High Q SAW Resonators Based on Optimized Multilayer Substrate

Surface acoustic wave (SAW) devices based on multilayer substrate have extremely high-quality factors (Q), small temperature coefficient of frequency (TCF), and high stability, which give excellent solution for higher performance filters arise from the rapid development of radio frequency (RF) industry. In this paper, SAW resonators based on 36°YX-LiTaO3(LT)/SiO2/4H-SiC multilayer substrate are simulated and fabricated. The thicknesses of 36°YX-LT and SiO2 are carefully selected for better performance. The power flow angle (PFA) is calculated from dispersion and slowness curves for suppressing the transverse modes. Consistent with the simulation results, a spurious free response was achieved with tilted angle of 10°, and large ${k_{{\text{eff}}}}^2$ of 12% and peak Bode-Q of 3521 are obtained, which give high figure of merit (FoM) of 423.