Non-conformal field-only boundary integral method for modeling EM scattering problems

Recently, a novel boundary integral equation method, namely field-only boundary integral equation (FOBIE) method, has been proposed in analyzing the electromagnetic (EM) scattering from perfectly electrically conducting (PEC) and homogeneous dielectric objects in the frequency domain. The main feature of the FOBIE method is that the Cartesian components of its electric fields can be obtained directly by solving a set of singularity free boundary integral equations. This paper will give a brief review of the FOBIE method from the EM point of view first, then extend it to handle non-conformal discretization since the continuity conditions of electric fields have already been imposed by the boundary conditions and no additional conditions are needed. A block matrix solution scheme is proposed to accelerate the solution process of the discretized matrix equation, which makes the numerical framework much more efficient. The accuracy and efficiency of the proposed method are demonstrated by analyzing the EM scattering from several canonical objects with non-conformal discretization. In addition, the time domain transient EM characteristic can be obtained by using the inverse Fourier transform to reflect the physical process of the interaction between the EM fields and object conveniently in the time domain.