A Low Frequency Helical Antenna for Sub Surface Communication

The purpose of this paper is to develop a simple antenna structure of limited dimension suitable for low frequency and under ground communication. The closed wound helical antenna of length small compared to wavelength is found to be a better radiator compared to a linear antenna of same length. Field expressions for both dissipative and non dissipative media are calculated and tabulated. A chart is provided to study the reflection effect and a curve is plotted showing the relative strength of helical antenna with respect to the linear antenna. The assumption of uniform earth's characteristic is made through out the analysis