摘要
提出了采用双相正交数字相敏检波(DPSD)方案设计数字锁相放大器(DLIA)代替传统模拟锁相放大器,并应用到了真空镀膜光学监控系统(OMS)中。针对信噪比(SNRI)和相位延时对方案进行了仿真分析。结果证实了双相正交PSD方案的可行性。由于在输入信号采样频率一定时,OMS精度和实时性之间存在矛盾关系,所以应尽量提高输入信号采样频率以获得高的SNRI。在DLIA中采用低阶滤波器和较高截止频率还可以减轻输出波形过冲效应的影响。
A digital lock-in amplifier(DLIA)is advanced based on the scheme of orthogonal digital phase-sensitive detector(DPSD),which is applied to optical monitor system(OMS)instead of traditional analog lock-in amplifier.Aimming at signal-to-noise improving(SNRI)and phase delay time,the acheme is emulated and analyzed.As a result,the feasibility of scheme is approved.When the sampling frequence of input signal is invariable,the precision and real-time performance is inconsistent.Therefor,to get high SNRI,the sampling frequence of input signal must be increased.Adoptting low-order filter and high cut-off frequence can alleviate rush effection of output wave.
出处
《光学技术》
CAS
CSCD
北大核心
2006年第z1期232-235,共4页
Optical Technique
