RF Characterization and Gated-Mode Drive Optimization of High-Reverse-Bias Silicon APDs in the Solar-Blind Ultraviolet Band

Silicon avalanche photodiodes (Si-APDs) operated in gated mode require high peak-to-peak voltages for effective avalanche triggering and lack of corresponding RF models. To address this, we propose a S-parameter measurement method for accurate RF characterization from 100 MHz to 13.6 GHz. Based on the extracted data, we design a matched amplifier network and propose an algorithm to calculate the voltage across the APD, achieving 42 V crossing the APD with only a 27.5dBm amplifier at 600 MHz. The 50 Ω-optimized design improves coupling efficiency, harmonic suppression capability, and reduces gating jitter to 1.7%. This provides technical support for reducing design costs and improving the stability of high-performance single-photon detection systems.