Spurious Mitigation of Layered Surface Acoustic Wave Resonators With Double-Busbar Configuration Using 42°YX-Lithium Tantalate Thin Plate

This article investigates a spurious resonance appearing near the antiresonance when the double-busbar configuration is applied to layered surface acoustic wave (SAW) resonators using 42°YX-LiTaO
₃
thin plates, and possible mitigation methods are studied both theoretically and experimentally. First, the origin of the spurious resonance is revealed, and the influence of structural parameters is studied using the periodic 3-D finite-element method (FEM) powered by the hierarchical cascading technique (HCT). Then, possible methods are discussed for spurious mitigation. Finally, experimental data are provided for validation of the present analysis.