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Antenna design for ultra wide band communications and frequency selective surfaces.

机译：用于超宽带通信和频率选择表面的天线设计。

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摘要

In narrow band systems, the use of multiple antennas at the transmitter and the receiver, implementing what is traditionally known as Multiple Input Multiple Output (MIMO) system, has been shown to provide increased channel capacity as compared to a single antenna system.;Whereas traditional MIMO systems employ arrays of antennas that are separated by half a wavelength, MIMO systems implemented using orthogonal co-located loops and dipoles have been shown to be able to deliver the same capacity of traditional systems. In 2002, the Federal Communications Commission (FCC) approved the use of ultra wide band (UWB) devices operating in the frequency range 3.1--10.6 GHz. Since then efforts have been made to design ultra wide band systems for communications purposes. Ultra wide band systems promise increased data rates over short distances compared to traditional narrow band systems. Such systems can find applications in home networks, corporate wireless networks and also military communications. Since MIMO systems employing co-located antennas in the narrow band case deliver increased channel capacity as compared to a single antenna system, the design of co-located antenna systems for ultra wide band communication can potentially provide similar increases in capacity over a wide band.;The current work reports the design of such a vector antenna for an ultra wide band communications system. The vector antenna system consists of a loop antenna and two orthogonal bowtie antennas. It is shown that these antennas have a broad bandwidth, transmit and receive narrow pulses and have low mutual coupling. The performance of the antenna system is evaluated in a rich scattering environment and capacity calculations show that the channel capacity obtained is approximately equal to those employing a linear array of UWB antennas. It is also shown that the co-located vector antenna provides approximately a three fold increase in capacity as compared to a linear array of UWB antennas. An alternate design of a UWB vector antenna which is not co-located but distributed in space is also described. This antenna is smaller compared to the co-located antenna and provides similar increases in capacity.;Vector antennas can not only be used as active arrays but also as individual elements in passive arrays which is also investigated in this work. These arrays produce reflections at certain frequencies and allow transmission at others forming Frequency Selective Surfaces (FSS). Preliminary results including the reflection co-efficient curves for different geometries are reported. A vector antenna design of an FSS is described in detail which resonates at multiple frequencies producing a distinct signature.
机译：在窄带系统中，与传统的单天线系统相比，在发送器和接收器上使用多天线实现了传统上称为多输入多输出（MIMO）系统的事实，已证明可提供更大的信道容量。传统的MIMO系统使用的天线阵列间隔了半个波长，使用正交共置环路和偶极子实现的MIMO系统已显示出能够提供与传统系统相同的容量。 2002年，美国联邦通信委员会（FCC）批准使用工作在3.1--10.6 GHz频率范围内的超宽带（UWB）设备。从那以后，人们一直在努力设计用于通信目的的超宽带系统。与传统的窄带系统相比，超宽带系统有望在短距离内提高数据速率。这样的系统可以在家庭网络，公司无线网络以及军事通信中找到应用。由于与单天线系统相比，在窄带情况下采用并置天线的MIMO系统提供了增加的信道容量，因此用于超宽带通信的并置天线系统的设计可能会在宽带上提供类似的容量增加。 ；目前的工作报道了用于超宽带通信系统的矢量天线的设计。矢量天线系统由一个环形天线和两个正交的领结天线组成。结果表明，这些天线具有较宽的带宽，可以发送和接收窄脉冲，并且相互耦合度低。在丰富的散射环境中评估了天线系统的性能，容量计算表明所获得的信道容量大约等于采用UWB天线线性阵列的信道容量。还显示出，与UWB天线的线性阵列相比，位于同一位置的矢量天线的容量增加了大约三倍。还描述了不在同一位置而是在空间中分布的UWB矢量天线的替代设计。与共置天线相比，这种天线更小，并且容量也有类似的提高。矢量天线不仅可以用作有源阵列，而且还可以用作无源阵列中的单个元件，这项工作也在研究中。这些阵列在某些频率下产生反射，并允许在其他频率下透射，形成频率选择表面（FSS）。报告了包括不同几何形状的反射系数曲线在内的初步结果。详细描述了FSS的矢量天线设计，该设计在多个频率下谐振，从而产生独特的特征。

著录项

  • 作者

    Rajagopalan, Ajit.;

  • 作者单位

    North Carolina State University.;

  • 授予单位 North Carolina State University.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2008
  • 页码 85 p.
  • 总页数 85
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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