终端共体MIMO天线

发布时间：2018-09-03 13:59

【摘要】：随着第三、四代移动通信网络的成熟与普及,移动终端设备得到快速的发展,天线作为终端设备接收无线信号的前端部件,也发生着巨大的变化,随着手机功能增多,金属机身流行,以及MIMO天线技术的应用,终端天线不仅要满足小型化、宽频化、多频带的技术要求,而且还要克服金属机身对天线辐射性能的恶化影响,设计具备多种功能的多天线(multi-antenna)系统。根据上述需求与挑战,本文提出了三款共用金属边框的终端MIMO天线设计方案。首先,本论文分析了终端天线发展以及国内外研究现状,总结了终端天线设计所面临的挑战,以及本论文的研究重点和创新之处。然后结合天线理论知识,对用于终端MIMO天线设计的常用天线形式、实现小型化、宽频带方法、MIMO天线性能衡量指标以及实现MIMO天线高隔离的常用方法进行归纳。其次,本论文提出一款共用金属边框的双WIFI天线,金属边框同时作为两天线的主要辐射结构,利用去耦结构提高天线单元之间的隔离度,随后对天线的S参数、辐射特性、MIMO分集特性进行测试。最后通过在单元天线1馈电端口设计匹配网络,有效增加天线单元1工作带宽,实现WIFI/GPS同时覆盖。再次,本论文提出一款共用金属边框的七频可重构MIMO天线。天线采用U形微带线耦合馈电方式,激励起由金属边框与地板构成的金属环,利用环天线多模谐振特点以及开关可重构技术,实现天线四种工作状态切换,最终覆盖七个通信频段。根据环天线电流分布特性,通过合理设计天线位置,实现MIMO天线在整个工作频带内具有较好的隔离度。文章从电流分布图、重要参数讨论对天线工作原理进行详细分析,最后通过加工测试,对天线的辐射特性与分集特性进行了评估。最后,本论文提出了一款用于完整金属边框终端的多天线系统,该天线系统既包含LTE七频天线又包含双频WIFI MIMO天线,三副天线共用完整金属边框作为天线结构进行辐射。LTE天线通用匹配网络对端口进行阻抗匹配,实现七个频段覆盖(GSM850/900/GSM1800/1900/UMTS2100/LTE2300/2500),WIFI天线采用被动可重构原理,实现2.4GHz与5.8GHz双频段覆盖。随后对天线的工作原理进行了详细分析,通过对天线模型加工测试,结合天线的仿真结果进行对比分析,最终得到工作带宽、隔离度、辐射效率、MIMO天线分集特性均满足设计要求共用金属边框的终端天线系统。
[Abstract]:With the maturity and popularity of the third and fourth generation mobile communication networks, mobile terminal equipment has been rapidly developed. As the front-end component of terminal equipment receiving wireless signals, antenna has also undergone tremendous changes. With the increase of mobile phone functions, the popularity of metal fuselage, and the application of MIMO antenna technology, the terminal antenna should not only meet the needs of miniaturization and widening. To overcome the deterioration of radiation performance caused by metal fuselage, a multi-antenna system with multiple functions is designed. According to the above requirements and challenges, three MIMO antenna design schemes with common metal frame are proposed in this paper. Firstly, the development of terminal antenna is analyzed. Then, combined with antenna theory knowledge, the common antenna forms used in terminal MIMO antenna design are realized, including miniaturization, broadband method, performance measurement index of MIMO antenna and high isolation of MIMO antenna. Secondly, a dual WIFI antenna with a common metal frame is proposed. The metal frame is used as the main radiation structure of the two antennas. The isolation between the antenna elements is improved by using the decoupling structure. Then the S parameters, radiation characteristics and MIMO diversity characteristics of the antenna are tested. Thirdly, a seven-band reconfigurable MIMO antenna with a common metal frame is proposed in this paper. The antenna is fed by a U-shaped microstrip line to excite a metal ring composed of a metal frame and a floor. The multi-mode resonance characteristics of the ring antenna are utilized. According to the current distribution characteristics of the ring antenna, the MIMO antenna has a good isolation degree in the whole working frequency band by designing the antenna position reasonably. This paper discusses the working principle of the antenna in detail from the current distribution diagram and the important parameters. Finally, the radiation and diversity characteristics of the antenna are evaluated by processing and testing. Finally, a multi-antenna system for the terminal with complete metal frame is proposed, which includes both LTE seven-band antenna and dual-band WIFI MIMO antenna. Line radiation. LTE antenna general matching network matches the impedance of the port to achieve seven band coverage (GSM850/900/GSM1800/1900/UMTS2100/LTE2300/2500). WIFI antenna uses passive reconfigurable principle to achieve 2.4 GHz and 5.8 GHz dual band coverage. Then the working principle of the antenna is analyzed in detail, and the antenna model is processed and tested. Comparing with the simulation results of the MIMO antenna, the bandwidth, isolation, radiation efficiency and diversity characteristics of the MIMO antenna can meet the design requirements of the terminal antenna system with a common metal frame.
【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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