基于锁相放大技术的激光超声信号处理电路的设计  

Design of signal processing circuit of laser ultrasonic based on phase lock-in amplifier technology

作　　者：金宝印[1] Dante Dorantes 白茂森[1] 孙凤鸣[1] 李艳宁[1] 陈治[1] 胡小唐[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《传感器与微系统》2012年第3期109-112,共4页Transducer and Microsystem Technologies

摘　　要：利用激光声表面波(SAW)技术对膜材料机械特性的测量(如杨氏模量、密度、厚度等)已得到了越来越广泛的应用。但激光激发激光检测声表面波(LG/LD-SAW)的频谱带宽较宽(达几百兆到GHz),一般的检测方法难以在如此高的带宽下对其进行检测。设计了一种基于锁相放大(LIA)原理的微弱信号处理电路,通过应用一特殊的去噪电路,能在很宽的频谱(GHz)范围检测微弱信号,并将其从噪声信号中提取出来。Laser surface acoustic wave（SAW） technology for measuring thin film mechanical properties such as Young＇ s modulus, density, thickness,and so on,has been widely used. However, due to wide spectrum bandwidth （up to several hundred MHz to GHz） of laser-generate and laser-detecting surface acoustic wave（LG/LD-SAW） , general methods can not detect it in such a high bandwidth. A weak signal processing qircuit based on lock-in amplifier（LIA） is proposed, and it achieves GHz detection of weak signals through using a special de-noising circuit and it can be extracted from noise signal.

关 键 词：激光声表面波 锁相放大 微弱信号 

分 类 号：TB523[理学—物理]