School of Electronic Engineering, Xidian University, Xi'an, 710071, People's Republic of China.
Sci Rep. 2017 Jul 18;7(1):5729. doi: 10.1038/s41598-017-06184-1.
Using the gradient phase discontinuities that meta-mirrors provide, we show that the incident wave can be reflected anomalously with a broad angle range of negative reflections. Such reversed behaviors promote the immediate applications for the planar meta-mirrors to steer the signals more arbitrarily and the convex meta-mirrors to focus and collimate electromagnetic fields. We practically implement these negative reflecting meta-mirrors through an arrangement of subwavelength ring patches and generate the desired phase distribution by also considering the incident angle. Finally, the experiments are carried out to verify the functionality of the convex meta-mirror firstly, and the performances of the planar meta-mirror are also tested by further building up a dual reflector system with the demonstration of obtaining the plane wave from the convex meta-mirror and then having the well collimated beam negative reflected by the planar meta-mirror. The proposed design should be readily applicable to a wide range of electromagnetic problems, especially for devising smart planar illusion devices, and highly directive antennas mounting on convex surfaces of various platforms.
利用超表面镜提供的梯度相位不连续，我们展示了入射波可以以宽角度范围的负反射异常反射。这种反转行为促进了平面超表面对信号的任意转向以及凸面超表面对电磁场的聚焦和准直的直接应用。我们通过亚波长环形贴片的布置实际实现了这些负反射超表面，并通过考虑入射角来产生所需的相位分布。最后，通过实验验证了凸面超反射镜的功能，进一步构建了一个双反射器系统，从凸面超反射镜获得平面波，并通过平面超反射镜将准直光束负反射，验证了平面超反射镜的性能。该设计应可广泛应用于各种电磁问题，特别是用于设计智能平面幻象装置和安装在各种平台凸面的高指向性天线。
