The Vector Measuring of Weak Signal Based on Dual-Phase LIA
Yong Kui Cai · Microcomputer Information · 2007
Noise exists in all systems,especially it is difficult to detect weak signal in strong noise based on conventional ways,so more attention has been paid to the problem of how to measure the weak signal in strong noise .The principle and process of detect-ing weak signal by using Lock-in amplifier are discussed in details in the paper .Two orthogonal square waves as referential waves are got by hardware phase shift.and realized an orthogonal vectors LIA by using cross correlation algorithm.It is effective on restrain-ing noise to get amplitude and phase of weak signal in noise.