多频带多极化微带贴片天线研究

发布时间：2018-11-04 12:49

【摘要】：天线作为无线通信系统的关键部件,一直都是研究热点,尤其是微带贴片天线,因其具有易共形、低剖面、易加工、易与有源器件集成等优点而受到关注,已广泛应用于飞行器以及移动通信设备上。随着无线通信技术和多媒体技术的快速发展,对于能工作在多频带的天线的需求日渐增长,而不同频段往往需要不同的极化方式,如在GPS频段大多采用圆极化方式,在Wi-Fi、GSM频段则大多采用线极化方式,因此设计既满足多频段要求同时又满足不同频段极化方式不同要求的天线成为天线领域的一个难题。本文首先分析了单极天线和微带贴片天线在无人机上的工作性能,然后研究了多频带线极化微带贴片天线的实现方式,在此基础上进一步深入研究了实现多频带多极化微带贴片天线的不同方法及其小型化技术。本文的主要研究工作和创新点如下：1.以无人机通信为应用背景,分析了单极天线和微带贴片天线在无人机上的工作性能。首先从工作在Wi-Fi频段的单极天线着手,进行了单极天线与无人机机体的一体化建模,对比了单极天线在自由空间和在无人机上的特性差别；其次对工作在Wi-Fi频段的微带贴片天线与无人机机体进行了一体化建模,分析了贴片天线在自由空间和在无人机上的工作性能差别；进一步对比了单极天线和微带贴片天线在无人机上的性能差异,分析了存在的问题。2.提出了一种利用缝隙加载技术实现贴片天线多频带辐射的方法,该方法利用贴片天线的基模产生低频段辐射,利用加载的弧形缝隙产生高频段辐射。为了增大阻抗带宽,采用了电容贴片馈电和双层介质结构。采用该方法设计了工作于GPS L1频段和Wi-Fi 2.4 GHz频段的双频带线极化天线、以及工作于GPS L1频段和Wi-Fi的2.4/5.5 GHz频段的三频带线极化天线。3.提出了一种双端口馈电的缝隙加载多频带多极化贴片天线结构,该结构利用双端口馈电实现了贴片上两个正交方向的工作模式,并且相位差约为90°,产生右旋圆极化,工作在GPS L1频段；同时利用加载缝隙引入了Wi-Fi 2.4 GHz的线极化频段。该天线能够满足GPS L1和Wi-Fi 2.4 GHz的带宽要求,并能保证两个频段远场方向图的一致性。4.提出了一种单端口馈电的L型缝隙加载实现贴片天线双频带多极化的方法,并设计了一种工作在1.575 GHz频段以及2.4 GHz频段的微带贴片天线,在1.575 GHz频段为左旋圆极化,在2.4 GHz频段为线极化。为满足GPS L1频段的右旋圆极化需求,进一步将上述左旋圆极化天线的辐射贴片进行了垂直镜像,实现了在GPS L1频段的右旋圆极化辐射。这两种天线具有馈电简单、方便加工、成本低廉、易于共形等优点。5.提出了一种单端口馈电的多频带多极化天线的小型化方法,利用高介电常数的介质材料,在保证厚度基本不变的情况下,将天线的尺寸减小了40%(相比于前边提到的天线)。该天线采用了三层介质结构,工作在低频段的辐射贴片在中层介质的上部,利用馈电贴片和辐射贴片之间的缝隙耦合馈电；工作在高频段的辐射贴片在最顶层介质上部,利用电容贴片馈电。该结构上层贴片和下层贴片分别独立地对各自的工作频段辐射有决定性贡献,该天线具有谐振频带易于调节的优点。
[Abstract]:As the key component of wireless communication system, the antenna has always been a hot spot, especially microstrip patch antenna, which has been widely used in aircraft and mobile communication equipment because of its advantages such as easy co-shape, low profile, easy processing, easy integration with active devices and so on. with the rapid development of wireless communication technology and multimedia technology, different polarization modes are required for different frequency bands, Therefore, the design not only meets the requirements of multi-band requirements, but also meets different requirements of different frequency band polarization modes, and becomes a difficult problem in the antenna field. In this paper, the working performance of monopole antenna and microstrip patch antenna on UAVs is analyzed first, then the realization mode of multi-band polarized microstrip patch antenna is studied. On this basis, the different methods of realizing multi-band multi-polarization microstrip patch antenna and its miniaturization technology are further studied. The main research and innovation points in this paper are as follows: 1. The operating performance of monopole antenna and microstrip patch antenna on UAVs is analyzed with UAV communication as its application background. Firstly, from the monopole antenna operating in Wi-Fi frequency band, the integrated modeling of monopole antenna and unmanned aerial vehicle body is conducted, and the difference between monopole antenna in free space and unmanned aerial vehicle is compared. secondly, the integrated modeling of the microstrip patch antenna and the unmanned aerial vehicle body working in the Wi-Fi frequency band is carried out, the working performance difference between the patch antenna in the free space and the unmanned aerial vehicle is analyzed, the performance difference of the monopole antenna and the microstrip patch antenna on the unmanned aerial vehicle is further compared, the problem of existence is analyzed. A method for realizing multi-band radiation of patch antenna by utilizing slot loading technique is proposed. The method utilizes the base mode of patch antenna to generate low-frequency band radiation, and uses the loaded arc-shaped gap to generate high-frequency band radiation. In order to increase the impedance bandwidth, a capacitive patch feed and a double dielectric structure are used. The dual-band polarized antenna operating in the GPS L1 band and Wi-Fi 2.4GHz band is designed, and the three-band linear polarized antenna operating in the 2. 4/ 5. 5GHz band of the GPS L1 band and the Wi-Fi is designed. A multi-band multi-polarization patch antenna structure with double-port feeding is proposed. The structure utilizes dual-port feed to realize the working modes of two orthogonal directions on the patch, and the phase difference is about 90 掳, thus generating right-hand circular polarization and working in the GPS L1 frequency band. At the same time, the polarization band of Wi-Fi 2.4 GHz is introduced by using the loading slot. The antenna can meet the bandwidth requirement of GPS L1 and Wi-Fi 2.4GHz, and can guarantee the consistency of the far field direction diagram of two frequency bands. This paper presents a method for realizing dual-band multi-polarization of patch antenna with single-port-fed L-shaped slot loading, and designs a microstrip patch antenna operating in 1. 575 GHz band and 2.4GHz frequency band, which is left-handed circularly polarized in 1.575GHz band and linearly polarized in 2.4GHz band. in order to meet the right-hand circular polarization requirement of the GPS L1 frequency band, the radiation patch of the left-hand circularly polarized antenna is further vertically mirror, so that the right-hand circularly polarized radiation in the GPS L1 frequency band is realized. The two antennas have the advantages of simple feeding, convenient processing, low cost, easy co-formation and the like. A method for miniaturization of multi-band multi-polarization antenna with single-port feeding is proposed. Using dielectric material with high dielectric constant, the size of the antenna is reduced by 40% (compared with the antenna mentioned above). The antenna adopts a three-layer dielectric structure, the radiation patch working in the low-frequency section is arranged at the upper part of the middle-layer medium, and is coupled and fed by a gap between the feeding patch and the radiating patch; and the radiating patch working in the high-frequency band is fed with the capacitive patch at the upper part of the top-layer medium. The upper layer patch and the lower layer patch of the structure independently contribute to the respective working frequency band radiation, and the antenna has the advantages of easy adjustment of the resonance frequency band.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN820

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