功分移相馈电网络和圆极化定向微带天线技术研究

发布时间：2018-05-27 07:31

本文选题：圆极化天线 + 移相器　；参考：《北京邮电大学》2014年博士论文

【摘要】：随着我国北斗卫星导航系统(CNSS)和物联网应用相关产业规划的快速推进,相关新型电子系统对其信号收发部件——天线性能提出了更高要求；然而,目前的圆极化定向微带天线带宽扩展技术、双频技术、阵列天线技术均面临应用方面的技术难题。在此背景下,本论文主要面向CNSS和RFID系统应用,首先提出全新的弱耦合线加载枝节混合型宽带90度移相电路结构和设计方法；然后以宽带功分移相馈电网络研究为基础,先后提出并实现紧凑型宽带多馈电圆极化定向微带天线和双频圆极化定向RFID读写天线；最后,首次提出采用非对称耦合线功分器和非均匀旋转馈电网络设计圆极化定向阵列微带天线。论文的研究内容包括以下几个方面： 1.提出弱耦合线加载枝节混合型移相器。宽带90度移相器是非常重要的微波器件,高性能多馈电圆极化天线要求其具有较大的带宽、结构与设计简单、较好的设计可移植性、容易实现、加工成本低、便于安装和使用等优点；而目前的移相器结构很难同时满足以上需求。本论文提出采用弱耦合线分别加载开路枝节、阶跃阻抗谐振器、扇形枝节实现混合型宽带90度移相电路,利用奇偶模等效电路方法对所提出的电路结构进行理论分析并给出设计方法；通过电磁仿真与试验测试对所提出的微带单层移相电路结构及性能进行验证；结果表明所提出的宽带90度移相器分别实现带宽70.8%、105%和118%,性能满足圆极化天线设计需求。该部分研究工作是本论文的基础,为圆极化定向微带天线带宽扩展和双频技术的研究提供支撑。 2.面向CNSS双模终端应用,开展圆极化定向微带天线带宽扩展技术研究。具备GPS兼容和互操作功能的CNSS双模终端要求其天线频段能够覆盖频率范围：1.227-2.492GHz,即相对带宽大于68%；另外,便携式终端要求天线具有结构紧凑、质量轻等优点。本论文基于宽带90度移相器,设计了宽带功分移相馈电网络,同时提出采用四个旋转的部分扇形圆环耦合贴片实现宽带圆极化馈电结构,在此基础上提出并设计了紧凑型宽带双馈电圆极化定向微带天线和紧凑型宽带四馈电圆极化定向微带天线。对天线进行电磁仿真,然后加工组装天线实物,并进行试验测试。结果表明所提的宽带圆极化定向微带天线实现带宽72%,在带宽扩展技术研究上取得突破性进展,同时天线结构紧凑,体积约为现有最小天线体积的四分之一；天线性能满足CNSS双模终端应用需求。 3.面向双频RFID系统应用,开展圆极化定向微带天线双频技术研究。双频RFID系统要求圆极化定向读写天线实现单体双频工作,以降低系统成本、减小体积和质量,提升产品竞争力。由于目前的双频圆极化定向天线很难实现大频比的2.45/0.92GHz双频工作,因此相关的研究和报道很少,而且现有结构很难满足实际应用需求。本论文采用宽带功分移相馈电网络组合双频辐射结构的全新设计方案,开展0.920/2.45GHz双频圆极化定向RFID读写天线研究,提出并设计了高增益双频圆极化定向天线和紧凑双频圆极化定向天线。天线设置一个端口,在两个频段上具有相同的极化方向,该结构配置有益于双频RFID系统射频前端单体双频架构设计。通过电磁仿真和试验测试结果对比方法,对天线结构和性能进行验证。天线在两个频段上均具有满足应用需求的带宽、增益、轴比和辐射方向图。 4.基于非对称耦合线功分器和非均匀旋转馈电网络,开展圆极化旋转阵列天线技术研究。远距离高定向性RFID系统要求圆极化微带阵列天线不仅具有高增益,同时还必须具有较低的旁瓣电平、较高的前后比和较窄的波束宽度,确保以高准确率进行读写的同时,尽量降低对相邻区域以及后方区域范围的干扰。本论文提出采用非对称耦合线功分器和非均匀旋转馈电网络组合方案,开展旋转阵列天线技术研究,设计了2.45GHz圆极化16单元旋转定向微带共面阵列天线。以T形结功分器和均匀旋转馈电网络阵列天线技术作为参考,通过试验测试和性能对比方法验证所提出的阵列天线技术以及性能提升效果。结果表明阵列天线的圆极化带宽由8.2%增加为11.9%,带内回波损耗改善6dB以上,带内轴比降低0.9dB以上,天线的旁瓣和后向辐射性能得到有效改善。
[Abstract]:With the rapid advance of the related industrial planning related to the Beidou satellite navigation system (CNSS) and the Internet of things applications, the related new electronic systems have put forward higher requirements for the performance of their signal transceiver components, the antenna performance. However, the current circular polarization directional microstrip antenna bandwidth expansion technology, dual frequency technology and array antenna technology are all faced with applications. In this context, this paper is mainly oriented to the application of CNSS and RFID systems. First, we propose a new structure and design method for the weak coupled line loaded hybrid broadband 90 degree phase shift circuit. Then, based on the research of the broadband power shift phase feed network, the compact broadband and multi feed circular polarization directional microstrip is put forward and realized successively. Antenna and dual frequency circular polarization directional RFID read-write antenna. Finally, the design of circular polarized directional array microstrip antenna with asymmetric coupling line power divider and non-uniform rotating feed network is proposed for the first time. The research contents of this paper include the following aspects:
1. a weakly coupled line loaded branch type hybrid phase shifter is proposed.
Wide-band 90 degree phase shifter is a very important microwave device. High performance multi feed circular polarization antenna requires large bandwidth, simple structure and design, good design and portability, easy to implement, low machining cost, easy to install and use, and so on. We use the weak coupling line to load open branches, step impedance resonators and fan-shaped branches to realize the hybrid broadband 90 degree phase shift circuit. Using the parity mode equivalent circuit method, the proposed circuit structure is theoretically analyzed and the design method is given. Through electromagnetic simulation and test test, the proposed microstrip single-layer phase shift circuit structure is proposed. The results show that the proposed broadband 90 degree phase shifter realizes the bandwidth 70.8%, 105% and 118% respectively. The performance meets the design requirements of the circular polarized antenna. This part of the research work is the basis of this paper, which provides support for the research of the bandwidth expansion and dual frequency technology of the circular polarized directional microstrip antenna.
