SAW diffraction using the thin-element decomposition method

摘要

We adapt the angular spectrum of plane waves (ASPW) decompositionnto numerical simulations of the diffraction of surface-acoustic wavesn(SAWs) on anisotropic model substrate, such as YZ lithium niobate. Wenutilize the thin-element decomposition (TED) method, appropriatelynmodified for an anisotropic substrate; we also introduce a noveln“average-wavenumber” variation of this scheme; these arennumerically found to be mutually consistent. We apply the TED method tonsimulate wave propagation both in infinite periodic structures ofnmetallized gratings and also in finite gratings. We demonstrate that thenASPW provides a convenient and numerically fast tool for precisendiffraction calculations in practical SAW devices which also displaynstructural variations in the lateral direction, perpendicular to thenprincipal direction of wave propagation. Additionally, we compare thenpresent TED method to waveguide theory in an analysis of the role of SAWnreflections from the electrodes