A Two-dimensional analysis of surface acoustic waves in finite plates with eigensolutions

Abstract

It is generally known that surface acoustic waves, or Rayleigh waves, have different mode shapes in infinite plates. To be precise, there are both exponentially decaying and growing components in plates appearing in pairs, representing symmetric and anti-symmetric modes in a plate. As the plate thickness increases, the combined modes will approach to the Rayleigh mode in a semi-infinite solid, exhibiting surface acoustic wave deformation and velocity. As a result, for plates with finite thickness, we need to consider the effect of two modes in the analysis. ... In this study, the two-dimensional theory for surface acoustic waves in finite plates is extended to include exponentially growing modes in the expansion function, creating a twodimensional equation system for plates with finite thickness. Since additional expansion functions are also exponential, the two-dimensional equations keep the same appearance, implying the same evaluation and solution procedure. These results are important in the improvement of two-dimensional analysis of surface acoustic waves in finite solids, which are the essential problem in surface acoustic wave resonator analysis and design