Influence of coupling with shear horizontal surface acoustic wave on lateral propagation of Rayleigh surface acoustic wave on 128°YX-LiNbO₃

Abstract

In this paper, we investigate the impact of the coupling with shear horizontal (SH) surface acoustic wave (SAW) on the propagation of Rayleigh SAW in periodic grating structures on 128°YX-LiNbO3. First, the frequency dispersion behavior with longitudinal and lateral wavenumbers of Rayleigh SAW is calculated using the finite element method (FEM) software COMSOL. It is shown that the coupling causes (1) the satellite stopband and (2) variation of the anisotropy factor. It is also shown these phenomena remain even when the electromechanical coupling factor of SH SAW is zero. Then, the extended thin plate model which can take coupling between two SAWs into account, is applied to simulate the result of FEM. Good agreement between these results indicated that the mechanical coupling is responsible for these two phenomena. Finally, including electrical excitation and detection, the model is applied to the infinitely long interdigital transducer (IDT) structure and the calculated result is compared with that obtained by the three-dimensional FEM. The excellent agreement of both results confirms the effectiveness of the extended thin plate model.

Switchability of a single port SAW resonator using the electrical Bragg band gap

“…In order to analyze the potential tunability of the resonator as a function of N OC , simulations are to be carried out. As explained by Zhang et al 20 coupling between the Rayleigh and SH modes can influence the propagation of the surface wave in the mirrors. Therefore a complete simulation of the cavity with its finite acoustic aperture must be carried out.…”

High-shear-velocity Composite Acoustic Materials of AlN/Diamond for Biological MEMS Devices

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Model parameter extraction of lateral propagating surface acoustic waves with coupling on SiO2/grating/LiNbO3structure

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