On interior resonance problem of integral equations for modeling electromagnetic scattering from cavities

In this paper, we first develop the boundary integral equations for electromagnetic cavity problem using a symmetric equivalent currents model with images. To check the well-posedness of the proposed integral equations, the condition numbers of the resultant matrices from the GNF formulation and the proposed integral equations are analyzed for different frequencies and depth of the cavity, respectively. The numerical analysis on the condition numbers obtained also show that the integral equations proposed in this paper are immune to the problem of the interior resonance for 3D cavity problem