A novel miniaturised wideband antenna based on dual-layer metasurface (MS) is proposed in this study. It is composed of three metallic and two substrate layers. The top metallic layer is the MS whose unit is a square patch etched four interlaced quarter arc-shaped slots (PQAS). The middle metallic layer is a circular ring patch. The bottom metallic layer is the MS formed by the square metal ring (SMR). The top MS with PQAS and the bottom MS with SMR are combined which serve as a radiator and ground plane of the antenna directly, not a reflector. Thus, avoiding air layer, a low profile of 0.014 λ ₀ ( λ ₀ is the guided wavelength at 2.57 GHz) is realised. Meanwhile, the impedance bandwidth and gain of the antenna are improved. The measured results show that the −10-dB impedance bandwidth of the proposed MS antenna is from 2.57 to 4.12 GHz (the relative bandwidth is 46.3%). Furthermore, the maximum gain reaches 4.17 dBi.

中文翻译：

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基于双层超表面的低剖面小型化宽带天线

本文提出了一种基于双层超颖表面（MS）的新型小型化宽带天线。它由三个金属层和两个基底层组成。最上面的金属层是MS，其单位是刻有四个交错的四分之一弧形缝隙（PQAS）的方形贴片。中间金属层是圆环贴片。底部金属层是由方形金属环（SMR）形成的MS。带有PQAS的顶部MS和带有SMR的底部MS组合在一起，直接用作天线的辐射器和接地层，而不是反射器。因此，避免了空气层，低轮廓为0.014λ ₀（ λ ₀是在2.57 GHz处的引导波长）。同时，提高了天线的阻抗带宽和增益。测量结果表明，建议的MS天线的-10dB阻抗带宽为2.57至4.12 GHz（相对带宽为46.3％）。此外，最大增益达到4.17 dBi。