Low-Cost Electrically and Mechanically Steerable Array Antennas for Internet-in-Sky Applications

适用于空中互联网应用的低成本电气和机械可控阵列天线

• 批准号: 0218805
• 负责人: Yasuo Kuga
• 金额: $ 8万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-10-01 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0218805&HistoricalAwards=false
• 关键词: Low; Cost; Electrically; Mechanically; Steerable

0218805KugaDespite the economical and technical problems with the current Iridium and GlobalStar and proposed Teledesic satellite systems, it is expected that a high-speed satellite-based internet will become practical in the near future. Iridium and GlobalStar do not have sufficient bandwidth to accommodate high-speed transmission of data. It is undeniable that the future anywhere-anytime high-speed internet access requires low-earth-orbit K or Ka-band satellite systems similar to the one proposed by Teledesic.One of the major problems with the proposed Teledesic system is the cost of the ground station antenna and control system. Unlike a geo-synchronous satellite, the low-orbit satellites move from horizon to horizon in 10 to 20 minutes. The antenna must be able to keep track of one or more satellite locations in order to obtain an uninterrupted connection. This is usually performed using phased array or mechanically steerable antennas. Unfortunately, the mechanically steerable antennas which use electro-mechanical actuators are usually bulky and prone to mechanical failures. The electronic phased array antennas are fast and no moving parts are involved, but they are very expensive.Their objective is to develop a low-cost steerable antenna using a novel phase shifter and electro-active polymer (EAP) actuators. In order to achieve this objective, the PIs propose the following four tasks.Task 1: Develop a low-cost phase shifter for a phased-array antenna using EAP.Task 2: Design a practical, low-cost phased-array antenna.Task 3: Develop a variable reflector surface antenna with EAP actuators.Task 4: Develop reliable and practical EAP materials and actuators.The phase shifter consists of a tiny mechanically movable dielectric element ontransmission lines. To move the dielectric block, they will use a newly developed EAP actuator which requires only 1-2V. An EAP actuator can also be used as a microwave switch to create a controllable delay line. The whole unit can be integrated with the patch antennas on a multi-layer PCB. The proposed antenna does not contain any solid state microwave switches or electromechanical devices. It can be fabricated inexpensively. They have already conducted the numerical simulations and results were obtained for several TL configurations. Another application of the EAP actuator is for a mechanically steerable antenna. A profile of a flexible membrane or plates can be controlled accurately with an array of EAP actuators. A desired radiation pattern can be quickly created by adjusting the surface profile. There are many technical challenges to realize the EAP-based antenna. To achieve their objective, they must develop reliable EAP materials and actuators.The PIs believe that the proposed low-cost antenna will be one of the key components to realize the "Internet-in-the-Sky". Although many aspects of this antenna have been tested and verified, they still need to work on several details. An EAP actuator is still in an infant state. To design the proposed antenna, they need a close collaboration between a material scientist who can design the EAP actuator and electrical engineers who can utilize the EAP actuator for the antenna applications.

0218805Kuga 尽管当前的铱星和全球星以及拟议的 Teledesic 卫星系统存在经济和技术问题，但预计基于卫星的高速互联网将在不久的将来变得实用。 Iridium 和 GlobalStar 没有足够的带宽来容纳高速数据传输。不可否认，未来随时随地的高速互联网接入需要类似于Teledesic提出的低地球轨道K或Ka波段卫星系统。Teledesic提出的系统的主要问题之一是地面站天线和控制系统的成本。与地球同步卫星不同，低轨道卫星在 10 到 20 分钟内从一个地平线移动到另一个地平线。天线必须能够跟踪一个或多个卫星位置，以获得不间断的连接。这通常使用相控阵或机械操纵天线来执行。不幸的是，使用机电致动器的机械操纵天线通常体积庞大并且容易出现机械故障。电子相控阵天线速度快，不涉及移动部件，但价格非常昂贵。他们的目标是使用新型移相器和电活性聚合物（EAP）执行器开发低成本可操纵天线。为了实现这一目标，PI们提出了以下四项任务。任务1：使用EAP开发用于相控阵天线的低成本移相器。任务2：设计实用的低成本相控阵天线。任务3：开发带有EAP执行器的可变反射面天线。任务4：开发可靠实用的EAP材料和执行器。移相器由一个微型机械结构组成。 传输线上的可移动介电元件。为了移动介电块，他们将使用新开发的 EAP 执行器，该执行器仅需要 1-2V。 EAP 执行器还可用作微波开关，以创建可控延迟线。整个单元可以与多层 PCB 上的贴片天线集成。所提出的天线不包含任何固态微波开关或机电装置。它可以廉价地制造。 他们已经进行了数值模拟，并获得了几种 TL 配置的结果。 EAP 执行器的另一个应用是机械操纵天线。柔性膜或板的轮廓可以通过一系列 EAP 执行器精确控制。通过调整表面轮廓可以快速创建所需的辐射图案。实现基于EAP的天线存在许多技术挑战。为了实现他们的目标，他们必须开发可靠的EAP材料和执行器。PI认为，所提出的低成本天线将是实现“空中互联网”的关键组件之一。虽然这款天线的很多方面都已经过测试和验证，但仍有几个细节需要下功夫。 EAP 执行器仍处于婴儿状态。为了设计所提出的天线，他们需要能够设计 EAP 执行器的材料科学家和能够将 EAP 执行器用于天线应用的电气工程师之间的密切合作。