Infrared detector signal modulation and narrow band filter system and realization method

The invention discloses an infrared detector signal modulation and narrow band filter system and a realization method. The system comprises a sinusoidal signal generator, an analog multiplier and a bandpass filter. Output of the sinusoidal signal generator in the system is connected with input of the analog multiplier, and output of the analog multiplier is connected with input of the bandpass filter. The infrared detector signal modulation and narrow band filter system and the realization method have the advantages that amplitude information of signals outputted by the infrared detector can be obtained, noise is reduced greatly, and the signal to noise ratio of the infrared system is thus improved.