80-GHz distributed amplifiers with transferred-substrate heterojunction bipolar transistors

We report distributed amplifiers with 80 GHz bandwidth and 6.7 dB mid-band gain. These amplifiers were fabricated in the transferred-substrate heterojunction bipolar transistor integrated circuit technology. Transferred-substrate HBT's have very high f/sub max/ (>400 GHz) and have yielded distributed amplifiers with record gain-bandwidth product.