基于异常反射型超表面的天线反射面设计

Design of antenna reflector based on abnormal reflective metasurface

在实际应用中有许多场合需要对电磁波的传播进行人工调控,传统的光学器件或者人工电磁介质都是采用三维结构,但传统的三维结构介质很难与其他器件或设备进行集成.利用相位非连续人工电磁表面则可以在传播路径的介质分界面上引入相位突变,进而实现人工调控电磁波.文章在此基础上在微波波段利用构造分界面相位梯度提出了一种异常反射型超表面的设计,用作天线反射面可将圆极化波高效地转化为交叉极化波,为微波段的电磁波人工调控提供了新的手段.根据广义反射定律及斜入射时相位突变修正设计的天线反射面,在X波段可以实现对入射电磁波的人工调控,并通过仿真分析验证了该设计方法的准确性,为人工电磁表面作为天线反射面提供了一种设计思路.

Accurate artificial manipulation of electromagnetic wave propagation is needed in many practical applications, while the traditional optical devices and artificial electromagnetic media adopt 3D structures which can be hardly integrated with other devices. By adjusting the transmission path to accumulate phase differences, a new way to control electromagnetic wave propagation and Generalized Snell’s law has been proposed. On this basis,to realize electromagnetic wave abnormal reflection in microwave region,the reflection-type metasurface based on phase gradient is adopted. Reflectors based on metasurface can efficiently convert circularly polarized waves into cross-polarized waves. According to the generalized reflection law and the modified phase difference at oblique incidence, the reflection EM wave by antenna reflector can be manually controlled in the X-band. The accuracy of the design method is verified by full-wave simulation analysis, which provides an idea for the metasurface as the antenna reflector.