Ku-band (12.6GHz) SiGe/Si high-power heterojunction bipolar transistors

Large-area multifinger Si sub(0.7)Ge sub(0.3)/Si heterojunction bipolar transistors for high-power and high-frequency operation have been designed, fabricated and characterised. For a nine-emitter finger device, an f sub(max) of 100 GHz was achieved with a maximum available gain of 14 dB. The peak power-added efficiency in the Ku-band (12.6GHz) in the common-base configuration for a 15-emitter finger device was 23% with associated power gain of 7.4 dB and an output power of 22 dBm under class AB operation. The device delivered a maximum output power of 24.4 dBm under the same matching conditions.