Efficient Algorithm for Scattering Simulation of Multiple IBC Targets Based on Self-Dual Integral Equation With MLFMA–FAFFA

An efficient algorithm is presented for accurately calculating electromagnetic (EM) scattering from multiple impedance boundary condition (IBC) targets, and individual unit in the group is dealt with separately based on the combined self-dual IE (C-SDIE). To rapidly analyze multiple targets with IBC, the translation matrix concept of the multilevel fast multipole algorithm (MLFMA) is applied to calculate the EM coupling between targets. One advantage of this approach is its capability of reusing data structures for identical targets. In addition, it facilitates generating an initial solution (IS) that is close to the exact solution for group targets based on a single target. Moreover, the fast far-field approximation (FAFFA) is used to further improve computational efficiency. Numerical results demonstrate that the proposed method has promising numerical performance in terms of accuracy, efficiency, and capability.