摘要
针对噪声背景下弱信号检测问题,设计了一种基于锁定放大原理的微弱信号检测系统。该系统基于CD4052模拟开关芯片、LM339比较器与CPLD可编程芯片,包括五个组成部分:微弱信号发生电路、信号调理电路、测频与移相电路、锁定放大电路与模拟-数字转换器。对每部分硬件电路作了详细分析和设计。实验结果显示所设计的弱信号检测系统能检测信噪比为20 d B,幅度10μV微弱信号。
A weak signal detection system based on the principle of locking amplifier was designed for weak signal detection. This system, based on analog switch chip CD4052, LM339 comparator and programmable chip CPLD, consists of five parts: weak signal generating circuit, signal conditioning circuit, frequency detection and phase shift circuit, locking amplifier circuit and analog- digital conversion circuit. Mixed signal was generated by weak signal generating circuit. Signal conditioning circuit, frequency detection and phase shift circuit and locking amplifier circuit was connected. The accuracy of measurement was improved by 16-bit analog-digital converter.
出处
《科技通报》
北大核心
2016年第10期175-179,共5页
Bulletin of Science and Technology
基金
江苏高校优势学科建设工程资助项目
江苏省重点大学生创新项目(201410300023)
江苏省高校自然科学基金(14KJB120007)
大学生创新项目(201610300243)
国家自然科学基金(11504176)
关键词
微弱信号
信号检测
锁定放大
测频移相
可编程电路
weak signal
signal detect
locking amplifier
frequency detection and phase shift
programmable circuit
