基于Filterlab的一种高指标带通滤波器的设计

摘要

为了提取激光外差玻璃测厚系统中的微弱信号，介绍了激光外差玻璃厚度测量系统原理及待检测信号特征，采用一种简洁、实用的滤波软件，设计出一种高指标带通滤波器，从滤波器频谱图看待检测的激光外差信号频谱完全在通频带内，噪声衰减带达到80dB，其完全符合系统要求。%To extract the faint signal in the system of Glass-thickness measure using laser heterodyne, this article introduces the principle of Glass-thickness measure using laser heterodyne and the feature of awaiting inspection signal. It uses a kind of brief and practical filter Fiterlab software and designs a kind of bandpass filter with high target. The Spectrum of awaiting laser heterodyne signal is completely in the bandwidth, observing through the diagram of filter Spectrum, which can cut down noises to 80dB, therefore it can completely accord with the demands in the system.