Analysis of SAW Scattering With Discontinuous Periodic Gratings Using Travelling Wave Excitation and Hierarchical Cascading Technique

This paper proposes a technique to analyze surface acoustic wave (SAW) scattering at discontinuity in grating structures using the hierarchical cascading technique. The traveling wave excitation is applied to generate a specific SAW mode. Then the displacement distribution is obtained for the passive regions. The incident, reflected, and transmitted components are selectively evaluated by the Fourier transform so as to determine the scattering coefficients at the discontinuity. Rayleigh SAWs on the SiO2/128°YX-LiNbO3structure and SH SAWs on the 42°YX-LiTaO3structure are used as examples, and the behavior of two kinds of discontinuity are analyzed, and the obtained results are compared with those obtained by the COM model.