50-GHz-bandwidth baseband amplifiers using GaAs-based HBTs

Abstract

Baseband amplifiers of 50 GHz, using high-performance AlGaAs/InGaAs HBTs with regrown base contacts, have been demonstrated. The transimpedance amplifier achieved a bandwidth of 50.8 GHz with a gain of 11.6 dB. The transimpedance characteristics were of 49.3-GHz bandwidth with a 43.7-dB/spl Omega/ transimpedance gain. The resistive and mirror Darlington feedback amplifiers, respectively, achieved a bandwidth of 54.7 GHz with a gain of 8.2 dB and a bandwidth of more than 60.0 GHz with a gain of 6.3 dB. To date, these are the widest bandwidths reported for lumped-circuit-design amplifiers. These results suggest the great potential of these amplifiers for use in future optical communication, microwave and millimeter-wave applications.