Double Busbar Structure for Transverse Energy Leakage and Resonance Suppression in Surface Acoustic Wave Resonators Using 42°YX-Lithium Tantalate Thin Plate

This article describes a new transverse edge structure with double busbar for surface acoustic wave (SAW) devices employing a 42°YX-lithium tantalate thin plate such as incredible high-performance (I.H.P.) SAW. This design offers good energy confinement and scattering loss suppression for a wide frequency range. First, preexisting transverse edge designs are reviewed, and their difficulties are pointed out using the dispersion relation for lateral SAW propagation. Then, numerical simulations are performed using the periodic 3-D finite-element method (FEM) powered by the hierarchical cascading technique, and effectiveness of the proposed structure is revealed. In addition, we also provide a possible solution to expand the frequency range giving well energy confinement and demonstrate effectiveness of manipulating the SAW slowness curve shape for transverse mode suppression.