A Study on the Structural Optimization of Aperture Efficiency for Reflectarrays

In this study, structural optimization of the aperture efficiency of a high-gain reflectarray antenna based on a metasurface was conducted. The performances of various configurations were compared and analyzed, including unit cell arrangements under various in-phase criteria, unit cell arrangements considering the reflection phase with incident angle differences, application of a PEC wall at the outer boundary of the metasurface, and removal of the central patterns. The aperture efficiency and side-lobe level were adopted as the main performance indicators for the designed reflectarray antenna, and electromagnetic simulations were conducted to quantitatively evaluate the impact of each structure on the antenna characteristics. The full-wave simulation results showed improved aperture efficiency and suppressed side lobe levels in specific environments and configurations. The designed reflectarray antenna was fabricated using the proposed structural optimization process, and measurements were conducted. As a result, the measured radiation characteristics exhibited close agreement with the full-wave simulation results, thereby confirming the validity and effectiveness of the designed reflectarray antenna.