Fast multipole algorithm for solving volume integral equations with conductive media

We solve electromagnetic (EM) problems with conductive media by treating conductive media as penetrable media and using volume integral equations (VIEs) to exactly formulate. The VIEs are solved by a point-matching scheme which does not relies on any basis and testing functions and allows the use of nonconforming meshes. The VIEs are well-conditioned in general and the integral kernels are free of material parameters, so the scheme can endure a wide change of frequency and conductivity. For large conductive objects, we incorporate the scheme with the multilevel fast multipole algorithm (MLFMA) to accelerate the solution process and its robustness is demonstrated by typical numerical examples.