基于电磁超表面的宽角扫描相控阵天线

Wide Angle Scanning Phased Array Based on Electromagnetic Metasurface

提出了一种基于电磁超表面的宽角扫描相控阵天线设计。其工作频率为19.6~21.2 GHz,扫描角度为二维±60°,相控阵天线单元为介质加载的波导口形式。为改善该相控阵的宽角匹配和辐射特性,用基于PCB工艺的电磁超表面替换常规的介质锥匹配结构。相控阵天线单元的仿真结果表明,超表面相控阵天线的有源反射系数更低。小规模阵列辐射特性的仿真结果表明,在±60°扫描角度范围内,超表面相控阵的最低增益相比常规相控阵提升了0.6 dB。中等规模阵列辐射特性的实测结果表明,常规相控阵在0°方位面扫描到60°时,辐射方向图会发生较大变形,天线辐射增益明显下降,而超表面相控阵的方向图仍保持完好,天线增益下降明显改善。上述仿真和实测结果证明,电磁超表面技术在改善相控阵天线宽角扫描特性方面可以发挥重要作用。

A wide-angle-scanning phased array antenna design based on electromagnetic metasurface is proposed.The working frequency is 19.6~21.2 GHz and the 2D beam steering angle is±60°.Dielectric filled waveguide is designed as the element of the phased array.In order to improve the wide angle impedance matching and radiation properties,metasurface based on PCB technique is used to replace the traditional dielectric pyramid structure.The phased array element simulation results show that metasurface phased array antenna achieves lower active reflection coefficients.The simulation results of radiation properties of small-scale array show that the minimum gain of metasurface phased array is 0.6 dB higher than that of conventional phased array within the±60°scanning range.The measured results of radiation properties of medium-scale array show that the radiation pattern of the dielectric-pyramid phased array is greatly distorted and the antenna gain obviously decreases when it scans from 0°in azimuth plane to 60°,while the metasurface phased array radiation pattern remains well,and the antenna gain exhibits obvious improvement.The above simulation and measured results show that the electromagnetic metasurface technology can play a critical role in improving the wide angle scanning properties of phased array antenna.