Simple approach to design optimum noise-matching networks for optical receivers

Abstract

A simple design approach to synthesize the elements of the optimum noise‐matching networks for optical receivers is presented. The developed design approach utilizes noise figure data for the MESFET transistor of the transimpedance amplifier and the elements of a simple equivalent circuit of the photodiode. Although the technique is presented for an inductive T‐network, it can be easily extended to a general noise‐matching network. The design principles are verified with an experimental 2.5 Gbit/s coherent optical receiver implemented with two commercial p‐i‐n photodiodes and a full custom‐designed GaAs MMIC transimpedance amplifier. A transimpedance of 63 dBΩ in a band from 1.5 to 7 GHz with a flatness of ±1.5 dB and average noise current density of has been measured.