Efficient finite-difference time-domain computation of resonant frequencies of rectangular Lame mode resonators via a combination of the symmetry boundary conditions and the Pade approximation

Resonant frequency analysis of the fundamental and higher-order modes of Lamé mode resonators on a lossless isotropic solid is carried out by the finite-difference time-domain (FD-TD) method with the staggered grid with collocated grid points of velocities (SGCV). The symmetry boundary condition is implemented to reduce the size of the computational domain for the FD-TD method with the SGCV. One spectrum estimation technique based on the Padé approximation is employed to effectively extract the resonant frequencies from a spectrum transformed from the time series data calculated by the FD-TD method. Numerical results show the validity and efficiency of these techniques