Electromagnetic Interactions Analysis between Two 3-D Scatterers Using the E-PILE Method Combined with the PO Approximation

In this paper, the electromagnetic scattering from two scatterers is analyzed from a rigorous integral formulation solved by the method of moments (MoM). G. Kubické has recently developed the EPILE (Extended Propagation-Inside-Layer Expansion) method to calculate the scattering from an object above a rough surface for a two-dimensional problem. This method allows us to calculate separately and exactly the interactions between the object and the rough surface. The purpose of this paper is to extend the E-PILE method to a three-dimensional problem. Such a 3-D problem involves a large number of unknowns and can not be solved easily with a conventional method of moments by using a direct LU inversion. Thus to solve this issue, the E-PILE method is combined with the physical optics (PO) approximation to calculate the local interactions on both the object and the rough surface. By using this hybrid method, the requirements of memory and CPU time can be reduced significantly.