A novel design method for SAW temperature sensor with monotonic and linear frequency-temperature behavior in wide temperature range

Abstract In this work, a novel method was proposed to achieve linear temperature dependent frequency in SAW temperature sensors. The designed SAW temperature sensor can operate in a wide temperature range without the limitation originated from the large second-order frequency-temperature coefficient of traditional SAW resonators. An SAW temperature sensor which consists of two SAW resonators was designed with the proposed method. The frequency characteristics of the SAW resonators were measured from room temperature up to 600 °C. The resonance frequency shows good linearity as the function of the temperature. This novel design method can be widely applied in the SAW temperature sensors based on the piezoelectric substrates with large second-order frequency-temperature coefficient.