A Detection Circuit to Faint Signal for Difference Absorption Gas Sensor
In gas difference absorption detecting system, the output electric signal is very faint and submerged in the background noise. In order to extract the faint signal covered by the background noise, we design the detective circuit aiming at how to restrain the noise and improve SNR of the system. In this paper, the detection circuit centering lockin amplifier which reference signal frequency is automaticly followed is designed. The circuit adopts synchronization cumulating and locked loop technic, carries out frequency and phase aotomatic follow to the measuring signal by a locked loop circuit. The circuit not only avoids the tache taking reference signai from the modulator then adjusting the phaseshif, but also improving signal-to-noise ratio more by synchronization cumulation.
lock-in amplifier faint signal signal-to-noise ratio synchronization cumulation locked loop
Wang Yanju Chen Jiaxing Kang Yueyi YangLikun Wang Yutian
HeBei Normal University, Shijiazhuang,050031 HeBei Normal University,Shijiazhuang, 050031 HeBei Normal University, Shijiazhuang, 050031 Institute of electric engineering, YanShan University.Qinhuangdao, 066004
国际会议
三亚
英文
446-449
2012-01-06（万方平台首次上网日期，不代表论文的发表时间）