Analysis of the electromagnetic scattering from flat plates by using different sinc-type basis fuctions in method of moments

Abstract

Electromagnetic scattering from three dimensional arbitrary flat surfaces illuminated by a plane wave is investigated by using sinc-type basis functions in the method of moments (MoM) in this study. Sinc-sinc based Galerkin MoM formulation is obtained and its fortran program is developed firstly. The number of integrals to be computed is decreased by using analytical properties of the sinc function in the formulation. Therefore, the CPU time for obtaining the coefficient matrix is decreased appreciably. The relative error during the generation of the main matrix elements is obtained between 0.058% and 0.095% for considerably large matrices. Rooftop based MoM formulation is developed and it is coded with a similar approach used in sinc based program. The accuracy and CPU time of the sinc based bistatic scattering results are compared with those of rooftop. The MoM formulation of the sinc-pulse (sinctop) basis functions with non-Galerkin case is developed to reduce the overflow problem at the edges. Induced surface currents and far-field results of the sinc-sinc and sinc-pulse based formulations are compared with those of the rooftop basis functions and with the ones obtained from SuperNEC. Both sinc-sinc and sinc-pulse based simulation results are in good agreement with the results of rooftop based and SuperNEC simulation results. The main purpose in this study is to obtain accurate bistatic scattering results by using different sinc-type basis functions in MoM procedure while filling the main matrix in less CPU time when compared with the well-known methods.