Weak Signal Detection System Based on Lock-in Amplifier Technology
Yong Lv, Chunhui Niu, Yue Qiang Li, Qing Shan Chen, Xiao Ying Li, Zi Ren Zhao · Applied Mechanics and Materials · 2013
In order to detect the weak signal deeply buried in the noise, a weak signal detection system based on lock-in amplifier is proposed. The system includes the preamplifier circuit, active low pass filter circuit, AC amplifying circuit and phase sensitive demodulation circuit. Test results show that it can greatly increase the signal-to-noise ratio (SNR) up to 12.7db.