Adjusting aperture illumination on dual reflectarray antennas for maximum aperture efficiency

Presented is a novel method for controlling aperture amplitude distribution on dual reflectarray antennas with the aim of achieving maximum aperture efficiency. This has been performed by appropriately shaping the sub-reflectarray which gives optimum illumination on the main reflectarray aperture. Applying this technique resolves the inherent deficiency of reflectarrays; which is the impossibility of controlling elements amplitude on the reflectarray aperture. In this regard, it has been shown that using this feature, the aperture efficiency of a classic dual reflectarray antenna can be enhanced significantly by optimally shaping the sub-reflectarray radiation pattern. Theoretical analyses demonstrate aperture efficiency of more than 84% which is an improvement of about 12% in antenna aperture efficiency comparing with conventional dual reflectarray antennas.