Optimum Feeds for Reflectarray Antenna: Synthesis and Design

The synthesis and design approach for optimum reflectarray antenna feeds is introduced to maximize the obtained aperture efficiency. Feed antennas’ radiation patterns are synthesized to uniformly illuminate reflectarray apertures for both center- and offset-feeding configurations using an inverse problem approach. Moreover, circular horn antennas with coaxial cavities are designed, fabricated, and measured to realize the required radiation characteristics covering the satellite communication band X-Ku (10.7–12.7 GHz). Theoretical analysis of the proposed optimum radiation pattern and realization designs are presented in comparison to a conventional conical horn feed showing a potential enhancement of the aperture efficiency. Furthermore, full-wave analysis is used to compute the radiation patterns, frequency responses of the aperture efficiency, and beam squints for the proposed realization feed antennas.