Recent advances in beam-scanning reflectarray antennas

A review of the recent advances in beam-scanning reflectarray antennas is presented in this paper. First, an overview of the two different methodologies for designing beam-scanning reflectarray antennas, namely aperture phase tuning and feed tuning techniques, is presented, and the advantages and limitations of both approaches are delineated. Next, recent developments in feed-tuned beam-scanning reflectarray antennas such as multifocal and partially illuminated apertures are reviewed and some numerical and experimental results are presented and compared. In comparison with other alternatives such as phase-tuned reflectarrays or phased array antennas, these passive beam-scanning reflectarrays are low cost and less complex, which makes them suitable choices for the new generation of high-gain beam-scanning antennas.