Reconfigurable Transmitarray Design Approaches for Beamforming Applications
Reconfigurable Transmitarray Design Approaches for Beamforming Applications
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DOI：
10.1109/tap.2012.2213054
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发表时间：
2012-12-01
影响因子：
5.7
通讯作者：
Hum, Sean V.
中科院分区：
文献类型：
--
作者：
Lau, Jonathan Y.;Hum, Sean V.
无线传感和通信的最新进展已经导致需要能够进行高方向性可重构波束成形的天线。发射阵列已被证明是可行的架构，并出现了两种通用的设计方法：分层散射体方法和导波方法。在本文中，我们首先调查波束形成能力的分层散射体的方法，推广的方法使用阻抗表面。使用Floquet模式分析，我们表明，当这种类型的结构被用来产生一个笔形光束在大于20度的角度off-broadside，显着的旁瓣产生在大角度，无论孔径大小。接下来，我们提出了一个完全可重构的6 × 6 transmantarray基于导波的方法，实验演示了笔形波束扫描超过100 × 100度的窗口，以及成形波束合成，超过10%的分数带宽。从我们对这两种方法的研究得出的结论是，对于一般的波束形成应用，导波方法是上级，实现良好的带宽，扫描范围，插入损耗，和小的结构厚度，只有适度的制造复杂度。
Recent advances in wireless sensing and communications have resulted in the need for antennas capable of high-directivity reconfigurable beamforming. Transmitarrays have been shown to be viable architectures, and two general design approaches have emerged: the layered-scatterer approach and the guided-wave approach. In this paper, we first investigate the beamforming capability of the layered-scatterer approach, generalizing the approach using impedance surfaces. Using Floquet mode analysis, we show that when a structure of this type is used to produce a pencil beam at angles greater than 20 degrees off-broadside, significant side-lobes are produced at large angles, regardless of the aperture size. Next, we present a fully reconfigurable 6 x 6 transmitarray based on a guided-wave approach that experimentally demonstrates both pencil beam scanning over a 100 x 100-degree window as well as shaped-beam synthesis, over a 10 percent fractional bandwidth. The conclusion from our investigations into these two approaches is that for general beamforming applications, the guided-wave approach is superior, achieving good bandwidth, scanning range, insertion loss, and small structure thickness, with only moderate fabrication complexity.