Thin plate model for transverse mode analysis of surface acoustic wave devices

Abstract

In this paper, we propose a physical model for the analysis of transverse modes in surface acoustic wave (SAW) devices. It is mostly equivalent to the scalar potential (SP) theory, but sufficiently flexible to include various effects such as anisotropy, coupling between multiple modes, etc. First, fundamentals of the proposed model are established and procedures for determining the model parameters are given in detailed. Then the model is implemented in the partial differential equation mode of the commercial finite element analysis software COMSOL. The analysis is carried out for an infinitely long interdigital transducer on the 128°YX-LiNbO3 substrate. As a demonstration, it is shown how the energy leakage changes with the frequency and the device design.

Enhanced Sensitive Surface Acoustic Wave Device Designed for Nitric Oxide Gas Detection

“…For example, the model using the COM theory requires less time for executing a program but requires some effort to derive equations and parameters for different IDT structures. (29) By contrast, the EC is very flexible and thus easily fits various IDT structures; nevertheless, the calculation requires a higher number of iterations to form electrodes in an organized manner, thus requiring a long execution time. (30) In this study, the COM and EC models were combined to employ their different advantages by developing a new modified EC model that converted COM parameters into EC parameters with a metallization ratio of 0.5.…”

Field analyses of thickness shear bulk acoustic resonators with different electrode edge ratio using full three dimensional finite element method simulation

“…1) Suppression of transverse mode responses without quality factor Q deterioration is always challenging for realizing high performance acoustic resonators. [2][3][4][5] A famous strategy is the piston mode operation proposed by Kaitila et al, 6) whereas its operation frequency range is limited due to the necessity of the frequency-dependent phase adjusting mechanism. Another well-known technique is apodization, 7,8) while it causes Q deterioration due to wave scattering.…”

Broadband piston mode operation of solidly mounted resonator employing A1 Lamb mode on lithium niobate

“…11,12,17) Suppression of transverse mode resonances is always one of the most important research targets for any kind of acoustic wave resonators. [18][19][20][21] For this purpose, various techniques were proposed; apodization of an interdigital transducer (IDT), 22) weighted dummy electrodes, 23) selective removal 24) of the waveguide structure, and piston mode (PM) design. 21,[25][26][27] Recently, the authors pointed out that when the rotated Y-cut LN is employed for the A 1 Lamb mode resonator, transverse mode resonances and lateral energy leakage can be suppressed well for a wide frequency range by placing release windows (etched holes) near the IDT electrode tips.…”