Quantum Leap in Simulation Technologies for Radio Frequency Surface and Bulk Acoustic Wave Devices Gifted by Hierarchical Cascading Technique

This paper describes how the hierarchical cascading technique (HCT) expanded capabilities of FEM-based numerical simulation in radio frequency surface and bulk acoustic wave (SAW/BAW) devices. The HCT was originally proposed for speed up and size-reduction of two-dimensional FEM simulation of SAW resonators. The authors' group applied 2D and 3D HCT to attack various problems on SAW/BAW excitation and scattering including those believed to be impossible. The traveling wave excitation source proposed by the author's group fits well with HCT and can be adapted efficiently in these analyses. First basics of HCT and its extensions are explained, and then these techniques are applied to various practical problems as demonstration.