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

随着通信数据速率的增加和移动电子设备的激增，对无线天线和无线电力传输的先进研究是至关重要的。超材料——具有奇异的电和磁特性的人造材料——为实现这类研究提供了一种手段。超材料可以操纵电磁场（光、无线电波、微波等）来产生奇怪的现象，比如看起来向后流动的波，以及当波碰到界面时“错误的方向”弯曲的波。随着整个电信行业在无线网络上的大量投资，天线性能的任何改进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以固定的角度保持高度定向的波束。这使得由此产生的无线链路可以在更宽的带宽上运行，并支持更高的数据速率，从而实现更快、更可靠的移动连接。超材料还可以用来将一根天线传输的能量集中到另一根天线上，以便在更远的距离上更有效地进行无线电力传输。提高效率是向在加拿大的每个家庭中安装无线电源迈出的一大步，它将彻底改变我们为设备供电和充电的方式。

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.