Design and Simulation of a Novel Wireless Passive SAW Soil Pressure Sensor

A novel wireless passive SAW (Surface Acoustic Wave) soil pressure sensor based on delay line theory is designed in this paper. The principle of the sensor is described, and also the mechanical properties analysis and Finite Element Simulation analysis about the piezoelectric substrate is done to verify the effectiveness of the sensor. With hollow cylindrical bottom sealing piezoelectric substrate, and not involving electron mobility inside the crystal, the sensor is immune to electromagnetic interference factors; moreover the piezoelectric substrate adopts ST-X cut quartz crystal materials that is little affected by temperature, so it is also not affected by temperature factor. Sensors based on the principle of SAW, can form a complete sense of passive wireless sensor system. Therefore, compared to traditional pressure sensor, the sensor designed in this paper has a high accuracy and application flexibility.