Band gaps and the electromechanical coupling coefficient of a surface acoustic wave in a two-dimensional piezoelectric phononic crystal

Abstract

In this paper we analyze the phononic band structure of bulk and surface waves in a two-dimensional periodic structure consisting of an array of piezoelectric cylinders in an isotropic background material. The explicit formulations of the bulk wave and the surface wave dispersion relations in such a structure are derived based on the plane wave expansion method. The band gaps and the electromechanical coupling coefficients for surface acoustic waves propagating in such a structure are calculated. The influences of material and geometrical anisotropy as well as the filling fraction on the electromechanical coupling coefficients are discussed, and some silent features are drawn. The results of this research may serve as an important reference for studying surface acoustic wave devices consisting of phononic structures.