İki boyutlu elektromanyetik saçılma için yeni ışın tipi Green fonksiyonları ile hibrit numerik teknikler

In this study, an alternative approach is introduced to the numerical solution of two-dimension (2D) electromagnetic (EM) scattering problems by two hybrid numerical techniques combining with the method of moments (MoM). Two new hybrid techniques based on beam pattern function have been proved to solve the electric field integral equation (EFIE) by combining them with MoM in both polarizations. The first proposed technique is named MoM procedure with complex source point (CSP) type Green's function. The conversion from an isotropic line source radiation to a directive beam radiation has been demonstrated with an expression of CSP type Green's function by using the CSP technique. In this first method, the real source position vector is replaced by a complex quantity, then Green's function generates a CSP beam. In this way, the interactions between far zone elements in the impedance matrix have become negligible, except the basis functions near to the edges of the scatterer. Consequently, the overall running time has been substantially reduced. The second proposed method is named MoM Procedure with modified Green's function by using a generalized pencil of beam function (GPOF) method. In the second method, the main matrix is strongly localized, like in the first method. However, as the beam width is much narrower compared to the first method, the radiation of this Green's function produces the higher sparsity in the main matrix. In the circumstances, the memory storage and the overall running time become much smaller so that the larger sizes can be modeled with the shorter computational times.