Accurate solution of volume integral equations for electromagnetic scattering by conductive objects

The electromagnetic (EM) problems with conductive objects can be solved by surface integral equations (SIEs) with the method of moments (MoM) discretization in the integral equation approach. However, the solutions may not be valid for a wide range of frequency and conductivity. In this work, we use the volume integral equations (VIEs) to formulate the problem and propose a point-matching scheme to solve it. The VIEs are usually well-conditioned because they are the second-kind of integral equation. The point-matching scheme can select current densities as unknowns so that the integral kernels are free of material parameters and the solutions can bear a significant change of frequency and conductivity. A numerical example for EM scattering by a conductive sphere with different parameters is presented to demonstrate the approach.