A low-profile multibeam antenna based on artificial magnetic conductor metasurface

In this paper, a low-profile high‑gain multibeam antenna based on a 5 × 5 artificial magnetic conductor (AMC) metasurface is proposed for potential sub‑6 GHz 5G applications. Instead of conventional full‑array etching, the four corner units of the AMC are loaded with cross-shaped slots, which effectively suppress sidelobe and backlobe radiation while improving directivity. The AMC metasurface enables a low profile and enhances the overall gain. The fabricated antenna has a compact dimension of 1.36 λ0 × 1.36 λ0 × 0.04 λ0 at 5.1 GHz. When the four ports are excited individually, the main beams are directed at (θ, φ) = (17°, 270°), (17°, 180°), (17°, 90°), and (17°, 0°), respectively. The measured gain reaches 9.45 dBi, demonstrating a clear improvement over conventional multibeam designs in both profile and radiation performance.