Investigation of cylindrical antennas containing aperture coupled shielded helical coils

Wire and tubular antennas often are loaded with lumped RLC circuits in order to control or alter one or more of the antenna's characteristics. Shielding these circuits forces the load to manifest itself to the antenna through a small aperture. This ensures that the laws of circuit theory may be used in an analysis to characterize the load, rather than Maxwell's equations, thereby simplifying computations.; In this thesis, techniques are developed for the analysis of a tubular antenna loaded with a shielded helical coil. Aperture and scatterer theory are utilized for the accurate solution for antenna current data. Conventional “lumped loads” are incorporated in models for an efficient solution for this data, and these load models enable one to include shielded coil data in a curved wire analysis. Both the accurate and efficient analyses involve a TEM impedance defined in a coaxial waveguide which is used to account for the shielded helical coil. End correction capacitances are required in the analyses as well. Finally, measurements are made to verify the accuracy of the analyses discussed.