A two parameter coupling-of-modes model for shear horizontal type SAW propagation in periodic gratings

Abstract

A closed form dispersion relation for shear surface acoustic waves (BGW, STW, leaky waves) propagating in periodic structures in the frequency range corresponding to the Bragg stopband is found. The consideration includes the changes in spatial structure of the waves mutually reflecting on the grating as well as bulk wave scattering. A comparison with numerically obtained dispersion curves for leaky waves on 36-LiTaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and with experimental data on STW in quartz shows good agreement