A Study on the Design of a P-Band Photoelectric Signal Conversion Circuit

As one of the core modules in the Radio over Fiber (ROF) system, the performance of an optical receiver module plays an important role in the overall communication quality. This paper presents the design of a single-channel RF optical receiver module for ROF applications, which incorporates a boost driver circuit, a transimpedance amplifier with a feedback system, a twostage cascaded main amplifier circuit, and an impedance matching circuit. The design enables linear adjustment of the detector's bias voltage between <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$25 \mathrm{V} \sim 175 \mathrm{V}$</tex>. By optimizing the transimpedance amplifier circuit and designing the main amplifier circuit, the module's passband is extended to 240MHz, and the transimpedance gain is increased to 79.7dB. When the photocurrent is below 32μA, the system's total harmonic distortion (THD) is less than 10%, demonstrating good circuit stability. Finally, we constructed a complete photodetection system and conducted experiments using semiconductor laser diodes (LD) and avalanche photodiodes (APD). The results show that the module can effectively recover and amplify the original RF signal with minimal distortion, providing a complete sine wave signal throughout the link system.