Using an accurate singularity extraction technique to the MFIE for the scattering analysis of small objects

The method of moments (MoM) solution on the magnetic field integral equation (MFIE) for electromagnetic scattering problems of conducting objects with Rao–Wilton–Glisson (RWG) basis functions requires the evaluation of almost singular double surface integrals over triangular subdomains. Calculating these integrals accurately is essential for the successful solution of the MFIE by MoM especially for small sharp-edged conducting objects. This paper studies the singularity of the MFIE and uses an accurate singularity extraction technique to avoid logarithmic singularity of the integration on the testing triangles for the MFIE. Based on the numerical examples of several small sharp-edged conducting objects, it is demonstrated that the accuracy of the MFIE is improved greatly with the use of the new singularity extraction technique.