一种应用于石英音叉增强型光谱的前置放大电路  

Application of a pre-amplifier in quartz enhanced photo-acoustic absorption spectrum

作　　者：常恒泰 常军[1] 刘永宁[1] 王福鹏[1] 王强[1] 

机构地区：[1]山东大学信息科学与工程学院,山东济南250100

出　　处：《山东科学》2014年第2期53-57,共5页Shandong Science

基　　金：国家自然科学基金(60977058);山东大学自主创新基金(IIFSDU2012JC015)

摘　　要：针对目前石英增强光声光谱系统存在音叉输出高阻抗和受噪声辐射影响较大的不利因素,本文设计了一种高输入阻抗、高信噪比的前置放大器。该方案使用高输入阻抗运算放大器,减小音叉两级的信号线长度,使用两路信号相减的方式降低噪音和串接的音叉来提高信号,进一步提高信噪比。并在该放大器的基础上,使用压电陶瓷直接激发音叉的方法精确测量了音叉的共振中心频率和Q值。经实验检验,该放大器模块性能稳定、信噪比高且成本低。We devised a high impedance and high signal to noise ratio （SNR） pre-amplifier for such negatives as tuning fork output of high impedance and stronger adverse noise impact in quartz enhanced photo-acoustic absorption spectrum （QEPAS）.It employed a high input impedance operational amplifier and shorter signal line.Differential input and tuningfork-tandem were used to reduce noise and to improve signal strength.SNR was further increased.We precisely measured the resonance frequency and Q value of the tuning fork with piezoelectric ceramics directly stimulating the tuning fork.Experimental results show that the pre-amplifier has better stability,high SNR and low cost.

关 键 词：石英音叉增强型光谱(QEPAS) 气体检测 前置放大器 

分 类 号：TN722[电子电信—电路与系统]