Date of Completion

January 1987


Engineering, Electronics and Electrical




The circuit and radiation characteristics of metallic antennas can be significantly altered by the introduction of dielectric loading. This dielectric loading may be a human body in the vicinity of the antenna, a sheath surrounding the antenna to insulate it from the ambient medium, or a core about which the antenna is wrapped. Previous analyses of dielectrically loaded wire antennas have been restricted as to the geometries of the antenna and/or the dielectric loading.^ This dissertation involves the determination of the electromagnetic response of several related dielectrically loaded thin-wire antenna structures. The study includes: (a) the evaluation of the near field of an insulated dipole in a dissipative dielectric medium, (b) a derivation of an integral equation for the current along an insulated helical antenna using the sheath helix model, and (c) an analysis of loop and helical antennas wrapped around solid dielectric cores via a moment method solution of two coupled integral equations. Comparisons of theoretical and measured input impedances and radiation patterns are also presented for dielectrically loaded loop and helical antennas. ^