Comparison of Multibeam Radiation Performance of Parabolic and Spherical Reflector Antenna

Multibeam radiation patterns are requested at the broadcasting satellite antenna. In this paper, multibeams radiation characteristics are compared between the conventional parabolic and the spherical reflector antenna using similar specifications. Reflector diameter of 35.8 wavelength at 12.5GHz is selected. A conical horn is employed for the feed radiator. Multibeam radiation patterns are obtained by using an Electromagnetic Simulator FEKO. The results show that the gain degradation at 20 beam width shift becomes around 3.2dB for a parabolic reflector antenna and 0.7dB for a spherical reflector antenna with the F/D = 0.698 antenna configuration.