Measurement techniques for antennas in dissipative media

Methods used to simulate dissipative media environments for antennas are reported and special techniques developed to determine the electrical properties of antennas in such media are discussed. Tank systems for simulating infinite homogeneous isotropic media characterized by ratios of\alpha/\betain the range0 < \alpha/\beta < 1.0are described along with the apparatus for determining the constitutive parameters\sigmaand\epsilonof the media. A new device for measuring antenna input admittance is presented which permits a simple measurement of admittance over a broad frequency range where conventional methods are cumbersome in field use. Apparatus for measuring antenna current and charge distributions is described together with a discussion of the associated probing errors. Measured admittances and current and charge distributions are compared with current theories for thin wire linear and loop antennas in the dissipative media and are found to be in good agreement.