Abstract:

A weak signal detection system based on the cross-correlation detection technology is designed and implemented to solve the problem that the pressure sensor output signal is weak and usually mixes with noise and interference.Transformer pressure sensor is used as the pressure signal detection device.Generated by the monolithic integration function signal generator ICL8038,and amplified by the power amplifier TDA7294,the sine wave signal is used as the modulation signal of the sensor signal and the demodulated reference signal of cross-correlation detection.The balanced modulator/demodulator AD630 is used to build the lock-in amplifier.After being amplified,filtered and rectified,a DC signal is obtained.Simulations and experiments show that the system has an ideal effect on the detection of weak signal,and is suitable for the detection of weak signals mixed with strong background noise.

Key words: weak signal detection;lock in amplifier;pressure sensor;ICL8038;AD630