An accelerated DFT-MoM for the analysis of large finite periodic antenna arrays in grounded layered media

The DFT-based approximate of the impedance matrix is employed as a preconditioner in the iterative method to provide an efficient and accurate solution of integral equations for solving electromagnetic scattering and radiation problems of large finite periodic antenna arrays in grounded layered media. The DFT-based preconditioner is shown to effectively improve the convergence of the iterative solutions. The complexity of the preconditioner implementation is O(KlogK) in computational cost and O(K) in memory requirement for problem size of O(K).