Theorectical Optimazation of Surface Acoustic Waves Resonator based on 37°Y-47°X LINBO3/SIO2/SIC Multilayered Structure

Longitudinal SAW mode (L-SAW) has a higher phase velocity and thus brings about a higher working frequency. In this paper, a 37°Y-47°X LiNbO
3
/SiO
2
/SiC multilayer structure is proposed to excite L-SAW at high velocity and high electromechanical coupling coefficient (K
²
) to meet the frequency requirement of 5G. Moreover, by changing the thicknesses of SiO
2
and LiNbO
3
in the structure, theoretical optimization is performed using finite element method (FEM) and the results show that the optimal thickness of LiNbO
3
is 0.08λ, that of SiO
2
is 0.2λ, and that of the electrode is 0.056λ. For the optimized structural parameters, the L-SAW has a K
²
of 10.95%, and the corresponding phase velocity is 5800.43 m/s, TCF is -0.1ppm/°C.