System Design and Aperture Efficiency Analysis

This chapter discusses the basic considerations for an efficient reflectarray system design. It outlines generalized formulations for computing the aperture efficiency and taper of planar reflectarray antennas and analyzes several reflectarray system designs. The chapter presents a generalized model for the radiation pattern of the feed antenna. In reflectarray antenna systems, the feed antenna position and radiation characteristics are one of the most influential measures in the design. Aperture blockage, mainly the feed blockage, is a physical characteristic that generally exists in reflectors and reflectarrays, where the feed antenna blocks some of the radiation. To minimize the effects of edge diffraction on the radiation performance of the antenna, the illumination level at the edges, that is, the edge taper (ET), should be low. Parabolic reflector antennas have long served as the most suitable antenna for high‐gain operation in both terrestrial and spaceborne applications. Reflectarray antennas are essentially built based on the concept of reflector antennas.