A modified parabolic-cylindrical reflectarray antenna for wide beam scanning capablility

The parabolic cylindrical antenna and its reflectarray counterpart are well known for enhanced beam steering capability in the focal plane. However, the radiation performance degrades significantly for wide scan angles, for instance gain dropping and beam broadening, due to increased phase errors. In this paper, by exploiting the phase controlling capabilities in reflectarrays, an improved reflectarray based on conventional parabolic cylinder type designs but with optimized phases is proposed. The design of a Ka-band microstrip reflectarray antenna fed by a rotatable array is presented. The preliminary calculated results show that after optimization the scanning range can be significantly increased while maintaining similar radiation characteristics.