全息天线的研究与设计

发布时间：2018-05-11 21:38

本文选题：原型全息天线 + 小型化　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：全息天线的研究已成为一大热点,全息的概念来源于光学,但在微波频段发挥了其更大的应用前景,其结构简单,馈源形式灵活,以新的理念——干涉,来构建散射器结构,进而产生具有目标辐射特性的波束。本文从全息的研究现状及目前研究中所存在的问题着手,确定了全息的研究背景;经过分析,确定了本文的主要工作及研究思路,根据核心工作确定我们的研究方法和需要的辅助工具,核心工作主要包括以下几个方面的内容。首先,从全息天线的结构和理论出发,计算了馈源天线与目标辐射特性的干涉场,得到干涉图样;采用金属条带的方式近似构建干涉图样——全息结构,设计得到椭圆族金属条带构成的原型全息天线。接着,针对原型全息天线尺寸较大的问题,实现了其小型化设计。核心思想是提高全息天线的有效辐射口径,通过对全息结构能量分布的分析,定性地确定小型化方法——去除冗余的、无效的散射区域,并采取理想磁导体(PMC)截断的方式引入合适的阵因子,提高天线增益;然后利用PMC截断与适当位置处的自然截断的等效关系,进一步简化结构,降低成本。最后,对原型全息天线和其小型化天线进行加工制版、实验测试,实验证明,实测结果与仿真结果吻合良好。最终,不仅大幅降低了天线面积,而且,将天线增益提高3.61dB(实测)。然后,阐述了全息天线在天线测试方面的新应用,针对传统的紧缩测试场采用的反射面曲面表面加工精度高、成本较高的问题,提出了用平面的全息结构来代替弯曲的反射面,有效降低了紧缩场测试对校准单元的表面精度的要求;同时,平面结构更易高精度地制造,并降低了成本,产生了良好的静区。最后,为了避免上述全息紧缩场天线系统的馈源对准、固定问题,设计完成了平面化或者共形化的全息紧缩测试场系统,先从平面化全息天线的实现出发,将其馈源天线作为本设计的馈源天线的阵列单元——平面印刷偶极子,全息结构的构建方式与前述相同,这样,馈源天线与全息结构被印制在同一块介质板表面,这种结构易集成,不存在机械地进行馈源对准和固定,且很大程度上降低了紧缩场系统占据的空间,更重要的,产生了基本满足要求的静区,静区场的幅度和相位变化均符合紧缩测试场静区的变化特性,进一步优化,能够得到更优良的静区特性。
[Abstract]:The research of holographic antenna has become a hot topic. The concept of holography comes from optics, but it has a larger application prospect in microwave frequency band. Its structure is simple, the feed form is flexible, and the new concept-interference is used to construct the scatterler structure. In turn, a beam with the radiation characteristics of the target is generated. In this paper, the research background of holography is determined from the status quo of holography research and the problems existing in the present research, and the main work and research ideas of this paper are determined through analysis. According to the core work to determine our research methods and needs of the auxiliary tools, the core work mainly includes the following aspects. Firstly, based on the structure and theory of the holographic antenna, the interference field of the radiation characteristics between the feed antenna and the target is calculated and the interference pattern is obtained. A prototype holographic antenna composed of elliptical metal strip is designed. Then, the miniaturization design of the prototype holographic antenna is realized. The core idea is to improve the effective radiation aperture of the holographic antenna. By analyzing the energy distribution of the holographic structure, the miniaturization method is determined qualitatively to remove the redundant and invalid scattering region. The ideal magnetic conductor PMC truncation is used to introduce the appropriate array factor to increase the antenna gain, and the equivalent relationship between the PMC truncation and the natural truncation at the appropriate position is used to further simplify the structure and reduce the cost. Finally, the prototype holographic antenna and its miniaturized antenna are processed and plate-making. The experimental results show that the measured results are in good agreement with the simulation results. Finally, not only the antenna area is greatly reduced, but also the antenna gain is increased by 3.61 dB. Then, the new application of holographic antenna in antenna testing is described. Aiming at the problems of high precision and high cost of surface machining of reflector surface used in the traditional compact test field, a plane holographic structure is proposed to replace the curved reflector. At the same time, the plane structure is easier to be manufactured with high precision, and the cost is reduced, and a good static zone is produced. Finally, in order to avoid the feed alignment and fixed problem of the holographic compact field antenna system mentioned above, a plane or conformal holographic contraction test field system is designed and completed. The first step is to realize the plane holographic antenna. The feed antenna is used as the array element of the feed antenna of the design, the planar printed dipole, and the holographic structure is constructed in the same way as mentioned above, so that the feed antenna and the holographic structure are printed on the surface of the same dielectric plate. This structure is easy to integrate, there is no mechanical feed alignment and fixation, and to a large extent reduces the space occupied by the compact field system, and, more importantly, produces a static zone that basically meets the requirements. The variation of amplitude and phase of the static field accords with the variation of the static zone of the compression test field. Further optimization can obtain better static characteristics.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN820

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