This paper introduces a compact, low-profile, low-loss, all-metal reflectarray antenna operating at 2.45 GHz. It features a novel unit cell with a triple split-ring slot configuration, where the reflection phase is controlled by adjusting sector angles. The design is etched onto a single metal plate, eliminating dielectric substrates and their losses. The 9×9 array, with a 540 × 540 mm² aperture and a height of 0.1225λ (15 mm), includes rim metallic walls to boost gain and radiation performance. A center-fed TE₁₀ rectangular waveguide at a 335 mm focal distance illuminates the array, directing the main beam at broadside. Full-wave simulations show a 21.1 dB gain, 52.3% aperture efficiency, −14.6 dB sidelobe level, and 7.8% 3-dB gain bandwidth. Compared to dielectricbased reflectarrays, this metal-only design offers lower loss, higher radiation efficiency, and a compact manufacturable structure. Its robust construction enhances power-handling and thermal stability, making it ideal for highpower applications like wireless power transfer. |
