Surface Acoustic Wave (saw) Sensor Circuit Integrated Design

Surface acoustic wave (SAW) sensor is more and more concerned because it has the advantages of small size, high sensitivity and low cost. Designing of the integrated circuit system is directly related to the accuracy and stability of the sensor, so research on optimizing the integrated circuit system is very important.By analyzing the operating principles of the SAW sensor and the detection circuit, studying the SAW sensor whose center of the resonant frequency is 433.92MHz, designing the filter, mixer and shaping circuit with a structure of dual-channel, and simulating the circuits. The signal of dual-channel is proceeded by a mixer and shaped by the shaping circuit, and finally is transformed to logic level to be the input signal of the back-end detection circuit. Set the frequency deviation as the input signal, simulated the circuits, and the results show that the frequency detection circuit can detect and display the information to be measured, and the error is less than 0.05%, which meets the accuracy requirements of the SAW sensor. Finally the whole circuit of SAW sensor is designed and the integrated system of a SAW sensor is achieved.