Finite Difference Time Domain Modeling of Fringe Waves

Abstract

A novel method is introduced for calculating fringe currents and fringe waves around the tip of a perfectly reflecting wedge under line source illumination. The time-domain fringe (non-uniform) currents are extracted with the finite-difference time-domain (FDTD) method. These currents are then fed into a free-space FDTD and fringe waves are excited. Alternatively, fringe waves are also obtained using the Green's function approach. The validation of the proposed method and the verification of the results are done against the physical theory of diffraction (PTD) as well as the method of moments (MoM). The factors affecting the accuracy are also discussed.