A Self-Adaptively Bandwidth-Adjustable Receiver Analog Front-End for Sensitive Photoacoustic Signal Detection

This letter presents a receiver analog front-end (AFE) circuit specifically for photoacoustic (PA) imaging system. Due to the uncertain nature of the PA signal’s spectrum, this design is proposed featuring multiple bandwidth options that can self-adaptively adjust the loop bandwidth based on the received PA signals in different frequency bands, greatly reducing out-of-band noise and interference. The circuit includes a low-noise amplifier (LNA) and a low-pass filter (LPF), offering four bandwidth options. Frequency detection and bandwidth selection logic are implemented to achieve self-adaptive bandwidth adjustment. The chip is fabricated in a 0.18- $\mu $ m CMOS process with variable gain settings and 4 bandwidth options, achieving 39.5 dB maximum gain, 4 MHz maximum bandwidth, minimum $3.47~\mu $ Vrms input-referred noise and maximum 12.2 mW power consumption, specifically suitable for PA signal detection.