OPTIMIZED GATE-DRAIN FEEDBACK CAPACITANCE OF W-BAND HIGH-GAIN PASSIVATED 0.15-MU-M INALAS INGAAS HEMTS/

A 0.15 mu m high gain, passivated, double-side-doped InAlAs/InGaAs HEM T with high uniformity over 2 in InP substrates has been developed. A measured gain of 12.5 dB at 94 GHz was achieved at a drain bias of 2 V , giving an f(max) exceeding 400 GHz. This high gain is mainly related to the extremely low gate-drain Feedback capacitance, for which the p hysical origins will be demonstrated. Using this technology, a single stage amplifier with 10.3 dB gain at 88 GHz and a distributed amplifie r with 11 dB gain and 89 GHz bandwidth were fabricated.