Comprehensive Solution to Scattering by Bianisotropic Objects of Arbitrary Shape

This paper presents a method of moments (MoM) solution for the problems of electromagnetic scattering by inhomogeneous three- dimensional bianisotropic scatterers of any shape. The electromagnetic response of bianisotropy has been described by the constitutive relations of the most general form composed of four 3 X 3 matrices or tensors. The volume equivalence principle is used to obtain a set of mixed potential formulations for a proper description of the original scattering problem. Here, the total fields are separated into the incident fields and the scattered fields. The scattered fields are related to the electric and magnetic potentials which are excited by electric and magnetic bound charges and polarization currents. The body of the scatterer is meshed through the use of tetrahedral cells with face-based functions used to expand unknown quantities. At last, the Galerkin test method is applied to create a method of moments (MoM) matrix from which the numerical solution is obtained. Implemented in a MATLAB program, the numerical formulation is evaluated and verified for various types of scatterers. The results are compared with those of previous work, and a good agreement is observed. Finally, a scattering from a two-layered dispersive chiroferrite sphere is presented as the most general example

A Two-Dimensional Single-Field FDTD Formulation for Oblique Incident Electromagnetic Simulations

Abstract A set of general purpose two-dimensional single-field finite-difference time-domain updating equations for solving oblique incidence electromagnetic problems is derived. The traditional FDTD updating equations are based on Maxwell's curl equations whereas the single-field FDTD updating equations are based on the vector wave equation. Performance analyses of the single-field formulation in terms of CPU time and memory requirement are presented along with numerical validation. It was observed that the single-field method is more efficient than the traditional FDTD formulation in terms of speed and memory requirements for oblique incident problems

Time-domain iterative multiregion technique for 3-D scattering and radiation problems

WOS: 000375596100024Integration of the finite-difference time-domain (FDTD) method into the iterative multiregion (IMR) technique, an iterative approach used to solve large-scale electromagnetic scattering and radiation problems, is presented in this paper. The idea of the IMR technique is to divide a large problem domain into smaller subregions, solve each subregion separately, and combine the solutions of subregions after introducing the effect of interaction to obtain solutions at multiple frequencies for the large domain. Solutions of the subregions using frequency domain solvers has been the preferred approach as such; solutions using time domain solvers require computationally expensive bookkeeping of time signals. In this paper, we present an algorithm that makes it feasible to use the FDTD method, a time domain numerical technique, in the IMR technique to obtain solutions at a prespecified number of frequencies in a single simulation. A hybrid method integrated into the IMR technique is also presented in this paper. This hybrid method combines the desirable features of the FDTD method and the method of moments (MoM) to solve radiation problems more efficiently. As a result, a considerable reduction in memory storage requirements and computation time is achieved