A New Design for a Multiband Feed System using Dielectric Rods as Radiating Elements

A multiband dual linear polarized feed system to be used on earth station antennas for propagation experiments has been developped, operating simultaneously at the 12.5 20 and 30 GHz beacon frequencies of the Olympus satellite. Due to the original feed configuration it is possible to obtain a broadband system for each beacon frequency and moreover to align the polarization in any angular range continuously; this is obtained using 180 deg phase shifters (polarizers) and rotary joints. In addition the feed system provides tracking capabilities obtained with an easy mechanical implementation of the monopulse classic schematic diagram; in such a way the adopted design solution leads to a very compact tracking network. Criteria design and results will be described along the paper.