Complex permittivity measurements of Karoo soil for the Square Kilometre Array

This paper investigates the electromagnetic shielding properties of soil taken from South Africa's Square Kilometre Array demonstrator site in the Karoo. The idea of exploiting soil to attenuate interference signals from cables and equipment rooms is explored. The complex permittivity of soil samples is extracted by measuring S-parameters and applying the iterative Baker-Jarvis extraction method. Various site and laboratory measurements were made to determine the level of attenuation of the Karoo soil. Good agreement between analytically predicted, numerically computed and site, as well as laboratory, measurements was achieved.