A 10–230-GHz InP Distributed Amplifier Using Darlington Quadruple-Stacked HBTs

This letter reports a 10–230-GHz indium phosphide (InP) distributed amplifier (DA) using Darlington quadruple-stacked heterojunction bipolar transistors (HBTs). Stacked HBTs are combined with Darlington cells in a DA to achieve a wide output power bandwidth. The Darlington quadruple-stacked DA is fabricated and characterized. The prototype exhibits an average small-signal gain of 12.5 dB from 10 to 230 GHz and output power of higher than 12.5 dBm up to 200 GHz. The peak output power is 17.4 dBm and the 3-dB power bandwidth is from 10 to 180 GHz. The amplifier occupies an area of 0.94 mm2 and consumes 510 mW of dc supply power.