Optimized Conformal FDTD (2, 4) Method for Calculating Reflected and Diffracted Electromagnetic Fields of Perfectly Conducting Wedges

An optimized conformal finite-difference time-domain (FDTD) (2, 4) method is proposed for calculating reflected, diffracted, and total fields of two- and three-dimensional (2- and 3-D) perfectly conducting (PEC) wedges with an electromagnetic pulse (EMP) incidence, where one low-cost coefficient-modification (CM) technique is implemented for effectively reducing its numerical dispersion error. For the 2-D geometries, both reflected and diffracted fields are extracted from the whole calculation domain of FDTD (2, 4), and excellent agreement is achieved between the calculated diffraction coefficient and the analytical one obtained by high frequency approximation method of UTD. While for the 3-D wedges, even with the coarse FDTD cells adopted, such an optimized method still possesses the capability for getting more accurate diffracted fields in comparison with the conventional FDTD.