The Simple Rigorous and Effective Treatment of Thin Wires and Slots in the FDTD Method

The necessity of using analytical additions to the basic Yee algorithm when treating wires and slots whose dimensions are much smaller than a unit cell size in the FDTD method has been long appreciated. Although such additions exist, they are somewhat complex and, surprisingly, recent published analyses of wire antennas do not take advantage of them. In this contribution a more direct approach to the problem is described, leading to a simpler implementation. Results are obtained for wire dipole and slot antennas of various cross-sectional dimensions and comparisons are made to results obtained using NEC.