HYBRID FINITE-DIFFERENCE TIME-DOMAIN MODELING OF CURVED SURFACES USING TETRAHEDRAL EDGE ELEMENTS

A hybrid finite-difference time-domain (FDTD) method is proposed for s olving transient electromagnetic problems associated with structures o f curved surfaces. The method employs the conventional FDTD method for most of the regular region but introduces the tetrahedral edge-based finite-element scheme to model the region near the curved surfaces. Wi thout any interpolation for the fields on the curved surface, nor any additional stability constraint due to the finer division near the cur ved surfaces, the novel finite-element scheme is found to have second- order accuracy, unconditional stability, programming ease, and computa tional efficiency. The hybrid method is applied to solve the electroma gnetic scattering of three-dimensional (3-D) arbitrarily shaped dielec tric objects to demonstrate its superior performance.