Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange
Abstract
The aim of this thesis is to investigate the nature of the electromagnetic wave transmitted from a loop antenna enclosed by a spherical insulating cavity which is immersed in a conducting medium. The nature of the electromagnetic wave in a conducting medium generated by a loop antenna has been studied. Based on the formulas derived, a low frequency wave suffers less attenuation than a high frequency wave. This effect is very noticeable when the conductivity of the medium is high, such as with sea water. AT low frequencies the power radiation is small compared with the power supplied to the loop antenna. The selection of frequency and power of a transmitter depends upon the conductivity of the medium, the size of the loop antenna, and the size of the insulating cavity. However, high frequencies are inefficient, because at these frequencies most of the power is dissipated as heat in the vicinity of the antenna. Furthermore, the frequency cannot be too low because of a great amount of power required. In addition, size of a low frequency transmitter is generally larger than a high frequency transmitter. In some practical applications size is very important and consequently larger transmitters cannot be used
