A metasurface-based wideband bidirectional same-sense circularly polarized antenna

This article presents a wideband bidirectional same-sense circularly polarized (CP) antenna based on metasurface structure. The antenna consists of a rectangular slot and two identical layers of periodic metallic plates as metasurfaces (MSs). The MS structure is formed by 16 unit cells of truncated-corner patches arranged in 4 x 4 configuration. For bidirectional beam realization, the MSs are positioned on both the front and back sides of the primary radiating slot. In the proposed design, the MSs act as a polarization conversion structures, which convert the linearly polarized wave produced by the rectangular slot to the CP wave. The final antenna has a profile of 0.13 lambda( o) and lateral dimensions of 0.86 lambda( o) x 0.67 lambda( o) at the center operating frequency. Measurements show that the proposed design radiates left-hand CP radiation for both front and back directions over wide operating bandwidth of 14.3% (5.2-6.0 GHz). In addition, the average gain value is about 4.2 dBi and the radiation efficiency is always better than 83% across the operating band. To the best of authors' knowledge, the proposed one shows a state-of-the-art operating bandwidth in comparison with other reported designs.