FINE SIGNAL DETECTOR

摘要

Disclosed is a fine signal detector. A reference signal generation unit generates and outputs a reference signal that has the same frequency as a signal to be detected which is included in an input signal. A frequency mixing unit multiplies the input signal by the reference signal and generates a synthesis signal. A filtering part extracts from the synthesis signal a signal corresponding to a second harmonic component with respect to the frequency of the signal to be detected. A signal detection unit detects a signal to be detected from the signal that is output by the filtering unit. By selectively detecting either a direct current component or a harmonic component among the components that are obtained by multiplying the input signal by the reference signal having the same frequency as the signal to be detected, the present invention enables effective suppression of noise that impacts signal detection, thereby enhancing the detection sensibility of fine signals.