Optimization Design Of Saw Wireless Passive Temperature Sensor System

Surface acoustic wave (SAW) wireless passive temperature sensor hascharacteristics such as passive, long life, hostile environment durability,easy to install and low cost. It can also work in a wide range oftemperature, so it is ideal for wireless temperature measurement.In this paper, optimization design of SAW wireless passivetemperature sensor system is studied, including three main parts: SAWtemperature sensor design, reader hardware system analysis and design aswell as frequency estimation and temperature calibration.The frequency division multiple access technology is adopted formultiple sensor measurement. Optimization design is carried out on thestructure of one-port SAW resonator. The temperature-frequencycharacteristic of resonator is obtained, then detailed parameters aredetermined to meet the design requirement of temperature sensitivity.On the basis of the reader wireless measurement principle, themeasurement uncertainty of the hardware system is analyzed theoretically,which can be used as a guide to design the RF module and signalacquisition and processing module of the reader. Finally, appropriateintegrated transceiver is chosen to achieve miniaturization of the reader.In terms of the echo signal frequency estimation, windowedthree-point interpolated DFT algorithm is proposed and its frequencyestimation uncertainty is analyzed. Finally, a suitable temperaturecalibration method is designed and the temperature measurement accuracyof the sensor system is achieved to be within1℃.