Electromagnetic excitation of a thin wire: a traveling-wave approach

Presents an approximate expression for the scattered electric field caused by a polarized pulsed plane wave that is incident upon a straight thin-wire segment at arbitrary angles of incidence and polarization. In this expression, the scattered field consists of spherical waves caused by a direct current wave along the wire or by repeated reflections of such waves at the end points. At a sufficient distance from the wire, each of these constituents again reduces to a plane wave. Therefore, our expression is capable of describing multiple-scattering effects. This makes the model suitable for several "statistical" applications. The derivation is carried out in three steps. First an approximate expression is determined for the current along the wire in case of a delta-gap excitation. Second, an expression for the radiated electric field caused by this current is derived by applying a far-field approximation to the pertaining integral representation. In the third and final step, the scattered field due to a plane-wave excitation is identified as the cumulative effect of a continuous distribution of delta-gap sources. Thus, this field can be constructed from a suitable combination of delta-gap radiation fields.