A Comparison Between two Different Techniques for Beam-scanning Reflectarray Antennas Design

The possibility of introducing beam-scanning capabilities in reflectarray (RA) antennas is becoming more and more important and several solutions have been proposed. Among them, a possible approach consists in using a passive RA and acting on the feed to achieve the beam-scanning. However, the fulfillment of the desired high gain constraints over the entire scanning range is still a challenging issue. Here, two different design techniques are considered and compared: a more conventional one, i.e. the bifocal design technique, and a more innovative approach, based on the use of an efficient evolutionary algorithm, the Social Network Optimization technique. The obtained results show the effectiveness of this last method, enabling the design of a RA with scanning capability over a wide angular range, outperforming the bifocal configuration.