Controlling microwave radiation from sources by design of their environment

该项目将研究使用超材料和超表面优化天线性能，如效率和方向性。改进天线设计的其他驱动因素包括需要最小化重量、厚度和横截面积，以扩展带宽并降低成本。该项目将专注于设计新型超颖表面，赋予人工边界条件，以实现上述目标。超表面将概念化，设计，建模，制造和实验测试最初没有参考天线。将考虑提供宽带频率响应的多层和多域设计-这可能需要这些表面内的谐振元件的小型化，并且这可以通过考虑复杂的几何形状或使用高折射率材料来获得。该项目的第二阶段将看到元表面与最简单的辐射器/天线设计相结合，以了解两者之间的耦合。然后，研究人员将开发元表面设计，以匹配辐射元件中的电流分布，或者以其他方式操纵天线性能和功能：这可能包括考虑各向异性表面。一旦这是undertsood，我们将考虑更复杂的“现成的”和定制的设计的辐射元件，以最大限度地提高效益的组合表面辐射antnnna系统。天线的兴趣，列奥纳多是非常宽带覆盖几十GHz类似-他们发现在民用和国防应用，如无线通信和航空。这个学生奖学金的新奇在于应用超材料来优化天线性能。很有可能在学生期间研究或开发有源或可重构的超材料。极化操纵（以最大限度地有效利用天线孔径）也是感兴趣的，并在该项目的范围内。在国防应用中，雷达截面（RCS）也很重要，因此也将被考虑用于有利的天线和超材料选项。

This project will investigate the use of metamaterials and metasurfaces for optimising antenna performance, such as efficiency and directivity. Other drivers in improving antenna design include the need to minimise weight, thickness and cross-sectional area, to extend bandwidth and reduce cost.The project will focus on the design of novel metasurfaces that impart artificial boundary condtions in order to achieve the ambitions above. Metasurfaces will be conceptualised, designed, modelled, fabricated and experimentally tested initially without reference to an antenna. Multilayered and multidomained designs will be considered that provide a broadband frequency response - this will likely requrie the minaturisation of the resonant elements within these surfaces, and this can be obtained by considering complex geomtries or the use of high-index materials. The second stage of the project will see the metasurfaces combined with the simplest radiator / antenna designs in order to understand the coupling between the two. The researcher will then develop the metasurfaces designs in order to match the current distribution in the radiating element, or to otherwise manipulate the antenna performance and functionality: this might include the consideration of anisotropic surfaces. Once this is undertsood, we will then consider more complex 'off-the-shelf' and bespoke designs of the radiating element in order to maximise the benefits of the combined surface-radiator antnnna system.The antennas of interest to Leonardo are very broadband covering tens of GHz similar - they find application in civil and defence applications such as wireless communication and aviation. The novelty of this studentship is in the application of metamaterials to optimise the antenna performance. It is quite possible that active or reconfigurable metamaterials are investigated or developed in the course of the studentship. Polarisation manipulation (to maximise the efficient use of the antenna aperture) is also of interest and within the scope of the project. In defence applications, radar cross-section (RCS) can also be important and so will also be considered for favoured antenna and metamaterial options.