用于MIMO系统的基站天线研究与设计

发布时间：2018-03-16 17:45

本文选题：MIMO　切入点：基站天线　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】：平板电脑、智能手机、掌上游戏机等移动设备的蓬勃发展以及当前移动通信用户的数量剧增,为无线通信的质量和数据传输的速度提出了巨大的挑战。基站天线在通信系统中扮演着至关重要的角色,高性能的基站天线可以提供更优的通信质量与更快的通信速率。MIMO(multiple input multiple output多输入多输出)技术在提高通信速度和信道容量方面有着独特的优势,其与基站天线的结合为当前不断增加的高速通信需求提供了可行方案。因此,设计应用于MIMO基站通信的高性能天线单元与阵列变得非常有必要。本文首先介绍了基站天线的基本概念与实际应用中的相关要求,在此基础上进一步阐述了MIMO技术与基站天线结合的可行性。本文在磁电偶极子天线的基础上设计出了满足项目要求的高增益宽带12单元MIMO基站天线阵列,完成了天线实物的加工与测试,达到了项目关于带宽、增益、阵元数目、最大功率容量的要求。本文对磁电偶极子天线进行了较为深入的分析,从工作原理、电流分布等方面入手,并在此基础上,设计出了具有陷波特性的MIMO基站天线阵列,实现了大范围陷波频带可调的高性能MIMO天线系统设计,加工的天线实物测量结果与仿真结果吻合良好,实现了很好的工作特性。其次,本文还利用双U型槽结构设计出了工作于WLAN与WIMAX的双带基站天线单元。除了在所需工作频段内具有很好的定向与高增益特性,通过调节不同U型结构的尺寸,还可以实现不同频段的应用需求。其频带单独可调性也为其应用于MIMO基站系统提供了很大的设计灵活性,其高增益与定向特性为其应用于远距离基站通信提供了一种选择。不得不提的是,该天线在高频处的方向图不稳定,这可能会导致一些对通信质量要求高的区域出现盲区进而限制其应用。分析其原因可知由于大小U型槽单独控制对应的工作频段,而在高频工作时,小U型槽的遮挡效应导致了高频方向图不稳定的出现。最后,针对上述提到的高频处方向图凹陷问题,本文采用Sierpinski分形结构代替U型水平贴片,利用分形结构的多频特性与自相似性设计出了可工作于WLAN 2.4GHz和5.2GHz的双频天线。并在此基础上设计出了一款双带双极化天线,测量结果基本与仿真结果相吻合,该天线利用双极化特性在有限的空间内可实现更大的通信容量,满足当前MIMO基站天线的大容量、高质量通信要求。
[Abstract]:Mobile devices, such as tablets, smartphones, handheld consoles, are booming and the number of mobile users is growing dramatically. It poses a great challenge to the quality of wireless communication and the speed of data transmission. The base station antenna plays an important role in the communication system. The high performance base station antenna can provide better communication quality and faster communication rate. Mimo multiple input multiple output multiple input multiple output (MIMO) technology has unique advantages in improving communication speed and channel capacity. The combination of the base station antenna and the base station antenna provides a feasible solution for the increasing demand for high-speed communication. It is necessary to design high performance antenna units and arrays for MIMO base station communication. Firstly, this paper introduces the basic concept of base station antenna and the related requirements in practical application. On this basis, the feasibility of combining MIMO technology with base station antenna is further expounded. Based on the magnetoelectric dipole antenna, a high gain broadband 12 unit MIMO base station antenna array is designed to meet the requirements of the project. The processing and testing of the antenna are completed, and the requirements of the project on bandwidth, gain, number of array elements and maximum power capacity are achieved. In this paper, the magnetoelectric dipole antenna is analyzed in depth, and the working principle is discussed. Based on the current distribution, a MIMO base station antenna array with notch characteristics is designed, and the high performance MIMO antenna system with adjustable notch frequency band is designed. The measured results of the processed antenna are in good agreement with the simulation results, and good working characteristics are achieved. Secondly, The dual band base station antenna unit working in WLAN and WIMAX is also designed by using the double U groove structure. In addition to having good directional and high gain characteristics in the required operating frequency band, the size of different U-shaped structures is adjusted. It can also meet the application requirements of different frequency bands, and its frequency band can be adjusted separately, which also provides great design flexibility for its application in MIMO base station system. Its high gain and directional characteristics provide a choice for its application in remote base station communication. It must be noted that the pattern of the antenna is unstable at high frequency. This may lead to blind areas in some areas that require high communication quality, and thus limit their application. Analysis of the reasons shows that because the size of the U groove controls the corresponding operating frequency band separately, while working at high frequency, The blocking effect of the small U groove leads to the instability of the high frequency pattern. Finally, in order to solve the problem mentioned above, the Sierpinski fractal structure is used to replace the U type horizontal patch. Based on the multi-frequency characteristic and self-similarity of fractal structure, a dual-frequency antenna which can work at WLAN 2.4GHz and 5.2GHz is designed. On this basis, a dual-band dual-polarization antenna is designed. The measured results are in good agreement with the simulation results. The antenna can achieve a larger communication capacity in a limited space by using the dual polarization characteristic, which can meet the requirements of large capacity and high quality communication of the current MIMO base station antenna.
【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;TN919.3

【参考文献】