Radiation characteristics of the short dielectric rod antenna: A numerical solution

The problem of the dielectric rod antenna is studied numerically. The surface integral equation is used to simulate the problem in its actual form. From the surface currents induced on the antenna surface, the far-field radiation patterns are calculated. Different parameters are considered, such as the extension of the dielectric from the waveguide aperture, the waveguide and the dielectric diameter, the dielectric constant and finally the effect of shaping of the dielectric end. The performance of the antenna as a feed for the reflector antenna is also studied by calculating the gain factor, spillover efficiency and the phase center location of the feed. Some of the results are compared with the available experimental data of Dombek. The agreement is found to be excellent.