Investigation of the projection iterative method in solving the MoM matrixequations in electromagnetic scattering

The projection iterative method (PIM) is convergence guaranteed when applie d to solve the MoM equations with nonsingular matrices. Its decomposition p rocedure divides the matrix into some small subregions to avoid large matri x inversions. It is found that the convergent rate can be accelerated by in troducing the relaxation factor to the PIM formulation. Three 3D examples a re investigated to show the performance and validation of the PIM on electr omagnetic scattering problems. A 2D infinite circular cylinder with TE fiel d illumination is also studied to show the convergence of the method. The r elationship of various PIM related parameters, such as the normalised resid ual norm, the number of iterations, the number of divided subregions, and t he relaxation factor, is studied and presented. It is concluded that the op eration count of the accelerated PIM is usually comparable to the direct me thod and the PIM can predict the RCS faster than the direct method with a r easonable accuracy.