Abstract

This article provides insight into the modeling of waveguides using the discontinuous Galerkin time-domain (DGTD) method. The spatial domain decomposition in the DGTD method is controlled by changing the resolution of the finite elements (FEs) which in turn have effect on the stable time marching step. Different resolutions of FEs support different resonant modes. This paper investigates the effects of the resolution of FEs and the effect of Final Timeon appearance of low and high–frequency resonant modes in the waveguides. The experimentation is performed by considering the both transverse magnetic (TM) and transverse electric (TE) polarizations. The unstructured triangular mesh type is considered for the analysis. Integration in the temporal domain is achieved by using five-stage 4^th order low-storage Runge-Kutta (LSERK) method and the stability of the numerical method is ensured by stable time marching step which is calculated by using Courant-Friedrichs-Levy (CFL)condition. The operation is performed on WR90 waveguide and the analytical and numeric values for various resonant modes are compared to validate the study.

Keywords

DGTD, Modeling of waveguide, CFL, Effect of resolution of finite elements, Effect of final time, Resonant modes of waveguide, WR90 waveguide, Transverse magnetic, Perfect electric conductor, FFT, Radar, Analytical methods, Final time, Resonant modes, Numerical fluxes, Upwind, Numerical methods