Design and Performance Analysis of Hexagonal Reflectarray Unit Cell with Split Double Ring for Ku Band

This paper presents a novel design for a unit cell intended for Ku-band applications, featuring a grid size of 0.5λ × 0.5λ. The design incorporates a hexagonal patch and two split hexagonal rings, enhancing the antenna’s bandwidth and dynamic phase range at target frequencies. A comprehensive parametric study was conducted to assess the effects of substrate materials and foam/air thickness to optimize cost and performance. The design configurations were simulated using CST Microwave Studio on substrates with a thickness of 0.508 mm and 3 mm, employing Rogers RT5880 and air, respectively. The simulation results demonstrate that the proposed unit cell operates effectively across a frequency range of 13 to 18 GHz, with a wide dynamic phase range of 628 degrees and a bandwidth of approximately 14.28%. Furthermore, the reflection phase remains stable for incident angles up to 20 degrees in both elevation and azimuth planes, irrespective of the incident mode. These findings suggest that the proposed design offers a cost-effective and high-performance solution for reflectarray antennas in the Ku band.