In this paper, a near field focusing transmission metasurface (MS) based on polarization sensitivity is developed at microwave frequency. The MS unit cell has only three metal layers, which is less than the published dual‐polarized transmission structure. And the phase shifting range can cover 320° for x‐ and y‐polarized waves. The biggest bright spot of the focusing MS made of the proposed units is its changeable focus point by rotating the horn 0°–90° round its central axis: focusing switching between one and two focusing points. In addition, the developed MS has the following advantages: multifunctional, low sidelobe, high focusing efficiency, small size, wideband, and less layer number. The focusing relative bandwidth is 9.7%, and the maximum focusing efficiency is 30% at center frequency 15.5 GHz. The efficiency is higher than that of published results in transmission orthogonal polarization mode. The proposed MS has potential applications in medical treatment, noncontact sensing system.

中文翻译：

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基于极化灵敏度的多功能近场聚焦透射超表面

在本文中，开发了一种基于极化灵敏度的近场聚焦透射超表面（MS），它在微波频率下。MS晶胞只有三个金属层，比公开的双极化传输结构要少。相移范围可以覆盖x ‐和y的320°极化波。由所建议的装置制成的聚焦MS的最大亮点是其可变焦点，方法是将喇叭绕其中心轴旋转0°-90°：在一个和两个聚焦点之间进行聚焦切换。此外，已开发的MS具有以下优点：多功能，旁瓣低，聚焦效率高，尺寸小，宽带，层数少。聚焦相对带宽为9.7％，在中心频率为15.5 GHz时，最大聚焦效率为30％。在透射正交极化模式下，该效率高于已发表的结果。拟议中的MS在医疗，非接触式传感系统中具有潜在的应用。