Accurate and efficient simulation of scattering by large objects with anisotropic impedance surfaces

A surface integral equation (SIE) is presented for analyzing electromagnetic scattering from complex targets with anisotropic impedance surfaces. By employing both surface electric and magnetic currents as unknowns and weakly enforcing the anisotropic impedance boundary condition (IBC), the derived SIE exhibits good spectral property. The parallelized multilevel fast multipole algorithm (MLFMA) and sparse approximate inverse (SAI) preconditioner are developed to enable large-scale problem simulations and improve iterative convergence, respectively. Two numerical examples are presented to verify the algorithm and demonstrate its scalability and capability in simulating large complex objects with anisotropic impedance surfaces.