Resonant Frequency Analysis for Rectangular Waveguide Loaded with Anisotropic Dielectric Material Using 3D-FDTD Method

This paper deals with the resonant frequency analysis based on three dimension (3D) finite-difference time-domain (FDTD) method for rectangular waveguide which is loaded with anisotropic dielectric material. The method has been implemented to analyze and solve a wide variety of electromagnetics (EM) problems. The rectangular waveguide with the cross-section of $40\mathbf{mm}\times 20\mathbf{m}$ and loaded with anisotropic dielectric material is modeled as numerical expression of magnetic and electric fields in which the interaction of fields are analyzed using 3D-FDTD method. The results of analysis in terms of EM wave and mode that appear in the waveguide are then validated theoretically. Furthermore, similar analyses using 3D-FDTD method are also applied for an hollow rectangular waveguide as well as for a rectangular waveguide which is loaded with isotropic dielectric material. The analysis results demonstrate good agreements with the theoretical predictions, although there were 0.26-2.32% discrepancies occurred in the 3D-FDTD method.