Advanced antennas for future wireless communication systems

无线通信系统的性能经常受到干扰、路径损耗、局部散射和多径传播的限制。因此，应该开发和部署可靠的天线系统，以提高未来无线通信系统的性能和效率。在这种情况下，具有超增益、可重构辐射方向图和宽带操作的下一代天线可以作为提高未来无线系统整体性能的有效解决方案。传统上，为了实现这一目标，已经使用了智能天线阵列。这种智能天线系统是基于传统的大量天线单元组合的设计策略。这些系统的后台基于模拟或数字信号处理器，可以根据接收到的信号自动优化辐射模式。这些方法的主要缺点是通过复杂的网络馈送大量天线，由于损耗导致效率降低。作为传统系统的替代方案，本研究计划旨在开发一种新型的先进天线，具有高增益，可重构的辐射模式，使用各种人造电磁材料，如有源频率选择表面（FSS），电磁带隙（EBG）结构和超材料。主要目标是设计和开发能够提供高增益、宽带操作和模式可重构性的先进新型天线。为了实现这些吸引人的特性，我们建议开发新的可调谐有源FSS， EBG或超材料结构。通过控制这些结构的电磁特性，可以控制增益、频带和辐射方向图，并通过电子方式重新配置。这些先进的天线将能够大大提高恶劣环境下的传输质量。有了这些特点，所提出的天线为未来的无线应用提供了巨大的潜力。为了实现这一具有挑战性的设计平台，建议的研究将集中在人工电磁材料的研究和表征上，包括敏捷FSS， EBG和超材料结构及其在开发具有超增益，宽带宽度和动态辐射方向图的新型先进天线中的应用。在本提案中，FSS， EBG和超材料结构由于其不寻常的，通常未被探索的电磁特性而提出了有趣的研究课题。对这些人造材料更深入的了解有助于优化微波和毫米波天线的物理特性，也可能是掌握其他有前途的技术的关键。此外，在微波和毫米波尺度上控制结构合成的能力将导致具有前所未有的物理和电学性能的新功能材料的发展。因此，该项目将有助于(i)活性FSS、EBG和超材料结构开发中涉及的分析、设计和实施机制；（ii）培养高度集中的FSS、EBG和超材料结构研究活动及其在先进天线设计和开发中的应用，符合加拿大高科技产业的具体需求；（iii）培养高素质人才，以应对我们现代社会的科技挑战。

The performance of wireless communication systems is often limited by interferences, path loss, local scattering and multipath propagation. Therefore, reliable antenna systems should be developed and deployed to enhance the performance and efficiency of future wireless communication systems. In this context, next generation antennas with ultra gain, reconfigurable radiation pattern and broad band operation can be used as an efficient solution for increasing the overall performance of future wireless systems. Traditionally, to achieve this objective, smart antenna arrays have been used. Such a smart antenna system is based on the conventional design strategy of combining large number antenna elements. The back-borne of these systems are based on analog or digital signal processors that automatically optimize the radiation pattern in response to the received signal. The principal drawbacks of these approaches are the high number of antennas fed through complex networks that leads to reduced efficiency due to losses. As an alternative solution to conventional systems, this research program aims to develop a new class of advanced antennas with high gain, reconfigurable radiation patterns using various artificial electromagnetic materials, such as active frequency selective surfaces (FSS), electromagnetic band gap (EBG) structures and metamaterials. The major goal is to design and develop advanced novel antennas that are capable of providing high gain, broadband operation and pattern reconfigurability. To achieve these attractive features, we propose the development of new tunable active FSS, EBG or metamaterial structures. By controlling the electromagnetic characteristics of these structures, the gain, frequency band and radiation pattern can be controlled and electronically reconfigured. These advanced antennas will be capable of drastically improving the transmission quality in hostile environments. With these features, the proposed antennas present significant potential for future wireless applications. To realize this challenging design platform, the proposed research will be focused on the study and characterization of artificial electromagnetic materials, including agile FSS, EBG and metamaterial structures and their applications in the development of new class of advanced antennas with ultra- gain, broad band width and dynamic radiation patterns. In this proposal, FSS, EBG and metamaterial structures present interesting research topics because of their unusual, often unexplored electromagnetic properties. A more profound knowledge of these artificial materials holds the promise of optimizing the physical properties of microwave and millimeter-wave antennas, and could also be the key to master other promising technologies. Moreover, the ability to control structural synthesis on the microwave and millimeter-wave scale will lead to the development of new functional materials with unprecedented physical and electrical properties. Therefore, this program will contribute to (i) analysis, design and implementation mechanisms involved in development of active FSS, EBG and metamaterial structures; (ii) foster highly focused research activities in FSS, EBG and metamaterial structures and their applications in design and development of advanced antennas , consistently with specific needs of the high technology Canadian industry, and (iii) train highly qualified personnel to respond to the scientific and technological challenges of our modem society.