基于透射超表面加载圆阵的双波束涡旋波天线

Dual-beam OAM Antenna Based on Circular Array Loaded with Transmissive Metasurface

为了提高通信系统的信道容量和频谱效率,本文提出了一种工作在X波段的透射超表面加载的八单元的均匀圆阵(UCA)双波束轨道角动量(OAM)天线,超表面分为三层结构,分别中间的金属层和上下的正交金属栅层,中间层将馈源辐射的y轴线极化入射的+1模态的涡旋电磁波转换为x轴线极化的出射的+1模态涡旋电磁波,同时基于相位叠加原理构成双波束超表面,将入射波分为两个不同方向(30°,0°)和(30°,180°)的出射波,并且出射涡旋电磁波相对于入射涡旋电磁波发散角降低了9°。该研究有望为基于多波束的轨道角动量复用和大通信容量的天线设计提供一种新的思路。

To improve the channel capacity and spectral efficiency of communication systems,this paper proposes a dual-beam orbital angular momentum(OAM)antenna operating in the X-band.The antenna utilizes a eight elements uniform circular array(UCA)loaded with a transmissive metasurface.The metasurface consists of three layers,including a central metallic layer and orthogonal metallic grating layers above and below it.The middle layer of the metasurface converts the y-polarized incident electromagnetic wave with+1 OAM mode,radiated from the feed source,into an x-polarized outgoing electromagnetic wave with+1 OAM mode.Additionally,by employing the principle of phase superposition,the metasurface forms a dual-beam configuration,which separates the incident wave into two different directions:(30°,0°)and(30°,180°).Furthermore,the divergence angle of the outgoing vortex electromagnetic wave is reduced by 9°compared to the incident vortex electromagnetic wave.This research holds the potential to provide a new approach for antenna design based on multi-beam orbital angular momentum(OAM)multiplexing and large communication capacity.