90 GHz basedband lumped amplifier
A broadband amplifier using InP/InGaAs single heterojunction bipolar transistor (HBT) is presented. This modified Darlington amplifier exhibits a low-frequency gain of 6.2 dB with –3 dB bandwidth of 90 GHz. This wide bandwidth performance is compatible, or superior to, other lumped or distributed amplifiers based on HEMT and HBT technologies reported in the literature.