摘要
针对被噪声淹没的弱信号的检测提出一种基于数字锁定放大器(LIA)的实现方案,该方案将弱信号检测中的数字式平均原理应用于锁定放大器中的滤波器设计,传统的滤波器相比,该滤波器具有结构简单、通带易于调整控制的优点。以检测传感器电路中的弱电压信号为基础建立检测仿真系统,并以Matlab为平台,对方案抑制宽带噪声和单频噪声的性能进行了仿真分析,可以看到,本方案取得了较好的抑制噪声的能力,对于两种不同的噪声污染,当输入信噪比分别为-23 dB和-60 dB时仍可较精确地检测出淹没在噪声中的弱信号幅度。
An implement of detection which based on digital Lock - in Amplifier （LIA） is presented for the weak signal submersed by strong noise,in the scheme, digital average theory is applied to improve design of the filter used in LIA,compared with common filter, the configuration is simple,passband can be adjusted and controlled easier. Simulation system based on the weak voltage signal detection in sensor circuit is established. Matlab is used as a tool to simulate and analyze the scheme＇s ability in restraining wide band and single frequency noise, and better capability to restrain the noise is achieved in this way. It shows that the system still working well when the input SNR is --23 dB and --60 dB for two different noise.
出处
《现代电子技术》
2009年第21期99-101,共3页
Modern Electronics Technique
关键词
弱信号检测
锁定放大
数字式平均
传感器
weak signal detection
lock- in amplifier
digital average theory
sensor
