锁相放大器直流输出分析——输入占空比可调矩形波信号  

Study on DC output of lock-in amplifier with duty cycles rectangle wave as signal source

作　　者：张国浩[1] 陈宜保[2] 张晓平[2] 

机构地区：[1]清华大学工程物理系,北京100084 [2]清华大学物理系,北京100084

出　　处：《中国测试》2011年第6期91-93,共3页China Measurement & Test

摘　　要：锁相放大器在微弱信号检测中具有广泛的应用,为了更好地了解锁相放大器的工作特性,采用占空比可调的矩形波信号作为信号源输入,系统研究锁相放大器的直流输出与输入信号的相位及占空比的关系。实验结果表明:采用幅值相同、不同占空比的矩形波信号通过锁相放大器其直流输出值不同,输入不同占空比的矩形波的被测信号在锁相放大器直流输出与相位和占空比的关系图像为三角波形,当占空比为0.5时有最大输出值。Lock-in amplifiers have been widely applied to weak signal detections and measurements.The purpose of this research is to further understand the principal and its characteristics of lock-in amplifier.When taking the rectangle wave as the signal source,the authors study the DC output from a lock-in amplifier in various duty cycles.Results show that using rectangle wave as input signal with identical amplitude,the DC output in various duty cycles is different.Both the DC output vs.the duty cycle of the rectangle wave and the phase are triangle waveform.The DC output is the maximum at 0.5.

关 键 词：锁相放大器 矩形波 直流输出 占空比 三角波 

分 类 号：TN911.23[电子电信—通信与信息系统] TM930.12[电子电信—信息与通信工程]