Unconditionally stable FETD method using Laguerre polynomials for eigenvalue problems

This paper presents an unconditionally stable finite-element time-domain (FETD) scheme to solve time-dependent vector wave equations for eigenvalue problems. With the weighted Laguerre polynomials as basis functions and Galerkin´s testing procedure, the temporal derivative in the vector wave equation can be handled analytically. Combined with the discrete Fourier transform (DFT), the Laguerre-FETD method is applied to the solution of eigenvalue problems. The numerical example of a circle dielectric-loaded waveguide shows its advantages of accuracy and efficiency.