In the method of moments (MoM) electric field integral equation (EFIE) analysis of slabs of metamaterials, we show that a left-preconditioning scheme by blocks gathering interactions between basis functions belonging to each basic cell of the metamaterial reaches convergence in less iterations and with less computational time than a left-preconditioner based on discarding interactions between basis functions beyond a given distance.
Ubeda Farré, E; Rius Casals, J.M; Romeu Robert, J. Preconditioning techniques in the analysis of finite metamaterial slabs. IEEE Transactions on Antennas and Propagation, 2006, vol. 54, núm.1, pàg. 265-268