A SAIM-FAFFA Method for Efficient Computation of Electromagnetic Scattering Problems

A novel method is proposed through an effective combination of the subdomain adaptive integral method (SAIM) with the fast far-field approximation (FAFFA) for efficient computation of electromagnetic scattering problems. In the SAIM technique, the whole perfectly electrically conducting structure is decomposed into subdomains and each subdomain is properly handled by the AIM with its local Cartesian grid individually. A current continuity boundary condition is introduced on the interface between contiguous subdomains to guarantee the accuracy. Moreover, the FAFFA technique is utilized to speed up the process of updating the modified excitation vectors. Numerical results show that the present hybrid method can not only significantly decrease the number of auxiliary grid points and the memory requirement of Green's function matrix, but also improve the convergence of the iterative process compared to the conventional AIM.