Efficient FDTD/matrix-pencil method for the full-wave scattering parameter analysis of waveguiding structures

A combined finite-difference time-domain/matrix-pencil method is presented for the efficient and rigorous calculation of the full-wave modal S-parameters of waveguide components including structures of more general shape or high complexity. The application of the S-parameter definition for unmatched ports requires merely standard Mur's absorbing boundaries for reliable results, and a nonorthogonal or contour path mesh formulation allows the convenient inclusion of curved boundaries. The efficiency of the method is demonstrated for the analysis of waveguide and monolithic microwave/millimeter wave integrated circuit (MMIC) components of practical importance, such as the twisted waveguide, the twisted waveguide bend, the post compensated magic T, the waffle-iron filter, and the MMIC spiral inductor including an air bridge. The method is verified by excellent agreement with measurements, with finite element method (FEM) or moment method results.