Hierarchical Cascading in FEM Simulations of SAW Devices

Application of the finite element method (FEM) for the simulation of SAW devices has traditionally been constrained by the large number of degrees-of-freedom required, resulting in large memory usage and long computation times, and limiting the accuracy of the simulation. In this paper we review the recently introduced hierarchical cascading method, which offers drastically reduced memory consumption and simulation times in 2D simulations. In 3D, the advantages of hierarchical cascading are diminished due to the high number of cross-sectional degrees-of-freedom. As a partial solution to this problem, an iterative hierarchical cascading method is proposed, with reduced number of effective degrees-of-freedom. Examples of simulations of finite devices in 2D and of a periodic array in 3D are provided.