Improving the performance of null-field generation based preconditioner with approximate MLFMA technique

In this paper, we improve the performance of the efficient null-field generation based preconditioning scheme by combining with the approximate MLFMA technique. The impedance matrix generated by the null-field generation based scheme is more diagonal dominant than the conventional impedance matrix and fewer iterations will be achieved when far-field interactions are considered by AMLFMA technique. Representative numerical examples are given to illustrate the validity and efficiency of the proposed preconditioning scheme.