A 150-MHz Bandwidth and 39-dBm OOB-IIP3 Transimpedance Amplifier with Feedforward Compensation and Second-Order Rauch Filtering

This paper presents a wideband transimpedance amplifier (TIA) with high linearity and power efficiency, which is suitable for Sub- 6 GHz surface acoustic wave (SAW) filter-less receivers. In this work, the TIA employs a Rauch biquad filtering topology, effectively enhancing the out-of-band (OOB) selectivity. The core circuit of the TIA is a high unity-gain bandwidth operational amplifier (OpAmp). To ensure the stability of the OpAmp, a feedforward stage is introduced to further increase the phase margin. Additionally, a current-reuse technique is applied in the FF stage to enhance the power efficiency of the TIA. With a power dissipation of 12 mW at a 1.2-V voltage supply, the proposed TIA achieves an OOB-IIP3 of 39 dBm, a bandwidth of 150 MHz, and an in-band input referred noise of $33.3 \mu V_{RMS}$.