Gorre, P.Vignesh, R.Kumar, S.Song, H.Roy, G.M.2026-02-042023International Journal of Circuit Theory and Applications, 2023, 51, 2, pp. 912-931989886https://doi.org/10.1002/cta.3471https://idr.nitk.ac.in/handle/123456789/22052Recent advancements in the area of telemedicine have focused on remote patient monitoring services as a new frontier in medical applications. The present work reports a 65-nm complementary metal–oxide–semiconductor (CMOS)-based transimpedance amplifier (TIA) in an optical radar system for non-contact patient monitoring. A T-shaped microstrip line (MSL) integrated with variable gain common source TIA using MSL peaking technique and off-chip post-amplification integration is a newly proposed architecture to achieve a ultra-low noise, high dynamic range (DR) and high figure of merit over broadband than a traditional TIAs. First, the integrated T-shaped MSL develops an additional resonant frequency that resonates with a photodiode capacitance improving the bandwidth performance at higher Q values. Second, the shunt MSL peaking technique that introduces an additional conjugate pole-pair that cancels the effect of input capacitance helps to further improve the bandwidth of the TIA. Finally, an active feedback concept achieves a wide linear dynamic range enabling high TIA detectability. The proposed TIA realizes an impedance bandwidth of 770 MHz ranging from 7.12 to 7.89 GHz with a transimpedance gain of 105.1 dBΩ and ultra-low input-referred noise (IRN) density of 2.71 pA/√Hz. A high linear DR of 70 dB is achieved by employing a variable gain control scheme with a low group delay variation of 0.81 ns. The proposed work demonstrates a 1-Gb/s data rate while a bit-error rate less than 10−12 is achieved. The TIA consumes a power of 0.82 mW under the supply voltage of 1.2 V. © 2022 John Wiley & Sons Ltd.BandwidthBit error rateCapacitanceCapacitive sensorsElectric impedanceGroup delayMedical applicationsMicrostrip linesNatural frequenciesOperational amplifiersRadarBERComplementary metal oxide semiconductorsLinear dynamic rangesMicrostrip lineMicrostrip-lineOptical radar systemPeaking techniqueT-shaped microstripTransimpedance amplifierUltra low noiseCMOS integrated circuits