An experimental investigation on the behavior of the dipole antenna near the interface between the conducting medium and free space

An experimental study was made of the driving-point admittance and the relative amplitude and phase distributions of the current for a dipole antenna near and parallel to the interface between the conducting medium and free space. (The antenna was always located in the conducting medium, unless otherwise specified.) The depth of the antenna from the interface was varied from to 0. The loss tangent of the conducting medium was varied from 0.036 to 8.8, a range which includes a variety of media such as poor insulators, the ionosphere, plasmas, dry earth, wet earth, lake water, and sea water. The antenna height in radians was varied from through . Comparisons were made, wherever possible, between the characteristics of the dipole antenna in the half space and in a space completely filled with the dissipative medium. The driving-point admittances in the limiting case are in good agreement with the available theories by King and Harrison [1], and Wu [2], which have already been verified experimentally by Iizuka and King [3]. Since all measured results are given in terms of dimensionless parameters such as , and , they may be applied to any combination of conductivity, frequency, dielectric constant, and distance of the antenna from the interface [4].