1. Y. Wei, M. Urteaga, Z. Griffith, D. Scott, S. Xie, V. Paidi, N. Parthasarathy, M. Rodwell. Department of Electrical and Computer Engineering, University of California, Santa Barbara yunwei@ece.ucsb.edu 1-805-893-8044 IMS2003 June 2003, Philadelphia, PA 75 GHz 80 mW InP DHBT Power Amplifier

2. W-band MMIC power AmplifiersIMS2003 Applications for electronics in 75-110 GHz frequency band Wideband communication systems, Atmospheric sensing, Automotive radar 2 stage 94 GHz 0.15  m InP HEMT power amplifier: P out = 316 mW Y.C.Chen et. Al. IPRM, May 1999 Cascode 78 GHz InAlAs SHBT power amplifier: P out = 12 mW J. Guthrie et. Al, IPRM, May 2000 Single stage 85 GHz InP DHBT power amplifiers: P out = 40 mW Y. Wei et. Al, IMS, June 2002 This work Single stage 75 GHz HBT power amplifiers: Pout= 80 mW Transferred substrate InP/InGaAs/InP DHBT Highest Reported Power for HBTs in W-band UCSB Yun Wei

3. Transferred substrate HBT technology IMS2003 ε=2.7 UCSB Yun Wei Gains are high at 220 GHz, but f max can’t be extrapolated M. Urteaga

4. InP TS DHBT: A E =0.4 x 7.5  m 2, A C =1.0 x 8.75  m 2, J C =1.8 mA/  m 2, V BR,CEO = 8 V f max = 460 GHz, f t = 139 GHz, S. Lee DRC2002 InAlAs/InGaAs TS HBTs: 0.3  m Three-stage amplifier designs: 8.5 dB gain at 195 GHz, M. Urteaga GaAs IC 2002 Submicron transferred-substrate HBTs and amplifier IMS2003 UCSB Yun Wei

5. IMS2003 UCSB Yun Wei 8 x ( 1  m x 16  m emitter ) 8 x ( 2  m x 20  m collector ) V br_ceo >7 V, I max =130mA f0=85 GHz, BW 3-dB =28 GHz, G T =8.5 dB P 1-dB =14.5 dBm, P sat =16dBm Transferred substrate power HBT and amplifier (IMS2002)

6. IcIc f1 f2 f3 f4 4-emitter-finger HBT topology JcJc Multiple finger thermal instability- Current Hogging Long finger thermal instability Thermal instability in power HBTs IMS2003 UCSB Yun Wei HBT thermal stability factor

7. Band profile Bias at Vbe=0.7 V, Vce=1.5 V Long emitter ballasting: Lightly doped emitter expitaxy * u n =2000cm 2 /V.S LDE doping level must not limit maximum current density  LDE resistance  emitter cap InGaAs 1x10 19, 300 Å InGaAs/InAlAs 2x10 19, 90 Å InP 5x10 16, 1000 Å InP 8x10 17, 300 Å grade LDE emitter emitter emitter contact Ti/Pt/Au IMS2003 UCSB Yun Wei

8. 1/4 Amp, 220 GHz f max InP Power DHBT UCSB Yun Wei 192  m 2 common base LDE DHBT 8 x ( 1  m x 24  m emitter ) 8 x ( 2  m x 28  m collector ) ~8 Ohm ballast per emitter finger f max >230 GHz V BR_CE >7 V I max =250mA Optimum load bias condition I c =140 mA, V ce =3.7 V IMS2003 I E step=50 mA

9. Common-base, optimum load match 8 dB gain, 21 dBm output power self-developed multi- finger large signal HBT model with thermal effects electromagnetic simulation of all passive elements (Agilent Momentum) Amplifier Design IMS2003 UCSB Yun Wei

10. Amplifier Measurements f 0 =75 GHz, G T =5.6 dB P 1-dB =18 dBm, P sat =19 dBm @ 4dB gain Device dimensions:  Emitter area: 1x16x16=256  m 2  Collector area: 2x20x16=640  m 2 Device bias conditions:  I c =130 mA, V ce =4.5 V Small signal measurement Large signal measurement IMS2003 Die size: 0.38 mm  0.89 mm UCSB Yun Wei

11. Conclusions Demonstrated Wideband Power DHBT: I c_max > 240 mA, V ce_BR >7 V, f max =300 GHz Wideband Power amplifiers: f 0 =75 GHz, G T =5.6 dB, P sat =19dBm Multi-finger emitter ballasting scheme provides direction for future high power and high frequency MMIC work in transferred-substrate process Future work Multi-stage wideband high power amplifiers ~200 GHz power amplifiers Acknowledgements This work is funded by ARO-MURI program under contract number PC249806. UCSB Yun Wei IMS2003