基于紧耦合结构的天线阵列设计

发布时间：2018-02-25 18:34

本文关键词： 紧耦合阵列偶极子阵列宽带巴伦阻抗变换　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：紧耦合天线阵是近来引人关注的研究热点。与传统的天线阵列设计过程中将天线单元之间的互耦效应看做不利因素不同,紧耦合天线阵利用天线单元之间的互耦效应来展宽带宽,实现宽带化的同时可以降低剖面高度。然而在实际的工程应用中,有限阵列的截断效应和单元的馈电巴伦结构问题限制了紧耦合天线阵取得更宽的阻抗带宽。本文针对以上两个问题,对紧耦合天线阵进行了相关研究。论文的主要工作包括以下几个部分:1.研究了截断效应对有限规模,尤其是单元数目较少的紧耦合天线阵的影响。首先通过对现有结构的研究,设计了振子臂末端具有重叠结构的双面印刷偶极子天线作为紧耦合天线阵的单元,同时通过在阵列上方覆盖介质层使带宽进一步的展宽。然后利用有限阵列与半无限周期阵列相结合的方法,针对所设计的6?6规模的有限阵列,分析了截断效应对紧耦合天线阵的影响。结果表明E面截断时形成的截断效应主要影响有限阵列在低频端的阻抗特性。为了对截断效应造成的天线阵列的性能恶化进行补偿,研究了两种不同的端接方法。通过采用合适的端接方法,可以有效地改善阵列在低频端的阻抗失配,使得该阵列能够覆盖200MHz-500MHz的频率范围(VSWR小于3),且垂直剖面高度仅为0.15个最大工作波长。2.设计了应用于紧耦合偶极子天线阵的馈电巴伦结构。对采用不同结构的阻抗变换器的馈电巴伦结构进行了分析与建模仿真,发现在200MHz到500MHz内,由于低垂直剖面高度的要求,直接实现50欧姆到200欧姆的阻抗变换较为困难。于是,首先采用共面波导结构和5阶切比雪夫阻抗变换器把不平衡端的50欧姆端口阻抗渐变为平衡端的100欧姆端口阻抗。然后,利用平行双导线结构对相邻天线单元进行并联馈电,最终在0.11个最大工作波长的剖面高度内实现了50欧姆到200欧姆的阻抗变换。
[Abstract]:The tightly coupled antenna array is a hot research topic in recent years. It is different from the traditional antenna array design that the mutual coupling effect between antenna elements is regarded as a disadvantage factor. The tightly coupled antenna array uses the mutual coupling effect between the antenna elements to widen the bandwidth, which can reduce the height of the section while achieving broadband. However, in practical engineering applications, The truncation effect of finite array and the problem of element feeding Barron structure limit the wider impedance bandwidth of tightly coupled antenna array. The main work of this paper includes the following parts: 1. The effect of truncation on the finite scale, especially the compact coupled antenna array with a small number of units is studied. A double-sided printed dipole antenna with overlapping structure at the end of the oscillator arm is designed as the element of the tightly coupled antenna array. At the same time, the bandwidth is further widened by covering the dielectric layer over the array. Then, by combining the finite array with the semi-infinite periodic array, the proposed method is applied to the design of 6? A limited array of 6 sizes, The effect of truncation effect on tight coupled antenna array is analyzed. The results show that the truncation effect of E plane truncation mainly affects the impedance characteristics of finite array at low frequency. In order to compensate for the deterioration of antenna array performance caused by truncation effect, Two different termination methods are studied. The impedance mismatch of the array at the low frequency can be effectively improved by adopting the proper termination method. The array can cover the frequency range of 200MHz-500MHz and the vertical section height is only 0.15 maximum working wavelength .2.The feed Barron structure for tightly coupled dipole antenna array is designed. The impedance of different structures is applied to the antenna array. The feed Barron structure of the converter is analyzed and simulated. It is found that in the range of 200MHz to 500MHz, it is difficult to realize the impedance conversion from 50 ohm to 200 ohms directly due to the requirement of low vertical profile height. Firstly, the coplanar waveguide structure and the 5th order Chebyshev impedance converter are used to convert the impedance of 50 ohms at the unbalanced end to 100 ohms at the balance end, and then parallel feeding of the adjacent antenna elements is carried out using the parallel double conductor structure. Finally, the impedance transformation from 50 ohm to 200 ohms is realized at the height of 0.11 maximum operating wavelengths.
【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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