本文選題：中心饋電 + 低交叉極化　； 參考：《華南理工大學》2014年碩士論文

【摘要】：隨著全球衛(wèi)星導航系統(tǒng)（Global Navigation Satellite System，簡稱GNSS）向多模融合、多系統(tǒng)并存以及高精度化方向發(fā)展，具有多頻、圓極化、極低背瓣以及極低交叉極化等特性的GNSS終端天線成為當前的研究熱點和難點。本文以高精度GNSS系統(tǒng)為背景，研究了低交叉極化、低背瓣的雙頻圓極化微帶天線：包括中心饋電雙頻圓極化微帶天線，基于多徑扼流圈的中心饋電天線和基于RIS結構的中心饋電天線。論文主要包括三方面研究工作： 1.研究了一種簡單新穎的中心饋電雙頻圓極化微帶天線。天線由中心饋電探針、開口方環(huán)縫隙、兩層帶有調(diào)諧枝節(jié)的層疊貼片以及折疊地板組成。饋電探針位于貼片中心位置，對貼片的輻射性能影響最小，從而實現(xiàn)低交叉極化；開口方環(huán)縫隙改變了貼片徑向電流分布，，使得寬闊正面輻射可能；兩層帶有調(diào)諧枝節(jié)的層疊貼片實現(xiàn)了雙頻圓極化輻射；折疊地板提高了低仰角增益且進一步抑制了交叉極化。仿真結果表明該天線獲取了雙頻工作頻帶、圓極化性能和極低的交叉極化，在整個上半空間主極化與交叉極化的極化比15dB。 2.研究了一種基于多徑扼流圈的中饋天線。天線由上面提出的中心饋電雙頻圓極化天線和三環(huán)多徑扼流圈組合而成。多徑扼流圈通過抑制中饋天線地板上的表面波傳播從而縮小天線的背瓣，仿真結果表明該天線在兩個工作頻段內(nèi)實現(xiàn)了圓極化，獲取了極低交叉極化和極低背瓣的輻射特性，天線的3-dB軸比波束寬度覆蓋整個上半空間，前后比達到25dB以上，非常適合應用于高精度船載衛(wèi)星導航與定位系統(tǒng)。 3.研究了一種基于純電抗性阻抗表面（Reactive Impedance Surface，簡稱RIS）結構的中饋天線。天線由55的RIS單元陣列和第一部分提出的中心饋電雙頻圓極化天線構成。RIS結構不僅可以有效地改善天線的前后比特性，拓寬低頻段的帶寬，而且極大地降低了天線的剖面高度。仿真結果表明基于RIS結構的中心饋電雙頻圓極化微帶天線具有極低交叉極化和極低背瓣水平，3-dB軸比波束寬度覆蓋整個上半空間，前后比達到24dB以上，該天線也非常適合應用于高精度船載衛(wèi)星導航與定位系統(tǒng)。
[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.

【學位授予單位】：華南理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN965.2

【共引文獻】

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1 吳浩;王靈敏;田小建;單江東;;基于高阻表面微波光子晶體的微帶天線設計[J];吉林大學學報(理學版);2014年03期

2 徐莎;王冬;秦奮;范植開;;同軸波導中二維金屬光子晶體的電磁特性[J];強激光與粒子束;2014年03期

3 范曉丹;單江東;;內(nèi)嵌結構光子晶體在F型微帶天線中的應用[J];微波學報;2014年02期

相關碩士學位論文 前1條

1 范曉丹;寬禁帶微波光子晶體及其在微帶天線中的研究與應用[D];吉林大學;2014年

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