Fast computation of 3D inhomogeneous scattered field using a discrete BCG-FFT algorithm

A discrete formulation is presented for solving the shortcomings of existing methods used in the computation of scattered fields from arbitrary scatterers in a 3D space. The scattered fields from dielectric scatterers with arbitrary geometry are modeled using integral equation with equivalent sources. The inhomogeneity of the parameter of the scatterer is approximated by a set of 3D simple functions. The total field is represented by a set of local basis functions. A Galerkin testing formulation is applied and no approximation is made to the differential operators involved in the integral equation except for the projection of the unknown field and the operators onto the subspace spanned by the basis functions. To illustrate the use of this method, the total electric field and the bistatic radar cross section of inhomogeneous spherical objects are computed.