Excitation of Current on an Infinite Horizontal Wire over the Earth by an Arbitrary Electric Dipole Source

: Excitation of propagating modes on a long horizontal wire over the earth by an arbitrary oriented dipole source is investigated. It is shown that with proper tailoring of sources, it is feasible to provide stronger excitation for either the structured-attached mode or the earth-attached mode relative to the others. In general, because the transmission-line (structured-attached) mode usually has higher attenuation in the frequency range of interest, larger percentage change in total current due to the scattering obstacles can be achieved when a smaller wire height is used. Numerical result for scattering due to dielectric obstacles modeling human bodies is included.