Optimum choice of currents' expansion order in MLFMM algorithm for electromagnetic scattering

The goal of this paper is to investigate how accuracy and efficiency of MLFMM of a given level depends on the order of approximation. We performed this investigation using a corner scatterer of side 20 lambda as a benchmark. We chose this model because its RCS results show several distinctive lobes in specific directions and at different levels, calculation of which is challenging even for direct MoM. Selected results are presented indicating the optimal choice of simulation parameters.