Electromagnetic scattering analysis using a combined magnetic field integral equation for small objects with flat surfaces

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 decreases the accuracy of MFIE for objects with flat surfaces. To solve this problem, the normal magnetic field integral equation resulting from the use of the normal boundary condition is considered. It is then combined with the traditionally used MFIE into a new MFIE formulation, named the combined magnetic field integral equation (CMFIE). Through the use of an appropriate combination parameter, the omitted contribution of the Green's function to the scattered magnetic fields in the traditionally used MFIE can be recovered in this new CMFIE. Numerical results validate the analysis and show that the proposed MFIE formulation is much more accurate than the traditional one for small objects with flat surfaces. (C) 2015 Optical Society of America