Direct time-domain techniques for transient radiation and scattering from wires

This is a tutorial introduction to transient electromagnetics, focusing on direct time-domain techniques. We examine physical, mathematical, numerical and experimental aspects of time-domain methods, with emphasis on wire objects excited as antennas or scatterers. Numerous computed examples illustrate the characteristics of direct time-domain procedures, especially where they may offer advantages over the more familiar frequency-domain techniques. These advantages include greater solution efficiency for many types of problems, the ability to handle nonlinearities, improved physical insight and interpretability, availability of wide-band information from a single calculation, and the possibility of isolating interactions among various parts of an object using time-range gating.