Design, simulation and performance analysis of a 40 Gbps transimpedance amplifier for optical fiber links

Abstract

This paper presents the design of a 40 Gbps BiCMOS transimpedance amplifier for use as the front-end preamplifier stage of an optical communication receiver system. The design is modeled using Pspice. Stability is achieved using a shunt-shunt feedback circuit. This feedback circuit is also used to improve the bandwidth of the amplifier. A shunt inductor peaking technique is used to further extend the bandwidth. Analytical expressions were developed for the transfer functions of the input stage, output stage and the overall amplifier. Frequency response curves were obtained for each stage using MATLAB. The performance of the designed amplifier was analyzed and evaluated with respect to gain, bandwidth and noise using developed analytical models and Pspice simulation results. This amplifier is stable, provides good gain and should be suitable for OC-768 SONET applications.