红外光谱仪中微弱信号检测电路的低噪声设计  

Low Noise Design of Weak Signal Detecting Circuit in IR Spectrometer

作　　者：张洋[1] 张记龙[1,2] 杜宣燕[3] 

机构地区：[1]山西省光电信息与仪器工程技术研究中心,山西太原030051 [2]中北大学仪器科学与动态测试教育部重点实验室,山西太原030051 [3]中北大学机电工程学院,山西太原030051

出　　处：《压电与声光》2011年第4期674-678,共5页Piezoelectrics & Acoustooptics

基　　金：科技部国际合作基金资助项目(2010DFR10520);山西省国际合作计划基金资助项目(2010081038);山西省科技攻关基金资助项目(20090321044);山西省科技平台建设基金资助项目(2010091013);山西省研究生优秀创新基金资助项目(20081017)

摘　　要：被动式傅里叶变换红外光谱(FTIR)遥感技术越来越多的应用在开放环境中探测目标化合物和气相鉴定,该文设计了基于HgCdTe光电导型红外探测器的红外信号检测电路,该电路在红外遥感系统中用作信号调理,具有高信噪比、高灵敏度的工作特性。根据探测器接收干涉光后输出的微弱电信号来设计微分电路和二级放大电路,运用标准的电路理论为检测电路建立等效噪声模型,通过叠加法计算出电路输出端总的电压噪声和信噪比,最后从工程设计角度提出了抑制噪声的方法。实验结果表明,检测电路在室温,一个标准大气压下能稳定的输出大气干涉红外光转换成的电信号,可实现对大气的红外遥测。Passive FTIR remote sensing technology is increasingly used for target compounds exploration and gas identifying in an open environment. The IR signal detecting circuit is based on HgCdTe photoconductive IR detectnr, which is used as a high SNR with high sensitivity performance characteristics. After receiving and transfer ring interference light to the weak current of the output signal of detector, the differential circuit and the secondary amplifier circuit is designed. Using the theory of standard circuit for the equivalent noisy model, the circuit superpo sition method can be used to calculate the total noise of output voltage and SNR. Experiments with a standard atmospheric pressure and a room temperature show the feasibility of stable output of electrical signals which is converted by the atmospheric IR interference light; and the IR remote sensing of atmospheric can be realized.

关 键 词：检测电路 微弱信号 等效噪声模型 信噪比 

分 类 号：TN702[电子电信—电路与系统]