【英文资料】40 GHz MMIC Power Amplifier in InP DHBT Technology.ppt

40 GHz MMIC Power Amplifier in InP DHBT Technology,Outline,LEC 2002,UCSB,IntroductionTransferred-Substrate Power DHBT TechnologyCircuit DesignResultsConclusion,Introduction,LEC 2002,Applications for power amplifiers in Ka bandsatellite communication systems wireless LANs local multipoint distribution system personal communications network links and digital radio MMIC Amplifiers in this frequency bandKwon et.al.,IEEE MTT,Vol.48,No.6,June.2000 3 stage HEMT,class AB,Pout=1 W,Gain=15 dB,PAE=28.5%,size=9.5 mm2 This Work:Single stage cascode InP DHBT,class A,Pout=50 mW,Gain=7 dB,PAE=12.5%size=0.42 mm2,Transferred-Substrate HBT MMIC fabrication,MBE DHBT layer structure,Band profile at Vbe=0.7 V,Vce=1.5 V,InP 8E17 Si 300,400 InGaAs base3000 InP collector,Small-area T.S.DHBTs have high cutoff frequencies.,UCSB,Sangmin Lee,BVCEO=8 V at JE=0.4 mA/m2,fmax=462 GHz,ft=139 GHz,Vce(sat)1 V at 1.8 mA/m2,Design difficulties with large-area power DHBTs,UCSB,Yun Wei,ARO MURI,Thermal instability further increasescurrent non-uniformity,Ic,Temperature,Steady state current and temperature distribution when thermally stable,base feed sheet resistance:s=0.3/significant for 8 um emitter finger length,Large Area HBTs:big Ccb,small Rbb,even small excess Rbb substantially reduces fmax,0.08 m,Emitter contact,Metal1,Base contact,Current hogging in multi-finger DHBT:,Distributed base feed resistance:,K1 for thermal stability must add emitter ballast resistance,Initial current and temperature distribution,thermal feedback further increases current non-uniformity,8 finger common emitter DHBTEmitter size:16 um x 1 um Ballast resistor(design):9 Ohm/finger,Jc=5e4 A/cm2 Vce=1.5 V,First Attempt at Multi-finger DHBTs:Poor Performance Due to Thermal Instability,thermally driven current instability b collapse,UCSB,low fmax due to premature Kirk effect(current hogging)excess base feed resistance,ARO MURI,Yun Wei,Large Current High Breakdown Voltage Broadband InP DHBT,UCSB,8-finger DHBT8 x(1 mm x 16 mm emitter)8 x(2 mm x 20 mm collector)Key Improvements8 Ohm ballast per emitter finger2nd-level base feed metalDevice Performancefmax330 GHz,Vbrceo7 V,Jmax1x105 A/cm2100 mA,3.6 Volt device,2nd-level base feed metal,Ballast resistor,emitter,collector,Flip chip,Yun Wei,ARO MURI,UCSB,HBT power amplifier-why cascode?,ARO MURI,Yun Wei,IB1,*R.Ramachandran and A.F.Podell Segmented cascode HBT for microwave-frequency power amplifiers,Advantages:common-base stage has large Vce large output power common-emitter-stage has low Vce small Rballast required maintains large available power gain Disadvantageinductance of base bypass capacitoreven small L greatly degrades gain,Vce1,Vce2,+,-,+,-,IE1,Rballast,IE2,radial stub capacitor,UCSB,InP TS DHBT Power Amplifier Design,ARO MURI,Yun Wei,Optimum admittance match,Input match,Low frequency stabilization,8 finger cascode,Inter-stage DC bias,/4,/4,40 GHz 128 mm2 power amplifier,UCSB,cascode PA,0.6mm x 0.7 mm,AE=128 mm2,ARO MURI,f0=40 GHz BW3dB=16 GHz GT=7 dB P1dB=14 dBm Psat=17 dBm 4dB gain,Yun Wei,UCSB,Yun Wei,common base PA,0.5mm x 0.4 mm,AE=128 mm2,ARO MURI,Bias:Ic=78 mA,Vce=3.6 V f0=85 GHz BW3dB=28 GHzGT=8.5 dBP1dB=14.5 dBmPsat=16dBm,associated gain:4.5 dB,Y.Wei et al,2002 IEEE MTT-S symposium,W band power amplifiers in TS InP DHBT technology,W band power amplifiers in TS InP DHBT technology,UCSB,Yun Wei,cascode PA,0.5mm x 0.4 mm,AE=64 mm2,ARO MURI,Bias:Ic=40 mA,Vce=3.5 V f0=90 GHzBW3dB=20 GHzGT=8.2 dBP1dB=9.5 dBmPsat=12.5 dBm,associated gain:4 dB,Y.Wei et al,2002 IEEE MTT-S symposium,Continuing work,Higher-current DHBTs for increased mm-wave output power250 GHz fmax,Ic,max=240 mA,thermally stable at 200 mA bias at Vce=3.2 Volts suitable for W-band 150 mW power amplifiersW-band DHBT power amplifiersdesigns for 100 mW saturated output power now being testedResults to be reported subsequently,UCSB,Yun Wei,LEC 2002,Conclusions,40 GHz MMIC power amplifier in InP DHBT technology 7 dB power gain and 14 dBm output power at 1 dB compression.17 dBm(50 mW)saturated output power 12.5%peak power added efficiency Future work:higher power DHBT power amplifiers at W-band and abovelumped 4-finger topology,longer emitter fingers,power combiningG-band(140-220 GHz)DHBT power amplifiersAcknowledgementWork funded by ARO-MURI program under contract number PC249806.,UCSB,Yun Wei,LEC 2002,