Performances of projection iterative method on electromagnetic scattering by spheres

In order to solve large electromagnetic scattering problems with less computer memory and less execution time, iterative based numerical methods have been sought for the matrix equation obtained by the method of moments (MoM). A projection iterative method (PIM) is a convergence guaranteed method which has not been widely applied in electromagnetics. In this method, the solution is improved by means of an orthographic projection procedure. The decomposition technique is that the unknowns are not decomposed in space. A series of sub-equations defined on subdomains are solved in each iterative step. The computer memory is much less than that of the direct method for the original equation when the sub-equation size is small. Therefore it is potentially applicable to large electromagnetic problems.