Low frequency stability of the mixed discretization of the MFIE

Recently, a novel discretization for the magnetic field integral equation (MFIE) was presented. This discretization involves both Rao-Wilton-Glisson (RWG) basis functions and Buffa-Christiansen (BC) basis functions and is dubbed `mixed´. The scheme conforms to the functional spaces most natural to electromagnetics and thus can be expected to yield more accurate results. In this contribution, this intuition is corroborated by an analysis of the low frequency behavior of the classical and mixed discretizations of the MFIE. It is proved that the mixed discretization of the MFIE yields accurate results at very low frequencies whereas the classical discretization breaks down, as was already discussed extensively in literature.