Design of RF temperature measurement system of delay linear SAW temperature sensor based on FPGA

Abstract

The delay line SAW (Surface Acoustic Wave) temperature sensor is a kind of wireless passive temperature sensor. The sensor uses the RF antenna to receive the RF signal to excite the internal IDT, thus forming SAW signal on the surface of piezoelectric substrate material. The three reflectors inside the sensor successively reflect the SAW signal to the IDT; finally, the IDT transmits the reflected signal back through the RF antenna. According to the characteristics of SAW temperature sensor, a set of temperature measurement system is made. The hardware and software of the temperature measurement system are designed, so that the whole temperature measurement system can measure the temperature between $25^{\circ}\mathrm{C}$ and $130^{\circ}\mathrm{C}$, and the temperature measurement error is required to be less than $1^{\circ}\mathrm{C}$.