A monolithic HBT-regulated HEMT LNA by selective MBE

We demonstrate here the monolithic integration of an HBT operational amplifier and a HEMT low-noise amplifier to achieve an elegant single-chip solution to the problem of HEMT current regulation. We have developed a novel method of achieving monolithic HEMT-HBT integration by selective MBE and a unique merged-processing technology. Pseudomorphic 0.2 μm gate-length InGaAs-GaAs-AlGaAs HEMT's and 2×10 μm2 GaAs-AlGaAs-InGaAs HBT devices have been incorporated into the same microwave circuit for the first time with no degradation in the intrinsic device performance of either device technology.