A magnetic field integral equation based iterative solver for scattered field prediction

An iterative solution scheme based on the magnetic field integral equation (MFIE) to compute electromagnetic scattering for arbitrary, perfect electrically conducting (PEC) objects is topic of this contribution. The method uses simple and efficient approaches for the computation of surface current interactions which are typically found in the well-known iterative physical optics (IPO) technique. However, the proposed method is not asymptotic, since no physical optics (PO) concepts are utilized. Furthermore, a least squares correction method is introduced, which is applied not on the complete current vector, but on individual groups of currents. This helps to quickly reduce the residual error and to improve convergence. The result is a simple method which is capable to improve the simulation results obtained by pure asymptotic methods such as PO or shooting and bouncing rays (SBR). The method can be regarded as a simplified iterative method of moments (MoM) technique. Numerical examples show that the proposed approach is advantageous e.g., in problem cases where the neglect of diffraction effects or currents in shadow regions would cause large errors. It also provides an improved prediction of the peak scattering contributions.