High temperature stable acoustic surface wave substrates of SiO2/LiNbO3 structure with super high coupling

In this study, in order to improve the temperature coefficient of frequency (TCF), the propagation characteristics of SiO2/Rotated Y-cut, X-propagating LiNbO3 leaky surface acoustic wave (SAW) substrates with a large electromechanical Coupling coefficient (k(2)), zero attenuation and zero TCF are theoretically investigated. The results showed a large k(2) of more than 0.2 (zero k(2) of Rayleigh mode), zero TCF and zero propagation attenuation for leaky SAW in the case of a short boundary at a thin film thickness of H/lambda (.)=. 0.15-0.25 (H: SiO2 film thickness, lambda: SAW wavelength). The experimental results agreed with the theoretical ones.