内置多频段手机天线的设计

发布时间：2018-04-23 01:19

本文选题：手机天线 + 多频段　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：随着蜂窝移动通信的迅速发展,手机可以工作在WIFI/WiMAX/3G等越来越多的无线网络中。因此,手机天线必须覆盖更多的工作频段,包括GSM/DCS/PCS/ISM等频段。由于手机日趋小型化、轻薄化的产品需求,硬件设计中为天线预留的空间非常有限,而手机天线又是无线通讯的关键环节,所以许多设计者都在致力于手机天线的小型化和多频带研发。论文针对低剖面内置多频段手机天线的设计和优化展开了研究工作。主要内容包括:1.总结了微带天线的馈电方式及微带天线分析中需注意的表面波效应。讨论了手机天线的方向图等主要特性参数和微带天线分析中常用的原理和方法,详细分析了几种经典的双频、三频PIFA天线以及单极天线在实际的手机设计应用中存在的性能优势与缺陷,并归纳了已经被提出的设计技巧和优化方案。2.针对手机天线要覆盖更多工作频段的通信需求和平面单极天线尺寸小、剖面低、容易在多频段工作等诸多优势,设计了两个内置宽频带单极手机天线。详细阐述了设计的思路与流程,并结合仿真软件进行多次调试、优化,讨论了天线设计中结构体各主要尺寸参数的变动对整体天线性能的影响。最后两个天线均实现了良好的阻抗带宽,可以覆盖GSM/DCS/PCS/UMTS等通讯频段,且其在所覆盖工作频段内呈现出较好的全向性,加之二者低剖面、易封装等特,适合在实际的手机设计中应用。3.详细阐述了阻抗匹配的基本原理,从理论上分析了匹配电路在手机天线设计中应用潜在的优缺点,讨论了利用匹配电路来优化天线性能过程中应遵循的设计准则。详细地介绍了利用CST(Computer Simulation Technology)microwave studio及ADS(Advanced Design System)软件联合仿真,进行天线的匹配电路设计的流程。通过对两个PIFA天线实例进行匹配电路设计,验证了匹配电路在天线性能优化中的优势与弊端,得出结论:匹配电路是手机天线设计中靠调节天线辐射体自身改变天线性能出现瓶颈时的一个新出路,在改变天线体自身无法再优化时,通过匹配电路的加载,可能会给天线性能带来很大的提升。但此种方案并非适用于所有的手机天线,不是所有的既定天线都能通过匹配电路的引入而得到理想的性能提升。匹配电路的选择与设计要综合考虑其给天线射频性能各方面带来的改变。
[Abstract]:With the rapid development of cellular mobile communication, mobile phones can work in more and more wireless networks such as WIFI/WiMAX/3G. Therefore, the mobile phone antenna must cover more working frequency bands, including GSM/DCS/PCS/ISM and so on. Due to the increasing miniaturization and thinning of mobile phones, the space reserved for antennas in hardware design is very limited, and the antenna of mobile phones is a key link in wireless communication. So many designers are working on the miniaturization of mobile phone antennas and multi-band R & D. In this paper, the design and optimization of low-profile multi-band mobile phone antenna are studied. The main contents include: 1. The feed mode of microstrip antenna and the surface wave effect in the analysis of microstrip antenna are summarized. This paper discusses the main characteristic parameters such as the pattern of antenna of mobile phone, the principle and method commonly used in the analysis of microstrip antenna, and analyzes in detail several kinds of classical dual-frequency. The advantages and disadvantages of three-frequency PIFA antenna and monopole antenna in the design and application of mobile phone are summarized. Aiming at the communication requirement of mobile phone antenna covering more working frequency bands and the advantages of small size of planar monopole antenna, low profile and easy to work in multi-frequency band, two built-in broadband monopole mobile phone antennas are designed. The idea and flow of the design are described in detail, and the simulation software is used to debug and optimize the antenna. The influence of the main dimension parameters of the structure on the performance of the whole antenna is discussed. The last two antennas have achieved good impedance bandwidth, which can cover GSM/DCS/PCS/UMTS and other communication frequency bands, and show good omnidirectional performance in the working band covered by them. In addition, the two antennas have low profile and are easy to encapsulate, etc. Suitable for the actual mobile phone design application. 3. The basic principle of impedance matching is described in detail, the potential advantages and disadvantages of matching circuit in antenna design of mobile phone are analyzed theoretically, and the design criteria to be followed in the process of optimizing antenna performance by using matching circuit are discussed. The flow chart of antenna matching circuit design using CST(Computer Simulation Technology)microwave studio and ADS(Advanced Design system software is introduced in detail. Through the design of matching circuit for two PIFA antenna examples, the advantages and disadvantages of matching circuit in antenna performance optimization are verified. The conclusion is that the matching circuit is a new way to change the antenna performance by adjusting the antenna radiator itself. When the antenna body itself can not be optimized, the matching circuit is loaded. It may bring a great improvement to the antenna performance. However, this scheme is not suitable for all mobile phone antennas, and not all the fixed antennas can be improved by the introduction of matching circuits. The selection and design of matching circuit should take into account the change of antenna RF performance.
【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】：TN828.6

【参考文献】