The application of continuity condition in volume-surface integral equation combined with the multilevel fast multipole algorithm

The application of the continuity condition of the electric flux field at the conductor-dielectric boundaries is discussed. For the conductor-dielectric composite structures involving closed conducting surfaces, a new form of volume-surface integral equation, combined field integral equation-volume integral equation enforced the continuity condition is proposed. The matrix equation generated by the proposed method can be iteratively solved in a straightforward manner and can benefit from the application of the multilevel fast multipole algorithm. Numerical results show that the explicit enforcement of the continuity condition can reduce not only the peak memory requirement and the CPU time of a single iteration in the solution, but also the total iterative steps to reach convergence.