一种低RCS圆极化超表面天线阵列

A Low-RCS Circularly Polarized Metasurface Antenna Array

针对当前宽带圆极化辐射和低散射天线需求,提出一种低雷达截面积(Radar Cross Section,RCS)圆极化超表面天线阵列。天线阵列由线极化超表面天线单元组成,当天线辐射时,超表面被激励起新的工作模式,天线工作带宽得到拓宽;当天线被电磁波照射时,超表面的各向异性反射特性使得天线对于正交极化波的反射相位相反。将该超表面天线单元以正交方式组成2×2阵列,配合输入相位可以控制天线阵圆极化方式工作,天线的阻抗匹配频带为4.42~5.46 GHz。而正交的单元之间的反射形成对消,从而消除了镜面反射方向的RCS,相对于参考天线和金属面,新型天线阵列在4~8 GHz范围内RCS都有减缩效果。加工了一个4×4阵列实物并测试验证,实测结果与仿真结果取得了较好一致性。

To meet the demand of broadband circular polarization radiation and low scattering antenna,a novel metasurface antenna array with low radar cross section(RCS)and circular polarization is presented.The array is composed of linear polarizing metasurface antenna units.When the antenna radiates,the metasurface is motivated to create a new mode,and the working bandwidth of the antenna is widened.When the antenna is illuminated by plane waves,the anisotropic reflection characteristics of the metasurface make the reflect phase opposite to the orthogonal polarization wave.Forming a 2×2 array in an orthogonal way,circularly polarization can be achieved with tailored input phase and the impedance matching band is 4.42~5.46 GHz.In the scattering case,the reflection cancels each other between the orthogonal units,thus the RCS is reduced in the mirror reflection direction.Compared with the reference antenna and metal surface,the new antenna array has RCS within 4~8 GHz.A 4×4 array prototype is actually processed and tested,and the measured results are in good consistence with simulation ones.