A Wideband CP Agile and Beam Steering Reconfigurable Array by Presetting Geometric Phase

A 3 bit circularly polarized (CP) agile and beam steering reconfigurable array antenna is proposed, which features a significant axial ratio (AR) performance improvement for all states. By properly manipulating the array phase distribution, the radiation pattern of the designed $1 \times 8$ array antenna can be dynamically steered over a range of angles for each CP mode. Importantly, each beam state exhibits high CP purity and a wideband 3 dB AR bandwidth via pre-introducing geometric phase. The joint 3 dB AR relative bandwidth for all operating states is extended to $20.8 \%$. To demonstrate the proposed methodology, a prototype of the GPPT-based array is fabricated and characterized for all states. The measured results agree well with the simulated ones, thus validating the reconfigurability and the great advantages in broadening the AR bandwidth.