基于频率触发机制的电磁波调控方法与超材料可调器件研究

Using metamaterial gradient refractive-index devices to control electromagnetic fields has become an important research area in electromagnetics. Different from the utilization of the non-resonant parameter retrieval technique to construct broadband gradient refractive-index devices, this project will focus on the control of electromagnetic fields based on the frequency-triggered mechanism and its applications in the metamaterial tunable devices. The parameterized model will be proposed for controlling electromagnetic fields with frequency dispersive metamaterials, where the structural topologies of metamaterials will be devised to construct the versatility of tunable devices. As a result, an integrated design methodology will thus be developed for the frequency-triggered electromagnetic wave control, combining the retrievals of metamaterial structures and the manipulation of different functionalities of the gradient refractive-index devices. On this basis, we shall explore the metamaterial stealth technology through combining the cloaking design with the absorbing and the diffuse scattering based on the frequency-triggered mechanism, so that we can reduce the radar cross section at will over different frequency ranges with the proposed tunable stealth surfaces. We shall explore the metamaterial antenna array to synthesize radiation patterns that are capable of achieving multi-scale beamwidths and the large scanning angle based on the frequency-triggered mechanism, so that we can manipulate radiations freely at different working frequencies using the proposed tunable antennas.The research outcomes from this project will help to promote the theory of transformation optics for proposing more practical applications, and should offer new ideas for the design of metamaterial tunable devices.

通过超材料构建梯度折射率器件来调控电磁波的传播行为成为了现代电磁学的一个重要研究领域。与利用非谐振的参数反演方法实现宽频带梯度折射率器件不同，本项目将着力探索基于频率触发机制的电磁波调控方法及其在超材料可调器件设计中的应用。项目将构建频率色散超材料调控电磁波的参数化模型，形成面向可调器件多功能设计的超材料结构拓扑，实现由频率牵引的从超材料电磁结构反演到梯度折射率器件功能调控的一体化设计方法。在此基础上，研究基于频率触发机制的电磁波绕射与高效吸波及漫散射相结合的隐身表面，实现多频段可调控的目标雷达散射截面的有效缩减。研究基于频率触发机制的多尺度波束赋形与大角度波束扫描的天线阵列，实现多频带下天线辐射方向图的有效调控与波束覆盖。项目研究成果将有助于推动建立更为完善的电磁波调控理论与实用技术，并为超材料可调器件的设计提供新的研究思路。

本项目探索了基于频率触发机制的电磁波调控方法及其在超材料可调器件设计中的应用。项目研究实现了: 1、高性能微波传输与电磁透明器件，包括: 超传输级联弯折波导和具有大角度高效透波的ENZ超表面夹层。这些研究成果有助于构建新型波导滤波器及频率选择表面；2、新型超材料与超表面结构天线，包括：高增益超表面折叠天线，曲面共形超表面天线，多功能超材料平板天线及频率扫描超表面天线。这些研究成果有助于实现无线信号的精准高效收发；3、基于石墨烯的动态可重构超表面，包括：石墨烯超表面可重构隐身衣与可重构极化转化器。这些研究成果有助于开发新型低可探测性隐身表面。项目研究共发表SCI检索论文17篇，授权国家发明专利48项，完成了既定的研究目标和研究内容，研究成果将有助于推动建立更为完善的电磁波调控理论与实用技术，并为超材料可调器件的设计提供新的研究思路。