RCS convergence versus the number of unknowns and very low frequency behavior of the galerkin MFIE discretizations of sharp-edged objects with monopolar RWG and nxRWG basis functions

We have shown for an electrically small tetrahedron that the RWG monopolar discretization of the MoM-MFIE is best converging versus the number of unknowns when compared to other MoM-MFIE discretizations, such as RWG, linear-linear or nxRWG. The result of analyzing the objects with EFIE[RWG] and an extremely fine discretization is adopted as reference because of its best convergence, coinciding with EFIE[LL]. Moreover, we have shown that when decreasing the electrical dimensions of a cube, the nxRWG discretization of MoM-MFIE shows a clear inaccuracy for frequencies where the monopolar RWG set shows still no disagreement respect to EFIE[RWG]. The validity of these observations can be extended to other examples of sharp-edged objects.