Chu Hui, Zhao Hanjun, Li Peng, Guo Yong-Xin
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing, China.
Department of Electrical Engineering, City University of Hong Kong, Hong Kong SAR, China.
Nat Commun. 2024 Nov 29;15(1):10375. doi: 10.1038/s41467-024-54672-6.
Programmable metasurfaces (PMSs) exhibit great potentials in target detection techniques, because they can take actions to change channel propagation characteristics which introduces further degrees of freedom for system optimizations. However, responses of most traditional PMSs are sensitive to incident angles of impinging electromagnetic waves, resulting in a failure of angular estimation to dynamic targets coming from different directions. Herein, by proposing a fully resonant structure and introducing a mode-alignment technology, we report an isotropic angle-insensitive PMS whose phase response is stable with respect to different incident angles in both elevation- and azimuth-planes. A radar scheme that uses such a PMS as a periscope is also demonstrated, to detect drones in a non-line-of-sight (N-LOS) scenario which usually happens in an urban environment. Our proposed scheme enables those targets even falling in shadow areas caused by high buildings to be successfully detected and tracked, which shows promising potentials in N-LOS target detections.
可编程超表面（PMS）在目标检测技术中展现出巨大潜力，因为它们能够采取行动改变信道传播特性，这为系统优化引入了更多自由度。然而，大多数传统PMS的响应对入射电磁波的入射角敏感，导致对来自不同方向的动态目标进行角度估计失败。在此，通过提出一种全谐振结构并引入模式对准技术，我们报道了一种各向同性的角度不敏感PMS，其相位响应在仰角和方位角平面内对于不同入射角都是稳定的。还展示了一种将这种PMS用作潜望镜的雷达方案，以检测通常发生在城市环境中的非视距（N-LOS）场景中的无人机。我们提出的方案能够成功检测和跟踪那些甚至落在由高楼大厦造成的阴影区域中的目标，这在非视距目标检测中显示出了广阔的潜力。
