The current in a parasitic antenna in a dissipative medium

A relatively simple analytic formula is derived for the current in a bare conducting cylinder of length
2h
and radius
a
when embedded in an isotropic homogeneous dissipative medium and excited by a periodic electric field with uniform amplitude and phase along its axis. In the derivation the same approximations are made as in an earlier analysis of the center-driven antenna for which complete experimental verification has been obtained. Computations are reported specifically for an antenna immersed in the ocean and excited by a field of very low frequency. The principal parameter is
h/\lambda
in the range from 0.03 to 0.23 at a frequency of 5 Hz, where
\lambda
is the wavelength in sea water. The effect of changes in the radius
a
are also shown successively with
a/\lambda
and
h/a
as the variable parameter. When the results of this paper are combined with those for the center-driven element, they provide the means for determining the response of a center-loaded dipole receiving antenna when immersed in a dissipative medium. Such an antenna is of interest in problems that relate to communication with submerged submarines and off-shore facilities.