Broad-band low-noise preamplifier design with GaAs MESFETs for optical communication systems

Classical designs of transimpedance preamplifiers for optical receiver circuits use common-emitter (C-E) or common-source (C-S) input stages. The use of current-mode techniques to design photoreceivers for optical communication systems has been shown to offer significant bandwidth advantages over traditional voltage-mode designs. In this paper, we focus on the design of a wide-band, low-noise photoreceiver in GaAs using current-based amplifying techniques. A 3 dB bandwidth exceeding 3.5 GHz and, 48 dB of gain, along with 12pA//spl radic/(Hz) input noise have been simulated with a photodiode of 350 fF equivalent capacitance. Analysis of simulation results are presented, and a prototype has been sent for fabrication in the TQTRx 0.6 /spl mu/m process from TriQuint Semiconductor's technology.