2. for CNSS dual mode terminal applications, we develop the technology of bandwidth expansion for circularly polarized microstrip antennas.
CNSS dual mode terminals with GPS compatibility and interoperability require that the antenna band can cover the frequency range: 1.227-2.492GHz, that is, the relative bandwidth is greater than 68%. In addition, the portable terminal requires the antenna to have the advantages of compact structure and light quality. Based on the broadband 90 degree phase shifter, a broadband power shift phase feed network is designed. A wide-band circular polarization feeding structure is realized by using four rotated sector circular ring coupling patches. On this basis, a compact broadband dual feed circular polarized directional microstrip antenna and a compact broadband four circular polarized directional microstrip antenna are proposed and designed. The electromagnetic imitation of the antenna is carried out and the antenna is fabricated and tested. The test results show that the bandwidth of the wideband circular polarization directional microstrip antenna is 72%. It has made a breakthrough in the research of bandwidth expansion technology. At the same time, the antenna structure is compact and the volume is about 1/4 of the existing minimum antenna volume. The antenna performance meets the needs of the CNSS dual mode terminal.
3. for dual frequency RFID system applications, the dual frequency technology of circularly polarized microstrip antennas is researched.
Dual frequency RFID system requires circular polarization directional read-write antenna to achieve single frequency dual frequency work, in order to reduce system cost, reduce volume and quality, improve product competitiveness. Because the current dual frequency circular polarization directional antenna is difficult to achieve 2.45/0.92GHz dual frequency work with large frequency ratio, so the related research and report are very few, and the existing structure is difficult to meet. In this paper, a new design scheme of dual frequency radiation structure of broadband power shift phase feed network is used in this paper. The research of 0.920/2.45GHz dual frequency circular polarization directional RFID reading and writing antenna is carried out. A high gain double frequency circular polarization directional antenna and compact dual frequency circular polarization directional antenna are proposed and designed. The antenna is set up at two. The frequency band has the same polarization direction. The configuration is beneficial to the design of the dual frequency structure of the RF front end of the dual frequency RFID system. The antenna structure and performance are verified by the electromagnetic simulation and experimental test results. The antenna has the bandwidth, the gain, the axis ratio and the radiation pattern on the two frequency bands.
4. based on asymmetric coupled power divider and non-uniform rotary feed network, circular polarization rotated array antenna technology is studied.
The long distance and high directional RFID system requires that the circularly polarized microstrip array antenna not only has high gain, but also has a lower sidelobe level, a higher back-back ratio and a narrower beam width to ensure a high accuracy rate for reading and writing, as well as to minimize interference to the adjacent area and the area of the rear area. This paper proposes to use this paper. An asymmetric coupled linear power divider and an inhomogeneous rotating feed network combination scheme and the research of rotating array antenna technology are carried out. The 2.45GHz circular polarization 16 unit rotation directional microstrip coplanar array antenna is designed. The T junction power divider and the uniform rotating feed network array antenna are taken as a reference, and the test test and performance comparison method are verified. The proposed array antenna technology and performance enhancement results show that the circular polarization bandwidth of the array antenna is increased from 8.2% to 11.9%, the echo loss in the band is improved by more than 6dB, the inner axis ratio is reduced by more than 0.9dB, and the sidelobe and backward radiation performance of the antenna can be effectively improved.
【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN822

【共引文献】