Multi-physics Simulation and Modelling of Metasurfaces for Communications and Sensor Applications from Device to System

该研究计划的主要目标将是开发新的模拟技术，用于分析和设计各种应用中的超表面(MS)。该计划将处理从亚波长尺度长度到系统级别的多尺度建模框架的需求；以及多物理方法的重要性。MS是通过创建具有亚波长单位单元的准周期性排列的EM共振散射体的薄二维表面而形成的。细胞阵列的总响应可以理解为以频率相关磁化率为特征的紧急功能结构。由于内在现象的复杂性，MS的设计和分析是一个具有挑战性的领域。这笔赠款建议开发一套通用的数值工具，以促进MS及其使用的系统的设计和优化。将创建工具，以提供从单元单元设计到系统分析的能力。这一过程中的一个关键要素将是使用分层模型和模拟过程；从单元单元到系统。将为时变和非线性单元开发单元单元模拟工具。对于小区域传播研究，将为具有非线性/时变毫秒的系统开发一个工具，以处理涉及多个毫秒和大区域的散射和系统级问题，将开发两个工具，一个基于边界元方法，另一个基于增强射线跟踪。所有这些基础设施将结合多个物理方面的工作，重点是自洽的电磁、热学和电路模拟。这一全面的用于MS设计和系统优化的CAD基础设施将用于解决三个初步应用：1)针对无线(5G)信道容量增强的MS设计，2)MS伪装的MS实现，以及3)基于MS的窄带IR发射器。毫无疑问，融入MS元素的技术将对技术和社会产生巨大影响。这种变化发生的速度将强烈依赖于可用于MS设计的CAD工具以及利用这些工具的系统。在这个时间点上，这个CAD基础设施基本上是不存在的，而这笔赠款中提议的工作旨在提供它。提供这样一个CAD环境的技术影响将是非常显著的。它将使许多领域的创新成为可能，5G通信和传感器开发首先感受到影响。拟议工作的科学影响也将是相当大的。所提出的涉及非线性和时变元素的单元单元建模工作是一个开放的问题，将推动该领域的发展。这项工作的多尺度和多物理重点将创造大量新的科学材料来传播。最后，与实验者合作完成的应用工作将推进这些领域的知识库。

The primary goal of the research program will be to develop novel simulation techniques for the analysis and design of metasurfaces (MS) in a wide variety of applications. The program will deal with the need to have a multi-scale modelling framework from sub-wavelength scale lengths to the system level; and the importance of a multi-physics approach. A MS is formed by creating a thin two dimensional surface of quasi-periodically arranged EM resonant scatterers having a sub-wavelength unit cell. The total response of the array of cells can be understood as an emergent functional structure characterized by frequency dependent susceptibilities. Due to the complexity of the intrinsic phenomena MS design and analysis is a challanging area. This grant proposes to develop a set of general numerical tools to facilitate the design and optimization of MS's and the systems they are used in. Tools will be created to provide capabilities spanning from unit-cell design to system analysis.  A key element in the process will be the use of a hierarchal model and simulation process; building up from the unit cell to the system.   A unit-cell simulation tool will be developed for time-varying and non-linear cells. For small-region propagation studies a tool will be developed for systems with non-linear/time-varying MS. For addressing scattering and system level problems involving multiple MS and large regions, two tools will be developed one based on boundary element methods and the other on enhanced ray tracing. All of this infrastructure will incorporate multi-physics aspects with work focusing on self-consistent EM, thermal and electrical circuit simulation. This comprehensive CAD infrastructure for MS design and system optimization will be used to address three initial applications: 1) MS design for wireless (5G) channel capacity enhancement, 2) MS implementations of camouflage, and 3) MS based narrow-band IR emitters.   It is without doubt, that technologies incorporating MS elements will have a great impact on technology and society. The rate at which this change occurs will be strongly dependent on the CAD tools available for the design of MS's and the systems which exploit them. At this point in time, this CAD infrastructure is essentially non-existent and the work proposed in this grant aims to provide it. The technological impact of making such a CAD environment available will be very significant. It will enable innovation in many areas with impact first being felt in 5G communication  and sensor development. The scientific impact of proposed work will also be considerable. The work proposed on unit-cell modeling involving non-linear and time-varying elements is an open problem and will advance the field. The multi-scale and multi-physics focus of the work will create a large amount of new scientific material to be disseminated. Finally, the application work done in collaboration with experimentalists will advance the knowledge base for those areas.