Design of Single-Feed Reflectarrays with Asymmetric Multi-Beams

This paper investigates the feasibility of designing reflectarray antennas with asymmetric multiple beams. The conventional design methods for multi-beam reflectarrays are reviewed and the limitations of these approaches are discussed. In the next stage, the particle swarm optimization method is implemented for multi-beam reflectarray antenna designs and various reflectarrays with asymmetric beam directions and gain levels are studied. It is demonstrated that the particle swarm optimization is a suitable approach for designing complicated multi-beam reflectarray antennas where conventional design approaches fail to achieve a good performance.