The inclusion of fringing capacitance and inductance in FDTD for the robust accurate treatment of material discontinuities

The analysis of structures, which contain sharp material discontinuities us ing the finite-difference time-domain method (but without resorting to a ve ry fine mesh) although much researched, has not yet been definitively solve d. In this paper, the fringing fields associated with the discontinuities a re dealt with by adjusting the permittivity and permeability assigned to th e field nodes that are immediately adjacent to the discontinuities. This me thod is shown to be effective for a variety of structures and to be without the problems of violating energy or divergence conservation.