Scattering by a thin wire parallel to a ground plane using the singularity expansion method

A thin wire parallel to a ground plane is analyzed using moment methods to find the complex natural resonant frequencies and modal current distributions. The resonant frequencies are found as functions of the wire radius and distance above the ground. The complex frequencies appear to be divisible into two classes: 1) those associated with the resonant length of the dipole and 2) those associated with interactions of the dipole and its image. For large dipole radii, the two classes interact and some anomalies, which appear, are investigated. The time domain response to a step-function plane wave is computed using the singularity expansion method and the results compare favorably with the Fourier transform solution.