Abstract

In this paper the theoretical foundation of the fast multipole method (FMM) applied to electromagnetic scattering problems is briefly presented, the truncation of the GREEN's function expansion is revisited, and the well established truncation criteria, in terms of the relative accuracy of the solutions of the electric field integral equation, is revised from a numerical experiment. From this numerical procedure an interesting result for the number L of poles is reported. In FMM L is the number of terms in the GREEN's function expansion and it determines the precision of such an expansion. In our experiment a lesser value of L is obtained compared to previous studies.