Near-Zero TCF SH0 Plate Acoustic Wave Resonators Using 36°YX-LiTaO3/SiO2 Film

This work proposes a zero-th shear horizontal (SH 0 ) plate acoustic wave (PAW) resonator based on 36° Y-cut lithium tantalate (LT) / silicon dioxide (SiO 2 ) thin film. By using multi-physics finite-element-analysis (FEA) simulations, the rotation angle of LT and the layer thicknesses are optimized for obtaining large effective electromechanical coupling coefficient $\left( {{k^2}_{{\text{eff}}}} \right)$ and low temperature coefficient of frequency (TCF). The fabricated resonators yield a ${k^2}_{{\text{eff}}}$ of 11.8% and a Bode-Q max of 1795. Moreover, the measured temperature coefficient of frequency at anti-resonant frequency (TCF fp ) is -4.9 ppm/°C, indicating that a near-zero TCF is realized in this study. The demonstrated resonators are promising for low loss and temperature-stable acoustic devices in wireless communication system.