关键词: 超表面/
相位梯度/
宽角域/
雷达散射截面增强
English Abstract
Research of a wide-angle backscattering enhancement metasurface
Feng Mao-Chang,Li Yong-Feng,
Zhang Jie-Qiu,
Wang Jia-Fu,
Wang Chao,
Ma Hua,
Qu Shao-Bo
1.Department of Basic Sciences Air Force Engineering University, Xi'an 710051, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant Nos. 61501503, 61471388, 61331005) and the Natural Science Foundation of Shaanxi Province, China (Grant No. 2017JM6005).Received Date:29 May 2018
Accepted Date:02 July 2018
Published Online:05 October 2018
Abstract:To enhance backscattering, corner reflector and Luneburg lens are usually used. They can operate effectively in a broad angle range and also in a quite wide band. However, corner reflector as a typical structure of backscattering enhancement device, has obvious disadvantages in practical application. For example, it is usually made of metal material, which causes it to be too heavy and bulky. Luneburg lens is generally made of dielectric with strong loss and high cost, which is unfavorable for applications. Thus, it is necessary to explore a new way to realize wide-angle backscattering enhancement. In this paper, a phase gradient metasurface with wide-angle radar cross section (RCS) enhancement property is proposed and demonstrated, which consists of two phase gradients with equal magnitude but in opposite directions. Through designing a reflective phase profile along the surface, an equivalent wave vector can be generated, with doubled magnitude but in an opposite direction to the parallel component of the wave vector of the incident wave. At the incidence angles =-45 and 45, electromagnetic (EM) waves are reflected to the directions just opposite to the directions of incident waves. And at incidence angle =0, the incident EM wave is coupled into spoof surface wave and then guided to another region to decouple into a free space wave. These guarantee RCS enhancement property in a related angular domain. The polarization independent Jerusalem cross unit is used to design the phase gradient, and a wide-angle RCS enhancement metasurface is designed. The simulated results indicate that at the designed incidence angles, directions of the reflected waves are all opposite to the directions of incidence waves for both x and y polarized wave. In order to evaluate the RCS enhancement performances, the mono-static RCS of the designed wide-angle RCS enhancement metasurface is measured. Both the simulations and experiments are in good agreement with each other, and show that the designed metasurface obtains tremendous RCS enhancement performances in a wide-angle domain (-45-45) for both x and y polarized wave with frequencies ranging from 9 GHz to 12 GHz.
Keywords: metasurface/
phase gradient/
wide-angle/
radar cross section enhancement
