedempiricallytogetthemaximumperformance.Weobtainedthewidthas

TheC1capacitanceusedwasreducedto3.6pFtoaccountforthedrainparasiticsoftheswitchtransistor.C2wasalsoslightlyreducedto7.05pFfrom7.5pFtogethigheroutputpower.

TheClassEamplifier inputwaveform is very critical to itsperformance. Soweusea class FdrivertogiveaproperinputtotheclassEstage.Theinputisgivenassinewave0.5Vat1GHz.WeneedtoshapethisinputwaveformsuchthattheclassEgivesgoodperformance.WeneedtokeepthisinmindinthedesignofclassFstage.ClassFdriverstage

TheClass F driverwas designed to provide the suitable switchingwaveform for theClass Epower amplifier. It consists of a depletion mode MESFET, two paralleltuned LC circuitsresonatingatthefirstandthirdharmonicsoftheinputfrequencyandabypasscapacitorattheinputandoutput.ThefinalinductorattheoutputisusedtochangethedcvalueoftheclassFoutputtosuitthedcvaluefortheclassEinput.TheinductanceismadetoresonatewithclassEinputcapacitancesothatthereisnodropinthesignal.ThevoltagesourceVsis0.5Vsinewaveat1GHzwithRsinputimpedanceas50.WehavetakenthebypasscapacitancesCbattheinputandoutputtobe10pFLd1 and Cd1 aremade to resonate at the input frequency and Ld3 and Cd3 aremade toresonateatthethirdharmonicofinputfrequency.TakingCd1as6pF,wegetLd1as4.22nH.WegetCd3as2pFandLd3as1.4067nHWemeasuredtheinputcapacitancetobearound6pFandwemakeLgas4nHThewidthofthetransistorisdecidedbasedongoodoutputwaveformwhichdrivestheclassEbetterandgivesbetterperformancetotheclassEamplifier.Thewidthisobtainedas110m.

ClassFdriverstagewithClassEpoweramplifier

Next,weputtheabovedesignedclassFdriverandClassEamplifiertogether.Wesimulatethiscircuitandseeitsresponse.SchematicofclassEpoweramplifierdrivenbyclassFdriver

TestBenchSchematic

ClassFdriverstagewaveforms

ClassEpoweramplifierwaveformsshowingvoltageacrossswitchandcurrentthroughtheswitch

ClassEpoweramplifieroutputwaveforms

PowerandEfficiencyofClassEamplifier

OutputPower=1.028W,DCPower=1.428W,InputPower=216.5WPowerAddedEfficiency=(PoutPin)/Pdc=71.97%72%Powergain=Pout/Pin=4748.27=36.765dBTableshowingPreLayoutsimulationresults

Parameter Specificationgiven PreLayoutSimulationf0 1GHz 1GHz

Prf=Pout 1W 1.028WPdc 1.428WPin 216.5W

PowerAddedEfficiency >80% 72%Powergain >20dB 36.765dB

RS=RL 50 50Afterthisthelayoutwasdone.Theinductorsusedinthelayoutwereideal.

Layout

DesignRuleCheck(DRC)Report

ExtractedReport

LVSMatch@(#)$CDS:LVS.exeversion5.1.006/20/200702:37(cicsun11)$Command line: /baby/cadence/ic5141usr5/tools.sun4v/dfII/bin/32bit/LVS.exe dir/home5/arunpece/cadence_tqped/LVS l s t /home5/arunpece/cadence_tqped/LVS/layout/home5/arunpece/cadence_tqped/LVS/schematicLikematchingisenabled.Netswappingisenabled.Usingterminalnamesascorrespondencepoints.Netlistsummaryfor/home5/arunpece/cadence_tqped/LVS/layout/netlistcount 11 nets 4 terminals 11 tqped_phss 7 tqped_cap 6 tqped_mrindNetlistsummaryfor/home5/arunpece/cadence_tqped/LVS/schematic/netlistcount 11 nets 4 terminals 6 tqped_phss 7 tqped_cap 6 tqped_mrind

TerminalcorrespondencepointsN7N2InN16N9OutN2N1VddN14N7VssDevicesintherulesbutnotinthenetlist:tqped_elsstqped_plsstqped_ehsstqped_eh2stqped_eh3stqped_ph2stqped_ph3stqped_ph4stqped_ph5stqped_ph6stqped_dmltqped_demltqped_resThenetlistsmatchlogicallybuthavemismatchedparameters. layoutschematic instances unmatched 0 0 rewired 0 0 sizeerrors 11 6 pruned 0 0 active 24 19 total 24 19 nets unmatched 0 0 merged 0 0 pruned 0 0 active 11 11 total 11 11 terminals unmatched 0 0 matchedbut differenttype 0 0 total 4 4Probefilesfrom/home5/arunpece/cadence_tqped/LVS/schematicdevbad.out:netbad.out:mergenet.out:

termbad.out:prunenet.out:prunedev.out:audit.out:I/J2?ParameterWmismatch:layout1.1e10vs.schematic0.00011I/J3?Combineddevice:ParameterWmismatch:layout2e09vs.schematic0.002I/J1?Combineddevice:ParameterWmismatch:layout2e09vs.schematic0.002I/J0?Combineddevice:ParameterWmismatch:layout2e09vs.schematic0.002I/J16?Combineddevice:ParameterWmismatch:layout2e09vs.schematic0.002I/J15?Combineddevice:ParameterWmismatch:layout2e09vs.schematic0.002Probefilesfrom/home5/arunpece/cadence_tqped/LVS/layoutdevbad.out:netbad.out:mergenet.out:termbad.out:prunenet.out:prunedev.out:audit.out:Theno.oflinesexceededthanspecifiedbythevariablelvsLimitLinesInOutFile.Toseethecompleteinformationpleaseseethefile:/home5/arunpece/cadence_tqped/LVS/layout/audit.out

