A Low-power, CMOS Optical Communication Receiver System for 5Gbps Applications based on RGC Structure

Abstract

An optical communication receiver system is presented in this research using 65nm CMOS, which consists of three lowpower active differential stages as Limiting Amplifier (LA) following an ultra-low-power RGC-Based Transimpedance Amplifier (RB-TIA). The presented active circuit of the RB-TIA is followed by a gain stage that extends the -3dB frequency of the circuit by creating a resonance for the load capacitance. Thus, needless of consuming extra power, a wide-bandwidth circuit has been designed. In addition, employing active-inductor loads within the LA stages enables obtaining a 5Gbps receiver system. The RB-TIA consumes 573µW and provides 3.52GHz frequency, while the complete optical receiver consumes only 4.76mW power to provide -3dB frequency of 3.5GHz and high gain of 80dB (10’000). The circuits have been mathematically presented and discussed, and simulations have justified the presented circuit design.