方向图可重构天线及其阵列研究

发布时间：2019-04-02 09:49

【摘要】：传统的相控阵天线由于受到阵元间互耦以及天线单元方向图辐射范围有限两个方面的限制,其阵列波束扫描范围较窄,远远达不到现代科技应用的需要。方向图可重构天线由于具备辐射波束可调的特性受到国内外研究人员的青睐,并成为解决相控阵大角度扫描的一种十分有效的方法。本论文对方向图可重构天线单元及其在相控阵中的应用进行研究,主要内容包括:第一章概述了方向图可重构天线及其阵列的研究背景和意义、国内外研究历史与现状,并说明了本文的主要工作。第二章介绍了方向图可重构天线及其相控阵的基本原理,包括微波开关、微带天线、八木天线及阵列天线的相关理论,并介绍了采用有源单元方向图方法对线性相控阵进行方向图综合。第三章提出了一种变容二极管加载的方向图可重构微带八木天线单元。两个寄生振子上分别加载两个变容二极管,通过调节变容二极管的容抗值,寄生振子可以成为反射器或者引向器,从而微带八木天线可实现方向图重构。基于单振子加载模型讨论了振子电抗随所加载变容二极管容抗值的变化情况,得到了使微带八木天线的寄生振子成为反射器或者引向器的容抗值的取值范围,并详细讨论了微带八木天线在H面的辐射方向图与加载容抗值之间的变化关系。第四章将变容二极管加载的方向图可重构微带八木天线作为阵列单元,构成了方向图可重构微带八木天线阵列。讨论了阵元间距以及变容二极管的容抗值对阵列单元的反射系数以及有源单元方向图的影响。加工并测试了一个五单元线性阵列的扫描方向图,测试结果表明,阵列方向图可实现从 70°到+70°的扫描,且增益波动小于2 dB。与传统相控阵相比,本文提出的方向图可重构微带八木天线阵列实现了相控阵的大角度扫描、低增益波动特性。第五章对方向图可重构缝隙阵列进行初步研究,实现了从 60°到+60°的阵列扫描范围,获得了垂直极化的大角度扫描方向图。与水平极化的阵列天线相比,该方向图可重构缝隙阵列在地平面传播时可获得更小的衰减。第六章总结全文工作,提出改进方向。
[Abstract]:Due to the limitation of mutual coupling between array elements and the limited radiation range of antenna element pattern, the array beam scanning range of traditional phased array antenna is very narrow, which is far from the requirement of modern science and technology application. The pattern reconfigurable antenna has been favored by researchers at home and abroad because of its adjustable radiation beam, and it has become a very effective method to solve the large angle scanning of phased array. The main contents of this thesis are as follows: in chapter 1, the background and significance of the research on directional reconfigurable antenna and its array are summarized, and the research history and present situation at home and abroad are also discussed. The main work of this paper is explained. In the second chapter, the basic principles of the pattern reconfigurable antenna and its phased array are introduced, including the theory of microwave switch, microstrip antenna, Uagi antenna and array antenna. The pattern synthesis of linear phased array using active cell pattern method is also introduced in this paper. In chapter 3, a reconfigurable microstrip octree antenna element loaded with varactor diode is proposed. Two varactor diodes are loaded on the two parasitic oscillators respectively. By adjusting the capacitance value of the varactor diodes, the parasitic oscillator can be used as a reflector or a guide, thus the microstrip octree antenna can be used to reconstruct the pattern. Based on the loading model of a single oscillator, the variation of the reactance of the oscillator with the capacitance value of the loaded variable capacitance diode is discussed. The range of the capacitance value of the parasitic oscillator of the microstrip Uagi antenna as a reflector or a guide is obtained, which makes the parasitic oscillator of the microstrip Uagi antenna become a reflector or a deflector. The relationship between the radiation pattern of the microstrip Uagi antenna on the H plane and the load capacity reactance is discussed in detail. In chapter 4, the pattern reconfigurable microstrip octree antenna loaded by varactor diode is used as the array element, and the pattern reconfigurable microstrip octree antenna array is constructed. The effects of array element spacing and capacitive value of varactor diode on the reflection coefficient of array element and the pattern of active cell are discussed. The scanning pattern of a five-unit linear array is processed and tested. The test results show that the array pattern can be scanned from 70 掳to 70 掳, and the gain fluctuation is less than 2 dB.. Compared with the traditional phased array, the proposed pattern reconfigurable microstrip octree antenna array realizes the large angle scanning and low gain fluctuation characteristics of the phased array. In chapter 5, the scan range from 60 掳to 60 掳is realized, and the vertical polarization scanning pattern with large angle is obtained through a preliminary study on the reconfigurable slot array of the square pattern. Compared with the horizontally polarized array antenna, the reconfigurable slot array can obtain less attenuation when it propagates in the ground plane. The sixth chapter summarizes the full text of the work, puts forward the direction of improvement.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN820

【相似文献】