一种基于类表面等离子体激元的二维无限大天线阵的设计

A Two-dimensional Infinite Antenna Array Based on Spoof Surface Plasmon Polaritons

本文设计了一种基于支持类表面等离激元传播的周期金属柱底板的二维无限大天线阵.该天线阵周期单元由一个偶极子天线和4×4的周期金属柱底板构成.仿真结果表明:在工作频率为5GHz的情况下,天线阵可以在E面和H面都实现50°的扫描范围,并具有良好的阻抗匹配性能(S11<0.1).利用数值分析,我们发现类表面等离激元模式会被天线阵的高阶弗洛奎激发,该模式受到天线阵周期调制会从表面模式转变成泄漏模式,同时,该模式的色散曲线非常平,并且其电场在x和y方向具有良好的对称性,所以它能在多面广角度范围内都帮助天线阵辐射.

This paper presents a two-dimensional infinite antenna array with a periodic metal pillar ground plane supporting the propagation of Spoof Surface Plasmon Polaritons(SSPP).The unit cell of our antenna array consists of a dipole antenna and a 4×4 periodic metal pillar.The simulation results show that the proposed antenna array can achieve a scan angle of up to 50°in both E-plane and H-plane with the reflection coefficient S11<0.1 when the operating frequency is 5 GHz.Using numerical analyses,we reveal the mechanism of such excellent scanning properties.We find that the SSPP surface mode could be resonantly excited by a high-order Floquet mode from the array and that the surface mode could be converted into a leaky mode by the scattering of the array.At the same time,the dispersion curve of this SSPP mode is very flat,and electric field of this mode has good symmetry in the xand y directions.With the help of SSPP,the radiation performance is excellent in a wide range of scan angles.