Ku波段电磁聚焦相位梯度超表面设计

Design of Ku-Band Electromagnetic Focusing Phase Gradient Metasurface

针对超表面在电磁聚焦透镜方面的应用,基于环形单元设计了一款应用于Ku波段的多层相位梯度超表面,并探讨了其在提高天线增益方面的应用。结合相位梯度原理,用环形单元构建了焦距为40 mm、单元数为13×13、尺寸为104 mm×104 mm×5.54 mm、焦径比为0.38的超表面电磁聚焦透镜。研究结果表明,垂直入射的平面波在焦距处横截面上的3 dB焦斑直径约为17 mm, 0°~15°角度入射的平面波聚焦性能稳定。另外,该超表面透镜的加载可使微带贴片天线辐射的球面波有效转化为平面波,在天线远场形成定向辐射,提高天线的增益。

For the application of metasurfaces in electromagnetic focusing lenses, a multi-layer phase gradient metasurface for Ku band is designed based on the ring unit, and its application in improving antenna gain is discussed. Combined with the principle of phase gradient, a metasurface electromagnetic focusing lens with a focal length of 40 mm, a unit number of 13× 13,a size of 104 mm× 104 mm× 5.54 mm, and a focal diameter ratio of 0.38 was constructed using a ring-shaped unit. The results show that the perpendicularly incident plane wave has a 3 dB focal spot diameter of about 17 mm on the cross section at the focal length, and the plane wave incident at an angle of 0° to 15° has stable focusing performance. In addition, the loading of the metasurface lens can effectively convert the spherical wave radiated by the microstrip patch antenna into a plane wave, form directional radiation in the far field of the antenna, and improve the antenna gain.