In this paper, a multi-beam antenna based on annular slot and uneven metasurface is proposed. Through using the uneven metasurface formed by patches with different dimensions as radiator, the beam is focus on the direction of θ = 32°. As a result, the gain is improved. Furthermore, by employing compound double annular slot on the ground plane, the gain is further raised and the backward radiation is reduced. The realized antenna has a dimension of 65 × 65 × 4.862 mm³ (equal to 1.08λ₀ × 1.08λ₀ × 0.08λ₀). The results indicate that proposed antenna can operate from 4.95 to 5.42 GHz. In case that four ports of the antenna are excited respectively, four beams directed at (θ, ϕ) = (32°, 0°), (32°, 90°), (32°, 180°), (32°, 270°) can be observed.

中文翻译：

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基于环形缝隙和不均匀超表面的多波束天线

在本文中，提出了一种基于环形缝隙和不平坦超表面的多波束天线。通过使用由不同尺寸的贴片形成的不平坦超表面作为辐射体，光束聚焦在θ  = 32°的方向上。结果，提高了增益。此外，通过在地平面上采用复合双环形槽，进一步提高了增益，减少了后向辐射。实现的天线尺寸为 65 × 65 × 4.862 mm ³（等于 1.08 λ ₀  × 1.08 λ ₀  × 0.08 λ ₀）。结果表明，所提出的天线可以在 4.95 至 5.42 GHz 的频率范围内工作。如果天线的四个端口分别被激发，则四个波束指向（θ , ϕ ) = (32°, 0°), (32°, 90°), (32°, 180°), (32°, 270°) 可以观察到。