中心馈电双频圆极化微带天线研究

发布时间：2018-04-20 05:00

本文选题：中心馈电 + 低交叉极化　；参考：《华南理工大学》2014年硕士论文

【摘要】：随着全球卫星导航系统（Global Navigation Satellite System，简称GNSS）向多模融合、多系统并存以及高精度化方向发展，具有多频、圆极化、极低背瓣以及极低交叉极化等特性的GNSS终端天线成为当前的研究热点和难点。本文以高精度GNSS系统为背景，研究了低交叉极化、低背瓣的双频圆极化微带天线：包括中心馈电双频圆极化微带天线，基于多径扼流圈的中心馈电天线和基于RIS结构的中心馈电天线。论文主要包括三方面研究工作： 1.研究了一种简单新颖的中心馈电双频圆极化微带天线。天线由中心馈电探针、开口方环缝隙、两层带有调谐枝节的层叠贴片以及折叠地板组成。馈电探针位于贴片中心位置，对贴片的辐射性能影响最小，从而实现低交叉极化；开口方环缝隙改变了贴片径向电流分布，，使得宽阔正面辐射可能；两层带有调谐枝节的层叠贴片实现了双频圆极化辐射；折叠地板提高了低仰角增益且进一步抑制了交叉极化。仿真结果表明该天线获取了双频工作频带、圆极化性能和极低的交叉极化，在整个上半空间主极化与交叉极化的极化比15dB。 2.研究了一种基于多径扼流圈的中馈天线。天线由上面提出的中心馈电双频圆极化天线和三环多径扼流圈组合而成。多径扼流圈通过抑制中馈天线地板上的表面波传播从而缩小天线的背瓣，仿真结果表明该天线在两个工作频段内实现了圆极化，获取了极低交叉极化和极低背瓣的辐射特性，天线的3-dB轴比波束宽度覆盖整个上半空间，前后比达到25dB以上，非常适合应用于高精度船载卫星导航与定位系统。 3.研究了一种基于纯电抗性阻抗表面（Reactive Impedance Surface，简称RIS）结构的中馈天线。天线由55的RIS单元阵列和第一部分提出的中心馈电双频圆极化天线构成。RIS结构不仅可以有效地改善天线的前后比特性，拓宽低频段的带宽，而且极大地降低了天线的剖面高度。仿真结果表明基于RIS结构的中心馈电双频圆极化微带天线具有极低交叉极化和极低背瓣水平，3-dB轴比波束宽度覆盖整个上半空间，前后比达到24dB以上，该天线也非常适合应用于高精度船载卫星导航与定位系统。
[Abstract]:With the global satellite navigation system (Global Navigation Satellite System, abbreviated as GNSS) to multimode fusion, multi system coexistence and high precision direction, the GNSS terminal antenna with the characteristics of multi frequency, circular polarization, extremely low back flap and extremely low cross polarization has become the focus and difficulty of the current research. This paper uses high precision GNSS system as the back. A dual frequency circular polarized microstrip antenna with low cross polarization and low back petals is studied, including a central fed dual frequency circular polarized microstrip antenna, a central feed antenna based on a multipath choke and a central feed antenna based on the RIS structure. The thesis mainly includes three aspects of research:
1. a simple novel central feed dual frequency circular polarized microstrip antenna is studied. The antenna consists of a central feed probe, an open square ring slot, two layers of laminated patches with tunable branches and a folding floor. The feed probe is located at the center of the patch, which has the smallest effect on the radiation performance of the patch, so as to achieve low cross polarization; open square ring. The gap changes the distribution of the radial current of the patch, which makes the wide front radiation possible, and the two layers of laminated patches with tunable branches achieve double frequency circular polarization radiation. The folding floor improves the low elevation gain and further inhibits the cross polarization. The simulation results show that the antenna has a dual frequency band, circular polarization performance and extremely low polarization. Cross polarization, the polarization ratio of main polarization and cross polarization in the whole upper half space is 15dB.
2. a middle feed antenna based on a multipath choke is studied. The antenna is composed of a central fed dual frequency circular polarized antenna and a three ring multipath choke. The multipath choke reduces the antenna back by restraining the surface wave propagation on the medium feed antenna floor. The simulation results show that the antenna is implemented within the two working bands. With circular polarization, the radiation characteristics of extremely low cross polarization and extremely low back flap are obtained. The 3-dB axis of the antenna covers the whole upper half space than the beam width, and the front and back ratio of the antenna reaches more than 25dB. It is very suitable for high precision ship borne satellite navigation and positioning system.
3. a medium fed antenna based on the Reactive Impedance Surface (RIS) structure is studied. The antenna consists of 55 RIS unit arrays and a central fed dual frequency circular polarized antenna constructed by the first part, which can not only effectively improve the front and rear ratio characteristics of the antenna, widen the bandwidth of the low frequency segment, but also greatly improve the bandwidth of the low frequency segment. The simulation results show that the center fed dual frequency circular polarized microstrip antenna based on the RIS structure has extremely low cross polarization and very low back flap level, and the 3-dB axis ratio of the beam width covers the whole upper half space, the front and back ratio is above 24dB, and the antenna is also suitable for high precision ship borne satellite navigation and positioning. System.

【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN965.2

【共引文献】