A Rapid Weak Signal Detection Approach in Resonant Pressure Sensors

In this paper, a rapid detection method for weak signal detection is proposed in resonant pressure sensors. The method is based on cross-correlation with a dedicated phase sensitive detector (PSD) and an improved integrator. The PSD is the sensitive resistor which is an ideal analog multiplier based on Ohm's law. The AC voltage applied to the resistor is modulated by square wave so that the input of improved integrator is signal with alternate inverting phase. The low frequency noise is proved to be eliminated via difference of integrator output and the high frequency noise can be suppressed efficaciously by linear fit. The prototype is made and the experiment results show that the rapid cross-correlation detection has larger signal noise improvement ratio (SNIR) even though its measurement time is 1/25 of the traditional LIA.