40 GHz transimpedance amplifier with differential outputs using InP/InGaAs heterojunction bipolar transistors

High gain and bandwidth transimpedance amplifiers (TIA) are required for fiber optic receiver modules. This paper reports on the design, fabrication and characterization of a 40 Gbit/s TIA for SONET/SDH STS-768/STM-256 applications based on an InP/InGaAs single heterojunction bipolar transistor (SHBT) process developed at Vitesse Semiconductor Corporation (Vitesse Indium Phosphide Release 1 or VIP-1). This amplifier consists of a single-ended input transimpedance pre-amplifier and a differential output post-amplifier. The measured differential transimpedance is 1800 /spl Omega/ with -3dB bandwidth greater than 40 GHz. The high gain of this circuit eliminates the need for a stand-alone limiting amplifier between the conventional transimpedance pre-amplifier and the demultiplexer (DMUX) in short reach applications.