大型平面阵列方向图综合研究

发布时间：2018-03-11 02:31

本文选题：大型平面阵列　切入点：方向图综合　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】：由于科学技术的快速发展,无线传输作为卫星通信、地面微波接力和各种军民雷达信息的传递方式,扮演了愈来愈重要的角色。天线是辐射和接收电磁波的一种技术装置,其特性可以直接影响到无线系统的工作性能。因此,在无线系统中设计出满足系统要求的天线设备具有举足轻重的作用。随着无线通信技术的迅猛发展和广泛应用,对天线性能提出了更高的要求。高性能的天线不仅可以放宽对系统的要求,并且能够改善整个系统的性能。不仅要求天线具备高增益、宽频带范围内的全向、扇形以及赋形波束等技术特点,而且要求天线具备电尺寸小、重量轻、造价低、结构简单等物理优点。然而,单一天线单元通常无法完全满足这些苛刻的要求,最简单且行之有效的方法就是对天线单元进行排列组合构成阵列。因此,寻求高效、简单且稳定的方向图综合算法一直是天线领域的焦点。大型平面阵列由于具有较宽的方位和俯仰扫描能力、较高的增益以及易于实现的三维波束赋形,从而得到了广泛应用。本文正是结合相关研究项目,对大型平面阵列方向图的综合展开了相关研究工作,可以分为以下三个部分:第一,研究了大型周期平面阵列的快速方向图综合方法。首先建立阵列激励与阵列阵因子的傅里叶变换关系;其次应用基于快速傅里叶变换的交替投影算法对阵列进行方向图综合。针对传统交替投影算法收敛速度慢的缺点,本文提出两种改进交替投影算子,分别对具有周期性排布特点的矩形栅格阵列和任意三角栅格阵列进行快速方向图综合。具体的仿真计算,验证了改进投影算子收敛速度快,计算时间短的优势。第二,研究了大型非周期平面阵列的快速方向图综合方法。针对非周期阵列激励与阵列阵因子之间的非周期傅里叶变换关系,提出一种快速综合非周期阵列方向图的方法。其基本思想是,首先在非周期阵列中内插虚拟单元构成虚拟周期阵列,然后利用基于快速傅里叶变换的交替投影算法对虚拟周期阵列进行方向图综合,最后通过周期阵列与非周期阵列的矩阵变换关系,得到相应的非周期阵列阵元激励。通过仿真计算,虚拟周期阵列的方向图与实际非周期阵列的方向图几乎完全吻合,验证了内插思想的可行性与正确性。第三,对时间调制阵列进行了理论研究与阵列方向图综合应用。通过在阵列设计中增加时间维,减小了阵列激励幅度的动态范围,从而降低了馈电网络的设计复杂度。
[Abstract]:With the rapid development of science and technology, wireless transmission plays a more and more important role as satellite communication, ground microwave relay and various military and civilian radar information transmission methods. Antenna is a technical device for radiating and receiving electromagnetic wave. Its characteristics can directly affect the performance of wireless system. Therefore, it is very important to design antenna equipment to meet the requirements of wireless system. With the rapid development and wide application of wireless communication technology, The high performance antenna can not only relax the requirements of the system, but also improve the performance of the whole system. The technical characteristics of sector and shaped beam require the antenna to have the physical advantages of small electric size, light weight, low cost, simple structure, etc. However, the single antenna unit is usually unable to fully meet these harsh requirements. The simplest and most effective method is to arrange and combine the antenna elements to form an array. The simple and stable pattern synthesis algorithm has always been the focus of antenna field. Large plane arrays have wide azimuth and pitch scanning ability, high gain and easy to realize three-dimensional beamforming. Therefore, it has been widely used. In this paper, the research work on the synthesis of large plane array pattern is carried out, which can be divided into the following three parts: first, The fast pattern synthesis method for large periodic plane arrays is studied. Firstly, the Fourier transform relationship between array excitation and array factors is established. Secondly, an alternating projection algorithm based on fast Fourier transform is used to synthesize the pattern of the array. In view of the disadvantage of the traditional alternating projection algorithm, two improved alternating projection operators are proposed in this paper. The fast pattern synthesis of rectangular grid array and arbitrary triangular grid array with periodic arrangement is carried out respectively. The concrete simulation results show that the improved projection operator has the advantages of fast convergence and short calculation time. A fast pattern synthesis method for large aperiodic plane arrays is studied. The aperiodic Fourier transform relationship between aperiodic array excitations and array factors is studied. In this paper, a fast method of synthesizing aperiodic array pattern is presented. The basic idea is: firstly, virtual periodic array is constructed by interpolating virtual cell in aperiodic array. Then the pattern of the virtual periodic array is synthesized by the alternating projection algorithm based on the fast Fourier transform. Finally, the matrix transformation relationship between the periodic array and the aperiodic array is adopted. The simulation results show that the pattern of the virtual periodic array is almost identical with that of the actual aperiodic array, which verifies the feasibility and correctness of the interpolation idea. The theory of time-modulated array and the application of array pattern synthesis are studied. By adding time dimension to array design, the dynamic range of array excitation amplitude is reduced, and the design complexity of feed network is reduced.
【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】：TN820.12

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