用于痕量检测微弱信号提取的锁相放大电路设计及实现  

Design of a Lock-in Amplifier Circuit and Its Application in a Trace Gas Sensor

作　　者：倪家升[1,2] 刘统玉[1] 王昌[1] 常军[1,2] 宋志强[1] 王黔[1] 刘真梅[1] 翟瑞占[1] 

机构地区：[1]山东省科学院激光研究所山东省光纤传感技术重点实验室,山东济南250014 [2]山东大学信息科学与工程学院,山东济南250100

出　　处：《山东科学》2009年第5期48-52,56,共6页Shandong Science

基　　金：国家科技支撑计划项目(2006BAK03B00);山东省科技攻关项目(2009GG10007016);山东省重大专项项目(2008ZHZX1A0308)

摘　　要：在分析了现代微弱信号检测的研究技术的基础上,设计了一种基于AD630芯片的锁相放大器电路,利用锁相放大器芯片内部的锁相与乘法功能,对参考信号与探测信号进行处理,实现了信号的锁相放大,通过合适的积分电路,实现了锁相放大器的设计。文章还对微弱信号的前置放大电路进行设计,从而提高了整个锁相放大器电路的整体性能。该电路成功应用于光纤痕量气体检测中,并实现了0.0001%浓度量级的一氧化碳痕量检测,提高了检测灵敏度,效果明显。We designed an AD630 based lock-in amplifier circuit. We employed the phase-locked and multiplication functionalities of AD630 to process the reference and detection signal and realized the phase lock of a signal. We further obtained a lock-in amplifier by AD630 and an appropriate integration circuit. We also devised a preamplifier circuit for a weak signal, by which the global performance of the amplifier circuit is improved. We successfully applied the circuit to the optical detection of trace gases. It can detect carbon monoxide of 0. 0001% concentration. Results show that the circuit significantly improves the sensitivity of trace gases detection.

关 键 词：微弱信号 痕量气体检测 电路 锁相放大器 

分 类 号：TN911.8[电子电信—通信与信息系统]