光声光谱仪微弱信号检测电路的低噪声设计  

Low Noise Design of Weak Signal Detecting Circuit for Photo-acoustic Spectrometer

作　　者：赵彦东[1] 方勇华[1] 刘家祥[1] 王安静[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所,通用光学定标与表征技术重点实验室,安徽合肥230031

出　　处：《压电与声光》2015年第1期149-153,共5页Piezoelectrics & Acoustooptics

摘　　要：光声光谱技术在变电站SF6气体分解产物,医疗诊断等场合的微量气体检测方面有着高灵敏度的特点。根据低噪声电子设计理论,设计了基于光声光谱探测技术的低噪声检测电路;从整个系统的角度出发,通过噪声模型对系统噪声和信噪比进行计算,对电路进行分析并使用集成运算放大器设计前置放大电路和信号调理电路。实验测试结果表明,该检测电路可稳定的将光谱仪的光声信号转换为电信号,电路信噪比高,可靠性高且稳定性高。Photo-acoustic spectroscopy technology is increasingly used for its high sensitivity characteristics in the detection of SF6 decomposition in substations and medical diagnosis.A kind of low noise design of weak signal detecting circuit is designed.According to the model of noise analysis,the system total noise and SNR are calculated based on the theory of low noise design.Then the pre-amplify circuit and signal conditioning circuit are designed based on the analysis of the operation amplifiers.The experimental results show the detection circuit can translate the photo-acoustic signal to the electric signal steadily,which has the high SNR,high reliability and high stability.

关 键 词：光声光谱 微弱信号 前置放大 低噪声 噪声模型 

分 类 号：TN722.3[电子电信—电路与系统]