Monolithic ultra-broadband transimpedance amplifiers using AlGaAs/GaAs HBTS

Abstract

Monolithic ultra-broadband transimpedance amplifiers have been developed using AlGaAs/GaAs HBTs (heterojunction bipolar transistors). The amplifiers have exhibited DC to 13.4-GHz bandwidth, with an 18.1-dB gain and a 49.8-dB Omega transimpedance. The standard deviations in gain and 3-dB roll-off bandwidth over 2-in wafers were as small as 0.42 dB and 0.47 GHz, respectively. These results have been brought about by an optimized circuit design that takes into account large signal operation and an affordable HBT fabrication process using a self-aligned method. Excellent 10-GB/s NRZ pulse response has confirmed that the amplifiers are adapted to 10-Gb/s optical transmission systems.< >