Wave manipulation using metamaterials for imaging, power concentration, and telecommunications

随着通信数据速率的提高和移动电子产品的激增，对无线天线和无线功率传输的高级研究的需求至关重要。超材料--具有奇异电磁特性的人造材料--提供了一种精确实现这类研究的手段。超材料可以操纵电磁场(光、无线电波、微波等)。以产生奇怪的现象，如波似乎向后流动，以及波在撞击界面时以“错误的方向”弯曲。随着整个电信业在无线网络上投入巨资，天线性能的任何改善都将产生广泛的影响。通过精心设计，超材料的奇异特性可以用来引导天线的辐射，使其能够在很大的频率范围内保持高度定向的波束在固定角度。这允许产生的无线链路在更宽的带宽上运行，并支持更高的数据速率，以实现更快、更可靠的移动连接。超材料还可以用来将一个天线发射的能量集中到另一个天线上，以便在更远的距离上更有效地进行无线能量传输。提高能效是朝着在加拿大家家户户使用无线电源迈出的一大步，并彻底改变我们为设备供电和充电的方式。 该探索计划的目标是研究波在超材料中的传播，以开发与成像、功率集中和电信相关的新型设备。超材料领域相对年轻；第一个示范性实验是在12年前进行的，我们仍然不了解它们的所有局限性。因此，继续研究超材料的电磁学对该计划是至关重要的。这些研究为我们提供了将超材料应用于负折射率透镜等新设备或改进现有技术所必需的见解，就像微波电路元件的小型化所做的那样。在接下来的五年里，这一目标将应用于导言中涉及的两个研究主题：使用天线阵列的近场功率集中，以及用于天线设计的变换光学超材料。这个项目将为研究生和本科生提供一个极好的机会，让他们参与到行业需求很高的主题的前沿研究中。 在过去的五年里，我开发了天线阵列，将电场和磁场聚焦到比工作波长更小的光点上。在超材料被发现之前，这被认为违反了基本的绕射定律，该定律规定，光的聚焦不能小于波长。我现在建议采用这种聚焦技术，将能量集中到亚波长点，用于材料的局部加热和无线能量传输应用。通常，近场功率传输和加热使用单个电源元件，因此多个元件的使用将使运行范围扩大两倍。 对于我的第二个关于高带宽定向天线的研究主题，我将在漏波天线上放置电磁参数逐渐变化的超材料层，以便将辐射波束重新定向到固定角度，并使工作带宽加倍。 对超材料物理的研究为进一步研究无线数据链路和无线能量传输天线提供了必要的理论基础。这些话题引起了电信业的极大兴趣，超材料提供了一个令人兴奋的机会，为这一领域做出重大贡献。

As communication data rates increase and mobile electronics proliferate, the need for advanced research into wireless antennas and wireless power transfer is critical. Metamaterials—artificial materials with exotic electric and magnetic properties—provide a means to achieve precisely this kind of research. Metamaterials can manipulate electromagnetic fields (light, radio waves, microwaves, etc.) to produce strange phenomena such as waves that appear to flow backwards and waves that bend “the wrong way” when they hit an interface. With the entire telecommunications industry invested heavily in wireless networks, any improvements in antenna performance will have a wide-reaching impact. Through careful design, the exotic properties of metamaterials can be used to guide the radiation of an antenna so it can maintain a highly directive beam at a fixed angle over a large frequency range. This allows the resulting wireless link to operate over a wider bandwidth and support higher data rates for faster and more reliable mobile connectivity. Metamaterials can also be used to focus the power transmitted by one antenna towards another in order to make wireless power transfer more efficient at larger distances. Improving efficiency is a big step towards putting wireless power sources in every home in Canada and revolutionizing the way we power and recharge our devices. The objective of this Discovery program is to study wave propagation in metamaterials in order to develop novel devices related to imaging, power concentration, and telecommunications. The field of metamaterials is relatively young; the first demonstrative experiment was performed 12 years ago and we still don’t understand all their limitations. It is therefore essential for this program to continue investigating the electromagnetics of metamaterials. These investigations provide us with the insights necessary to apply metamaterials to new devices like negative-refractive-index lenses or improve on existing technology as was done with the miniaturization of microwave circuit elements. Over the next five years this objective will be applied to the two research themes touched upon in the introduction: near-field power concentration using antenna arrays, and transformation-optics metamaterials for antenna design. This program will provide graduate and undergraduate students with an excellent opportunity to be involved in cutting-edge research on topics which industry holds in high demand. Over the last five years I developed antenna arrays to focus electric and magnetic fields to spots smaller than the wavelength of operation. Before the discovery of metamaterials, this was thought to violate a fundamental law of diffraction which states that light cannot be focused smaller than the wavelength. I am now proposing to adapt this focusing technique to concentrate power to subwavelength spots for localized heating of materials and for wireless power transfer applications. Typically, near-field power transfer and heating are performed with a single source element, so the use of multiple elements will extend the range of operation by an estimated factor of two. For my second research theme on high bandwidth directive antennas, I will place metamaterial layers with gradually changing electromagnetic parameters over a leaky-wave antenna in order to redirect the radiated beam at a fixed angle and double the operating bandwidth. Research into the physics of metamaterials provides the theoretical foundation necessary to pursue advanced research on antennas for wireless data links and wireless power transfer. These topics are of great interest to the telecommunication industry and metamaterials provide an exciting opportunity to make a significant contribution to this field.