A 64 ?dB?, 25 ?Gb/s GFET based transimpedance amplifier with UWB resonator for optical radar detection in medical applications

Abstract

This work reports a novel Graphene Field Effect Transistor (GFET) based transimpedance amplifier (TIA) for optical radar detection in medical applications. Design-I includes a microstrip line (MSL) based UWB resonator circuit which enables the TIA design to operate in UWB range of frequency with high Q-factor. Design-II comprises MSL UWB resonator integrated stagger-tuned CR-RGC TIA which enhances the transimpedance limit and mitigates the effect of photodiode capacitance results in higher bandwidth performance. The proposed TIA realizes a 2.6 times lesser noise compared to the conventional CR-RGC TIA. A flat transimpedance gain of 64 ?dB? and ultra-low input-referred noise current density of 8.9 pA/?Hz are achieved using gain and noise optimization methods. Additionally, a dynamic range of 49 ?dB with a group delay variation (GDV) of ±25 ps is achieved over the entire UWB range. The TIA demonstrates a 25 ?Gb/s data rate while a bit-error-rate (BER) less than 10?10 is achieved. The chip occupies an area of 0.67?0.72 ?mm2 while consuming power of 19 ?mW under the supply voltage of 1.8 ?V. © 2021 Elsevier Ltd