A Preconditioned Restarted CMRH for the PEC Target Electromagnetic Scattering Problems

A multiresolution(MR) preconditioned restarted Changing Minimal Residual method with pivoting strategy(CMRH) is proposed for Multilevel fast multipole algorithm (MLFMA) implementations. The method can efficiently reduce the iteration number required for convergence and require slightly less storage than the Generalized Minimal Residual (GMRES). The radar cross section (RCS) of a metallic sphere and a corner reflector is calculated using combined field integral equation (CFIE), Numerical results indicated that this method is very effective in electromagnetic scattering.