A hybrid implementation of the FDTD and moment methods

The finite-difference time domain (FDTD) method is a commonly used electromagnetic simulation method. However, in the analysis of electrically large structures with curved boundaries, the FDTD method suffers from cumulative errors introduced by inadequate resolution of curvature (stair-casing errors), reflection from absorbing boundaries, numerical dispersion, etc. On the other hand, integral equation based methods such as the method of moments (MoM) have available a wide variety of shape functions and grids for accurate resolution of the field on curved boundaries. We propose to hybridize the FDTD method and the MoM such that FDTD can be implemented on a relatively crude mesh, and the resulting "crude" solution employed as an initial guess to the solution of the MoM matrix equations using the conjugate gradient (CG) method.