MEMS Reconfigurable Antennas Integrated with Adaptive Space-Time Processing Algorithms for Use in Wireless MIMO Systems

与自适应时空处理算法集成的 MEMS 可重构天线，用于无线 MIMO 系统

• 批准号: 0424454
• 负责人: Hamid Jafarkhani
• 金额: --
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424454&HistoricalAwards=false
• 关键词: MEMS; Reconfigurable; Antennas; Integrated; Adaptive

Intellectual Merit:The proposed research activity focuses on innovative concepts and technologies in the interdisciplinary areas ofelectromagnetic theory, communication theory, and radio frequency microelectromechanical systems (RF MEMS).This project will enable the design, the analysis, the fabrication, and the testing of multifunctional reconfigurableantennas operated in conjunction with adaptive space-time processing algorithms for use in novel wirelesscommunication systems. In particular, man-portable or vehicle mounted integrated adaptive multi-input multi-output (MIMO) microsystems used in environments with rapidly changing multipath conditions are targeted. Thegoal is to effectively exploit the theoretical gains in capacity and diversity offered by multiple reconfigurableantennas in order to minimize the gap between theory and practice. To accomplish this goal, the antenna arrayproperties (i.e. radiation pattern, the polarization, the operation frequency, and the input impedance) and adaptivetransmission signaling schemes are jointly optimized to adapt to the changing channel conditions. This jointoptimization procedure requires reconfigurable antenna elements capable of changing their properties and anadaptive algorithm that uses the interrelationships among antenna properties, transmission signaling schemes, andpropagation environment. Dynamic adaptation of the antenna properties is a recent UCI development representing amajor advancement in antenna design. In parallel, algorithms that combine beamforming and space-time coding touse partial channel information at the transmitter have also recently been developed. The innovative technology,which will be used to construct the reconfigurable antenna arrays, is a novel RF MEMS fabrication technologydeveloped in our group by a DARPA program. This technology is compatible with microwave laminate substratesallowing monolithic integration of MEMS with antenna elements on a printed circuit board. Due to its monolithicintegration capability, MEMS becomes a physical part of the antenna geometry, which is the key in achieving highdegree of multifunctionality and structural reconfigurability. The project is organized under the following mainsteps:1. Design, analyze, fabricate, and test a new class of antennas providing multifunctionality andreconfigurability in polarization, radiation pattern, operating frequency, and array configuration.2. Develop adaptive coding and signal processing schemes to take advantage of changing channelenvironments.3. Determine the links among antenna array properties, transmission signaling schemes (space-time coding,spatial multiplexing, and beamforming), and propagation environment (scattering density, disposition ofthe scatterers).4. Experimental investigation of the MIMO system established based on Steps 1, 2, and 3.5. Based on Steps 1, 2, 3, and 4 develop an adaptation algorithm through which Steps 1, 2, and 3 areintegrated together in order to maximize the resources available in MIMO channel at all times.Broader Impact:The multifunctional reconfigurable antenna concept in the proposed work surpasses the capabilities of and has adistinct difference with smart or adaptive antennas. In the literature, a smart or adaptive antenna refers to an antennaarray of elements with no intelligence combined with signal-processing capability through which the time domainsignals from or to the individual antenna elements are weighted and combined to optimize the radiation pattern inresponse to the signal environment. On the other hand, a reconfigurable antenna array consists of antenna elementseach of which has some intelligence. This intelligence stems from the ability of reconfiguring the physical structureof individual elements through which polarization, radiation and frequency properties of the array are changed.Thus, the elements in the reconfigurable antenna array have the ability to intelligently process the signals in spectraland angular domains adding to the already present time domain processing of the system. Due to the fundamentaldifference between smart antenna array, i.e. phased array, and a reconfigurable array, the theory describing thebehavior of the reconfigurable antenna arrays will be developed under this project. This will introduce a new sectionin the chapter of antennas and propagation in electromagnetics textbooks. There is also a need to develop the signalprocessing and communication theory that can benefit from this new class of antennas. Furthermore the integratedinterdisciplinary research philosophy adopted throughout this project will allow the PIs to develop and offerinterdisciplinary educational programs in the fields of electromagnetics, communications, and MEMS that willanswer the need for the new generation of engineers (in particular among minority students) at UCI who can dealwith and provide solutions to the emerging multifunctional micro-communication-systems.

智力价值：建议的研究活动侧重于电磁理论，通信理论和射频微机电系统（RF MEMS）跨学科领域的创新概念和技术。该项目将实现多功能可重构天线的设计、分析、制造和测试，并结合自适应时空处理算法，用于新型无线通信系统。特别是针对快速变化的多路径环境中使用的便携式或车载集成自适应多输入多输出（MIMO）微系统。目标是有效地利用多个可重构天线提供的容量和多样性的理论收益，以最大限度地减少理论与实践之间的差距。为了实现这一目标，天线阵列特性（即辐射方向图、极化、工作频率和输入阻抗）和自适应传输信令方案被联合优化，以适应不断变化的信道条件。这种联合优化过程需要能够改变其属性的可重构天线元件和一种利用天线属性、传输信令方案和传播环境之间相互关系的自适应算法。天线特性的动态自适应是UCI的最新发展，代表了天线设计的重大进步。与此同时，结合波束形成和空时编码利用发射机部分信道信息的算法最近也得到了发展。该创新技术将用于构建可重构天线阵列，是我们小组在DARPA项目下开发的一种新型射频MEMS制造技术。该技术与微波层压基板兼容，允许MEMS与印刷电路板上的天线元件的单片集成。由于其单片集成能力，MEMS成为天线几何结构的物理部分，这是实现高度多功能性和结构可重构性的关键。本项目主要分为以下几个主要步骤：设计、分析、制造和测试一种新型天线，在极化、辐射方向图、工作频率和阵列配置方面提供多功能和可配置性。开发自适应编码和信号处理方案，以利用不断变化的信道环境。确定天线阵列特性、传输信号方案（时空编码、空间复用和波束形成）和传播环境（散射密度、散射体配置）之间的联系。基于步骤1、2和3.5建立的MIMO系统的实验研究。在步骤1、2、3和4的基础上，开发了一种自适应算法，通过该算法将步骤1、2和3集成在一起，以便在任何时候最大化MIMO信道中的可用资源。更广泛的影响：提出的工作中的多功能可重构天线概念超越了智能或自适应天线的能力，并且与智能或自适应天线有明显的区别。在文献中，智能或自适应天线是指由没有智能的单元组成的天线阵列与信号处理能力相结合，通过对来自或到达单个天线单元的时域信号进行加权和组合，以优化响应于信号环境的辐射方向图。另一方面，由天线单元组成的可重构天线阵列具有一定的智能搜索功能。这种智能源于重新配置单个元件的物理结构的能力，通过这种结构可以改变阵列的极化、辐射和频率特性。因此，可重构天线阵列中的元件能够在系统已经存在的时域处理的基础上，在频谱和角域中智能地处理信号。由于智能天线阵列（即相控阵）和可重构阵列之间的根本区别，描述可重构天线阵列行为的理论将在本项目下发展。本文将在电磁学教科书的天线与传播章节中引入一个新的章节。还需要发展信号处理和通信理论，以便从这种新型天线中受益。此外，在整个项目中采用的综合跨学科研究理念将允许pi开发和提供电磁学，通信和MEMS领域的跨学科教育计划，这将满足UCI新一代工程师（特别是少数民族学生）的需求，他们可以处理并提供新兴多功能微通信系统的解决方案。