CLASS-A SIGE HBT POWER-AMPLIFIERS AT C-BAND FREQUENCIES

In this letter we report on the first experimental investigations of t he power-handling capabilities of SiGe heterojunction bipolar transist ors (HBT's) at C-band frequencies. Multifinger HBT's in common-emitter (CE) and common-base (CB) configuration were matched using high Q mat ching networks. At a frequency of 5.7 GHz the CE and the CB class A am plifier exhibit a 1-dB compression output power of 18 and 20 dBm, resp ectively. A power-added efficiency (PAE) of more than 30% and a output power density of 1 mW/mu m(2) at 4 V V-CB were observed.