Electromagnetic scattering analysis using the combination of MFIE and normal EFIE

For electromagnetic analysis using Method of Moments (MoM), three-dimensional (3-D) arbitrary conducting surfaces are often discretized in RWG basis functions. The contribution of the Green's function to the scattered magnetic field is not well expressed in the traditionally used magnetic field integral equation (MFIE) when the source and field points lie on the same plane. This leads to the inaccuracy of MFIE for objects with flat surfaces. To solve this problem, some researchers proposed a normal magnetic field equation using the magnetic normal boundary condition. It is then combined with the traditional MFIE to form a new MFIE formulation, named the combined magnetic field integral equation (CMFIE). Through the use of an appropriate combination parameter, the lost contribution of the Green's function to the scattered magnetic fields in the MFIE can be recovered in this new CMFIE and can mitigate the discrepancy in RCS.