Wave energy localization near the rough surfaces of piezoelectric waveguide. Near-surface inhomogeneities as a resonator or filter

Abstract

Abstract Propagation of high-frequency electro-elastic normal wave signal in a composite waveguide is investigated. The roughnesses on a two surfaces of the piezoelectric waveguide are filled with an ideal conductor and ideal dielectric respectively. The both of the influence of surface roughness and the influence non-homogeneity of materials near the surfaces on the process of high frequency electro-elastic normal wave signal propagation, is discussed. The behaviors the frequency characteristics of wave in the composite waveguide at the propagation of normal wave signals numerically are investigated. The problem by the method of virtual cross sections and input of Magneto Elastic Layered System (MELS) hypotheses is solved. It is shown that in a case of not filled roughness of the piezoelectric layer surfaces, only two short wave modes are arise. The filling of the surface roughness with a dielectric or a conductor respectively, leads to the appearance of up to four such wave modes, depending at the wave signal length. The dispersion dependencies for all possible characteristic modes of shear electroelastic waves are given. It is shown that in a case of the propagation of slow waves, on certain wave lengths the silence frequency zones are arise.