Introduction

Of the four forces in nature — strong, weak, electromagnetic, and gravitational — the electromagnetic force is the most technologically pervasive. Of the three methods of predicting electromagnetic effects — experiment, analysis, and computation — computation is the newest and fastest-growing approach. Of the many approaches to electromagnetic computation, including method of moments, finite difference time domain, finite element, geometric theory of diffraction, and physical optics, the finite difference time domain (FDTD) technique is applicable to the widest range of problems.