PostLayoutSimulationsInputandOutputwaveforms

Powerwaveforms

OutputPower=1.027W,DCPower=1.426W,InputPower=216.6W

PowerAddedEfficiency=(PoutPin)/Pdc=71.96%72%Powergain=Pout/Pin=4741.45=36.759dBTableshowingPreLayoutandPostLayoutsimulationresults

Parameter Specificationgiven PreLayoutSimulations

PostLayoutSimulations

f0 1GHz 1GHz 1GHzPrf=Pout 1W 1.028W 1.027W

Pdc 1.428W 1.426WPin 216.5W 216.6W

PowerAddedEfficiency

>80% 71.97%72% 71.96%72%

Powergain >20dB 36.765dB 36.759dBRS=RL 50 50 50

WeseethatPreLayoutandPostLayoutsimulationresultsareprettymuchthesamebecausethe inductorsused in the layoutwere ideal i.e., the tooldidntextract the inductance valueproperlyandwehadtoedittheextractedviewtospecifythe inductancevalue.Theparasiticdue to the capacitancesand transistorsarenotmuch inorder to cause changes in thepostlayoutsimulations.SummaryoftheProjectThuswedesigned a class Epower amplifierusingpHEMTdevices tooperate at1GHz anddeliver 1W powerwith a power gain of 36.76 dB. The power added efficiency required isgreater than80%.But theobtainedpoweraddedefficiency is72%.Theefficiencyof classEdependsonitsinputwaveform.TheclassFstagewhichproducestherequiredwaveformattheinput of class E amplifier does not give an exact squarewave for switching. This causes adecrease inefficiency.TheclosertheclassFoutput istosquarewaveform,thebetterwillbethe efficiency of the class E amplifier. Addingmore number of harmonicswill give a shapecloser to squarewaveformbut itwill increase the area.Also,when the inputof the class Eamplifiergoesbeyond0.5V thediodegets forwardbiasedand there is smallpowerwastageanddecrease inefficiency.Weshouldrestrictthewaveformat the inputofclassEnot togomuchbeyond0.5V.Theabovemethodscangetuscloselytoapoweraddedefficiencyof80%.

AppendixAMatlabCodeforClassEpassivecomponentscalculationclc;clear;fo=1e9%operatingfrequencyinGHzPout=1%desiredoutputpowerinWattsQL=5%loadedqualityfactorofCoLoseriesresonantcircuitL1=150e9%L1isthevalueforRFchokeusedinnanoHenryRH=50%GivenoutputloadinohmsVDD=3.3%draindcsupplyvoltageinVoltsRL=(VDD^2/Pout)*0.576801*(1.0012450.451759/QL0.402444/(QL^2))%calculatetheloadresistancebasedonpowerC1=(1/(34.2219*fo*RL))*(0.99866+0.91424/QL1.03175/(QL^2))+0.6/((2*pi*fo)^2*L1)%calculatethedrainshuntcapacitanceC2=(1/(2*pi*fo*RL))*(1/(QL0.104823))*(1.00121+1.01468/(QL1.7879))0.2/((2*pi*fo)^2*L1)%calculatethecapacitanceinCoLoseriesresonatecircuitL2=QL*RL/(2*pi*fo)%calculatetheinductanceinCoLoseriesresonatecircuitQ=sqrt((RH/RL)1)%QfortheoutputmatchingnetworkLsoutput=Q*RL/(2*pi*fo)%OutputmatchingnetworkinductanceCpoutput=Q/(RH*2*pi*fo)%OutputmatchingnetworkcapacitanceTheoutputofthiscodeisasfollowsfo=1.0000e+009Pout=1QL=5L1=1.5000e007RH=50VDD=3.3000RL=5.6205C1=6.0294e012C2=7.5852e012

L2=4.4727e009Q=2.8100Lsoutput=2.5136e009Cpoutput=8.9444e012

References[1]ClassERFPowerAmplifiersbyNathanO.Sokal,2001[2]Design andDevelopmentof theClass ERFPowerAmplifierPrototypebyUsing aPowerMOSFETbyTiaotiaoXie,UniversityofKansas,2007[3]RFPowerAmplifiersforWirelessCommunicationsbySteveCripps,SecondEdition[4] LowVoltage,High EfficiencyGaAsClass EPowerAmplifiers forWireless Transmitters byTirdadSowlati,AndreT.Salama,JohnSitch,GordRabjohnandDavidSmith,1995[5]A Fully IntegratedClassE CMOSAmplifierwith a ClassFDriver Stage byChienChihHo,ChinWeiKuo,ChaoChihHsiao,andYiJenChan