Measurement Results of Broadbanding a Reflectarray Antenna by Controlling Phase Center of Primary Radiator

Reflector array antenna consists of a horn antenna as the primary radiator and a reflector mirror made of planes. The antenna has the disadvantage of narrow bandwidth due to phase errors on the aperture plane at frequencies other than the design frequency. Various studies have been conducted to improve the narrow-bandwidth characteristics, but the gain reduction due to phase error is a major bottleneck in reflector array design. In this study, we investigate the residual aberration, which is considered to be inevitable in the characteristics of reflective array antennas, for wideband reflective array antennas, focusing on the primary radiator in the reflective array antenna. A method to correct the residual aberration by controlling the phase center position of the primary radiator is proposed, and a wideband reflectarray antenna using this method is described and its effectiveness is verified from measurement results.