Factorization of Antenna Efficiency of Aperture-type antenna: Beam Coupling and Two Spillovers
Factorization of Antenna Efficiency of Aperture-type antenna: Beam Coupling and Two Spillovers
复制标题
孔径型天线天线效率的因式分解：波束耦合和两次溢出
DOI：
10.1109/tap.2020.3044381
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发表时间：
2020
影响因子：
5.7
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Nagai;M. ; Imada;H. ; Okumura;T.
天线效率是射电望远镜最重要的观测指标之一，特别是在毫米波或更短的波长，即使是多波束射电望远镜。本文在标量波近似的框架下，分析了一个由两个孔径串联组成的无损耗天线。我们发现，天线的效率可以评估与第二口径上的场分布，天线的效率被分解为三个因素：波束耦合，传输溢出和接收溢出的效率。该分解方法适用于一般的波束波导口径天线，并能将口径效率与光瞳函数联系起来。我们用光学模拟在数值上证实了我们的因式分解。这种评估使我们能够管理的像差，是有用的多波束射电望远镜的设计。
Antenna efficiency is one of the most important figures of merit of a radio telescope for observations, especially at millimeter wavelengths or shorter wavelengths, even for a multibeam radio telescope. To analyze a system with a beam waveguide, a lossless antenna consisting of two apertures in series is considered in the frame of the scalar wave approximation. We found that the antenna efficiency can be evaluated with the field distribution over the second aperture, and the antenna efficiency is factorized into three factors: efficiencies of beam coupling, transmission spillover, and reception spillover. The factorization is applicable to general aperture-type antennas with beam waveguides and can relate the aperture efficiency to the pupil function. We numerically confirmed our factorization with an optical simulation. This evaluation enables us to manage the aberrations and is useful in the design of multibeam radio telescopes.