A Nonconformal Surface Integral Equation for Electromagnetic Scattering by Multiscale Conducting Objects

We present a nonconformal surface integral equation method for the analysis of time-harmonic electromagnetic scattering by multiscale perfect electrically conducting (PEC) objects. To alleviate the burden of geometrical processing, a mixed triangle/quadrilateral mesh with arbitrary nonconformity is adopted in this method. A vectorial piecewise constant basis function is defined over the unstructured mesh as the trial and test functions. The recently developed reverse operation self-consistent evaluation approach is employed to evaluate the hypersingular integrals. Due to the utilization of this locally defined basis function, the function space is enlarged from the commonly used div-conforming space to the square-integrable counterpart. Therefore, it will be possible to apply different polygonal elements or basis functions with different orders according to the local characteristics of the geometry. Several numerical results are presented to validate the accuracy and demonstrate the versatility of the proposed method for modeling multiscale and electrically large PEC objects.