A High Sensitivity Temperature Sensor Using High-Q NS-SAW Resonator

In this paper, a temperature sensor based on non-leaky stack surface acoustic wave (NS-SAW) resonator is proposed. Specifically, LiNbO3 (LN)/SiO2/Si multilayered structure is adopted to reduce the acoustic energy leakage of SAW resonator, and a high quality-factor (Q) is reached for improving the sensitivity of SAW type temperature sensor. To systematically explore the temperature-dependent frequency response of the proposed design, simulation and experimental investigations were performed, revealing that LN-based NS-SAW resonator owns a high Q compared with other sensors and resonators. Meanwhile, the acceptable temperature coefficient of frequency (TCF) and great linearity of our device offer a big advantage for sensing applications. Accordingly, a high sensitivity temperature sensor with −26.01 ppm/°C TCF and 862 Bode-Qmax is obtained simultaneously.