A comparison between tube-shaped and solid cylinder antennas

A comparison is made between center fed antennas consisting of a thin-walled circular tube and of a solid conducting cylinder of the same radius and length. The distributions of the surface current in the two cases are obtained by numerical solution of integral equations for the electric field strength in the extensions of the antenna surface. The current distribution and the radiation patterns are calculated for wavelength-to-radius ratios 10, 30, and 100, with the half length of the antenna equal to 0.23, 0.50, and 0.73 wavelengths.