Characteristic Mode Analysis for Thin Dielectric Sheets with Alternative Surface Integral Equation

When the dielectric sheet is electrically thin in the normal direction, the conventional volume integral equation (VIE) can be approximately simplified to the surface one. On this basis, a novel surface integral equation-based formulation is presented for analyzing characteristic mode (CM) of thin dielectric sheets. The resultant CMs are expressed with tangential and normal components of electric volume currents, which are more intuitive than the conventional VIE-based one. Due to the application of volume equivalence principle, the proposed formulation is immune to non-physical modes. The CMs of typical thin dielectric bodies, including the dielectric substrate and radome, are analyzed to show that the proposed formulation is computationally efficient with encouraging accuracy.