高速光电探测器阵列实时信号处理系统

Real-Time Signal Processing System for High Speed PIN Photodiode Array

高速光电探测器阵列可对脉冲辐射场的时空分布进行高时间分辨连续测量,但对信号处理电路的性能和紧凑性提出了极为苛刻的要求。探测器阵列的信号处理主要包括探测器模拟信号调理前端和高速模拟信号实时采样处理后端。针对32通道1维光电探测器阵列,设计实现了后端实时信号处理系统。该系统采用多通道高速ADC和FPGA实现了探测器模拟信号的12bit量化,采样频率为75 MHz;针对多通道ADC输出的高速串行信号,设计实现了低开销的时钟对齐与帧识别电路,时钟对齐精度为78ps,保证了对多路高速串行数据的正确获取;基于高性能FPGA,实现了对32个采样通道数据的实时处理与存储,信号处理电路的数据获取和实时处理速度达28.8Gb/s。

High speed PIN photodiode array is used for high precision measurement of spatial-temporal distribution of pulse radiation field, but it requires an extremely high perform ance and compact signal processing circuit. Signal processing of photodiode array mainly include a signal conditioning frontend of the analog outputs and a high speed real-time signal processing backend. Aiming at a 32 channels one-dimensional PIN array, we designed and implemented a real-time signal processing circuit of 16 cm wide. The signal is sampled at 75 MHz and quantized at 12 bits. We also designed a low cost bit clock alignment and frame recognition circuit for high speed serial output signal of muhi channel ADCs. The time precision of the clock alignment is 78 ps, which guarantees the correctness of the high speed serial data acquisition. Real time data processing and catching of 32 sampling channels are imple mented based on high performance FPGA. The bandwidth of data processing and catching reaches up to 28.8 Gb/s.