A subdomain adaptive integral method for arbitrarily shaped objects

A novel subdomain adaptive integral method (SAIM) is presented for fast analysis of electromagnetic radiation and scattering from three dimensional objects of arbitrary shape. In conventional AIM, a uniform Cartesian grid is built up to entirely enclose the object, and auxiliary point sources are used to efficiently calculate far-zone interactions. However, adopting one Cartesian grid will actually cause large amount of auxiliary point sources redundant for the far-zone interaction calculation. To reduce the excess of those redundant auxiliary point sources, in the proposed SAIM, the whole domain is divided into several subdomains and then each subdomain is properly enclosed in its smaller Cartesian grid. Furthermore, the current continuity boundary condition between adjacent subdomains is employed to ensure the accuracy. Compared with the conventional AIM, the proposed SAIM technique can significantly reduce the number of auxiliary point sources and improve the convergence of iterative process. Numerical examples show the accuracy and efficiency of the proposed technique.