Small- and large-signal operation of X-band CE and CB SiGe/Si power HBT's

Common-emitter (CE) and common-base (CB) multifinger SiGe/Si power heterojunction bipolar transistors (HBTs) for X-band operation are reported for the first time. 10-finger CB and CE devices show f/sub max/ of 28 GHz and 20 GHz, maximum PAE of 34.9% and 17.5%, and P/sub out/ at 1 dB gain compression point of 15.6 dBm and 17.5 dBm, respectively, in class A operation at 8 GHz for CW mode.