On the potential of using multimode reflectarray feeding horn antennas

Abstract

A new design for a reflectarray offset feed antenna is presented to cover the ka band satellite communications uplink (27.5-31 GHz). The design exploits a multimode feed horn antenna combined with a coaxial cavity to produce the required mixture of modes. The main benefit of such a feed antenna configuration is the low cross polarization and sidelobe level as an offset feed antenna. The antenna design details are presented and the radiation pattern characteristics are compared to a conical horn antenna with the same aperture size. The maximum aperture efficiency of the proposed design is compared to the multimode open ended waveguide design as well as the conical horn using different analysis methods proving at least 3% higher aperture efficiency.