激光差动多普勒的信号处理电路设计

随着微机电系统(MEMS)技术的迅速发展,对器件运动性能检测的需求日益迫切.采用激光差动多普勒测量技术能准确可靠地对MEMS器件进行动态特性测试.本文介绍了激光差动多普勒系统的信号处理电路的设计,主要包括放大电路、相敏检波电路和滤波电路.放大电路能将40 MHz频率信号放大100倍,相敏检波电路滤除了高频信号,分离出多普勒频移信号,滤波电路进一步滤除相敏检波电路输出信号中的载波信号和高频噪声.本电路设计最终实现了从光路系统输出的高频信号中提取多普勒信号.

Design of differential laser Doppler signal process circuit

With the development of the MEMS,the testing requirement of devices' motion capability is urgent.The differential laser Doppler technique is credible to be adopted for dynamic testing.In the paper,design of signal circuit in the differential laser Doppler system is introduced,which includes amplifier,phase-sensitive detector and filter circuit.The amplifier circuit can magnify 100-times of the 40MHz frequency signal;the phase-sensitive detector circuit filtrates high frequency signal,retraces the Doppler frequency signal,and meanwhile the filter circuit eliminates the carrier wave and high frequency signal output from phase-sensitive detector circuit.The whole system fulfills the objective to extract Doppler signal from the high frequency output signal of optical system.