平面聚焦天线低副焦斑和多焦斑的研究

发布时间：2018-11-16 07:27

【摘要】：天线一般工作在其辐射远场区域。对于某些特定场合,要求天线辐射的能量聚集在其近场区域的某一特定点上,这就需要近场聚焦天线。针对近场聚焦天线的研究已经持续了很长时间。在特定区域具有高能量密度的近场聚焦天线不仅可以用于提高医学与工业检测系统的探测和成像能力,还能用于门禁系统、微波无线输能系统、射频识别系统以及微波无线电系统等方面,具有广泛的应用前景和研究价值。不同应用场合对近场聚焦天线的需求也不相同。在微波热疗应用中希望利用最大功率加热癌组织,而不希望其对邻近健康组织产生危害;在非接触式微波感应中并不希望在焦点旁边有较高副瓣影响其准确性。因此,对近场聚焦天线实现低副瓣设计是降低副焦瓣影响的有效方法。当近场聚焦天线用于大面积检测时,可以通过需要焦斑扫描来扩大覆盖或提高位置定位精度。本文针对近场聚焦阵列天线相关问题展开研究,具体体现在:首先,在分析平面天线近场聚焦原理基础上,结合基片集成波导与金属圆波导实现了电磁波的近场聚焦。通过对基片集成波导近场聚焦天线的子部件进行分析,并对天线焦距与焦斑特性进行了讨论,最终对Ka频段基片集成波导近场聚焦天线进行设计、加工与实测。在此基础上,进一步研究近场聚焦天线的副瓣抑制问题。通过阐述近场区域低副焦瓣与圆极化的生成原理,即利用基片集成缝隙天线通过多元法实现圆极化,基于基片集成波导功分网络通过泰勒分布赋形实现所需近场副瓣电平,最终对K波段低副焦瓣双圆极化近场聚焦天线进行设计、加工与测试。最后,结合改进的基片集成波导罗特曼透镜与基片集成缝隙天线缝隙阵列天线,实现了Ka波段多焦斑天线。为了将基片集成罗特曼透镜作为聚焦波束形成网络,对传统罗特曼透镜的相移网络进行修改以满足波束聚焦和扫描的要求。当从不同的输入端口激发时,焦点可实现横向扫描。最终对Ka波段基片集成改进罗特曼透镜多焦斑近场聚焦天线进行设计、加工与测试。
[Abstract]:Antennas generally work in the far-field region of their radiation. For some special occasions, the energy of antenna radiation is required to gather at a certain point in its near-field region, which requires the near-field focusing antenna. The research on the near-field focusing antenna has been going on for a long time. Near-field focusing antennas with high energy density in specific areas can be used not only to improve the detection and imaging capabilities of medical and industrial detection systems, but also to use in access control systems and microwave wireless energy transmission systems. Radio frequency identification system and microwave radio system have a wide application prospect and research value. The requirements of near-field focusing antenna are different in different applications. In the application of microwave hyperthermia, it is desirable to use the maximum power to heat the cancer tissue without harming the adjacent healthy tissue, and in the non-contact microwave induction, it is not desired to have a higher sidelobe next to the focus to affect the accuracy of the cancer tissue. Therefore, the design of low sidelobe for near-field focusing antenna is an effective method to reduce the influence of the sidelobe. When the near field focusing antenna is used for large area detection, the focal spot scanning can be used to expand the coverage or improve the positioning accuracy. In this paper, the related problems of near-field focusing array antenna are studied. Firstly, based on the analysis of the near-field focusing principle of planar antenna, the near-field focusing of electromagnetic wave is realized by combining the substrate integrated waveguide with the metal circular waveguide. Based on the analysis of the sub-components of the near-field focusing antenna of the substrate integrated waveguide, the focal length and focal spot characteristics of the antenna are discussed. Finally, the near-field focusing antenna of the substrate integrated waveguide in the Ka band is designed, machined and measured. On this basis, the sidelobe suppression problem of near-field focusing antenna is further studied. The generation principle of low focus lobe and circular polarization in near field region is described, that is, the circular polarization is realized by using substrate integrated slot antenna through multivariate method, and the required near field sidelobe level is realized by Taylor distribution based on substrates integrated waveguide power division network. At last, the design, fabrication and test of K band low-petal dual-circular polarized near-field focusing antenna are carried out. Finally, the Ka band multi-focal spot antenna is realized by combining the improved integrated waveguide Rottmann lens with the slot array antenna of the substrate integrated slot antenna. In order to integrate the substrate into the Rottmann lens as a focusing beamforming network, the phase shift network of the traditional Rottmann lens was modified to meet the requirements of beam focusing and scanning. When fired from different input ports, the focus can be scanned horizontally. Finally, the design, fabrication and test of the Ka band substrate integrated and improved Rottmann lens near field focusing antenna with multiple focal spots are carried out.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN820

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