COUPLED BACKWARD WAVES IN CERTAIN PLANAR DOUBLY PERIODIC SYSTEM

摘要

Surface acoustic wave is considered to propagate in a piezoelectric body which surface is perturbed by two periodic gratings of different period. One grating, metal strips, interacts with the wave by electric means only. It provides coupling of the forward and backward surface waves. The other grating, shallow grooves, provides coupling of these waves to another surface mode supported by the considered piezoelectric body. Dispersive relations are discussed within the frame of the perturbation theory verified by certain simple experiments for periodic structures.