High efficiency X-band power HBTs

High-efficiency X-band power GaAs-AlGaAs HBT (heterojunction bipolar transistor) performance has been achieved. A common-base 6-emitter-finger HBT device (each finger periphery 2 mu m*20 mu m) exhibited a power-added-efficiency of 62.1%, an output power of 769 mW (power density of 6.4 W/mm), and a gain of 7.9 dB at 9 GHz. As compared to the published state-of-the-art results, this device showed better power efficiency and density at the same output power level. This high performance is attributed to process enhancement and a novel device topology.<>