Transverse energy confinement and resonance suppression in SAW resonators using low-cut lithium tantalate

Abstract

This paper discusses the applicability of double busbar design to surface acoustic wave (SAW) devices employing low-cut lithium tantalate (LT) with multi-layered structure. This design offers good energy confinement, scattering loss suppression and transverse mode suppression for a wide frequency range. In addition, the effectiveness of manipulating the slowness curve shape for transverse mode suppression is demonstrated. First, three different lateral edge designs are applied to the layered SAW configuration on low-cut LT, and their performances are compared using the periodic 3-dimensional finite-element method powered by the hierarchical cascading technique. Then, the discussion is extended to influence of the SAW slowness shape to the transverse mode suppression.

Application of an overlay for spurious suppression of multi-layered surface acoustic wave resonators with double busbar configuration

“…[12][13][14][15][16] The authors proposed the double busbar configuration for suppression of lateral energy leakage and demonstrated further Q enhancement. [17][18][19] In many cases, the Q enhancement makes not only the main resonance but also the spurious ones prominent. Generally, transverse mode resonances are the most troublesome.…”