Cross Polarization Characteristics of Cassegrain Confocal Parabolodal Antenna with Dielectric Feed Rod

The cross polarization properties of Cassegrain paraboloidal antenna with a dielectric rod as a plane wave source, fed by cylindrical metal waveguide is mainly studied in this paper. The proposed theory describes quite precisely the basic radiation characteristics and this is confirmed by the experiments with an X-band antenna, model of 0.8 m in diameter. The experimental and numerical results show a cross-polar levels less than ¿33 dB and ¿40 dB respectively in the 45°-plane. The studied antenna with such a polarization purity is very suitable for frequency re-use applications in the satellite and terrestial radio systems.