Approximate analysis of surface acoustic wave Delta nu / nu waveguide with general anisotropy

The authors present an approximate analysis of guided waves in a SAW (surface acoustic wave) Delta nu / nu waveguide with general anisotropy. The proposed analysis is performed under the assumption that fields in the guiding and surrounding regions can be expressed in terms of a linear combination of variable-crested surface wave solutions for the unbounded metallized or free surface having a common wave number in the propagation direction. Specifically, the expression is developed for an eigenvalue equation of the guided wave solution based on the scattering analysis of the variable-crested waves at the metal/free surfaces. Numerical results on dispersion curves and field distributions of the guided on various anisotropic substrates are shown. A number of peculiar properties due to the anisotropy are demonstrated. The results of the accurate analysis based on the integral equation method are also shown, to verify the effectiveness of the proposed analysis.