CAREER: Near-The-Horizon Steerable Phased Array Antennas with Reconfigurable Inter-Element Spacing and Radiation Patterns

随着移动的和无线通信需求的不断增长，天线技术的进步成为必然，而天线是任何无线系统的关键部件。特别地，相控阵天线在下一代移动的通信以及用于军事、空间和卫星的无线通信中受到追捧。拟议的研究旨在从根本上推进设计由可重构辐射元件组成的最先进相控阵天线的技术途径和方法，具有广角扫描能力，自适应孔径分布和多功能辐射特性。它在国土安全、无人驾驶汽车、监控、遥感、汽车雷达、智能交通等领域的移动的和无线系统中有着广阔的应用前景。除了对新兴的无线通信产生直接影响的研究进展外，该项目还将带来重要的长期社会效益。为了解决天线工程师和科学家明显短缺的问题，拟议的工作将通过整合天线和应用电磁学的教育和研究，为培养学生做出重大贡献，从而维持美国在先进无线通信领域的竞争力。拟议工作的教育部分的重点是在亨茨维尔（UAH）的亚拉巴马大学的本科生和研究生水平开发跨学科的天线课程。外展计划是促进当地社区大学参与天线研究活动，让K-12学生参加在UAH举行的研讨会，并吸引年轻学生，特别是来自代表性不足的群体，学习科学，技术，工程和数学（STEM）。拟议的研究旨在解决具有可重构辐射特性的近地平线波束扫描天线的现有挑战，第一次研究了具有电子控制单元间间距的自适应相控阵天线。这些是通过利用自适应天线元件来实现的，自适应天线元件可以促进开发用于零操纵和广角波束扫描的辐射匹配元件，而不损害期望的天线辐射特性。更重要的是，天线元件通过改变它们的有效辐射源来提供独特的特征，从而允许在不使用任何机械装置的情况下对阵列元件间距进行电子控制。所提出的研究提供了一个基础，以进一步测试虚拟阵列天线的假设，因为所提出的相控阵天线的每个元素可以虚拟地从其物理中心位移。这使得新的水平的实时控制的阵列孔径字段通过重新配置在元件级的幅度图案和相位分布，以及在阵列级生成广角扫描光束和自适应辐射图案。这将反过来导致多功能，降低旁瓣电平，并抑制栅瓣在所提出的阵列天线。提出的天线重构新技术对下一代自适应相控阵天线具有很好的应用前景。

The increasing demand of mobile and wireless communications necessitates technology advancements in the antenna, which is a pivotal component of any wireless system. In particular, phased array antennas are sought after in next generation mobile communications as well as wireless communications for military, space, and satellites. The proposed research aims to fundamentally advance the technical approach and methodologies of designing state-of-the-art phased array antennas consisting of reconfigurable radiating elements, featuring wide-angle scanning capabilities, adaptive aperture distributions, and multi-functional radiation properties. It has promising applications in mobile and wireless systems for homeland security, unmanned vehicles, surveillance, remote sensing, automotive radars, intelligent transportation, etc. In addition to the research advancements that will have immediate impacts on the emerging wireless communications, the project will also bring important long-term societal benefits. To address the noticeable shortage of antenna engineers and scientists, the proposed work will significantly contribute to the training of students by integrating education and research in antennas and applied electromagnetics, thus sustaining the U.S. competitiveness in advanced wireless communications. The educational component of the proposed work is focused on developing inter-disciplinary antenna courses at both undergraduate and graduate levels at the University of Alabama in Huntsville (UAH). The outreach plan is to foster local community college participation in antenna research activities, engage K-12 students in workshops held at UAH, and attract young students, particularly from underrepresented groups, to study Science, Technology, Engineering, and Mathematics (STEM).The proposed research aims to address existing challenges of near-the-horizon beam scanning antennas with reconfigurable radiation characteristics and, for the first time, investigate adaptive phased array antennas with electronically controlled inter-element spacing. These are realized by utilizing adaptive antenna elements that can facilitate developing radiation matched elements for null steering and wide-angle beam scanning, without compromising desired antenna radiation properties. More importantly, the antenna elements provide unique features through changing their effective source of radiation, and thus allowing electronic control of the array element spacing without using any mechanical means. The proposed research provides a basis to further test the hypothesis of virtual array antennas, since each element of the proposed phased array antenna can be virtually displaced from its physical center. This enables new levels of real-time control of the array aperture fields by reconfiguring both amplitude patterns and phase distributions at the element level, as well as generating wide-angle scanned beams and adaptive radiation patterns at the array level. This will in turn lead to versatile functionality, reduced sidelobe levels, and suppressed grating lobes in the proposed array antenna. The proposed new technique of antenna reconfiguration has promising potential for the future generation of adaptive phased array antennas.