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  本文關(guān)鍵詞：超表面圓極化天線　出處：《西南交通大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 圓極化 超表面 可加載 天線

【摘要】：隨著無線射頻技術(shù)的進(jìn)步,線極化天線已經(jīng)不適用于的特殊的設(shè)備要求。在遠(yuǎn)距離傳輸和抗干擾方面,圓極化天線有顯著的優(yōu)勢,圓極化波在雨雪中傳播衰減小,能穿透電離層,不受地球磁場產(chǎn)生的法拉第效應(yīng)(Faraday effect)影響。圓極化天線在無線通信領(lǐng)域應(yīng)用十分廣泛,比如全球定位系統(tǒng)(GPS,Global Position System),RFID閱讀器天線,電子不停車收費(fèi)(ETC,Electronic Toll Collection)系統(tǒng)天線。圓極化天線還被廣泛應(yīng)用在雷達(dá)監(jiān)測如云雨天氣監(jiān)測,日常林火監(jiān)測,海洋浮游生物監(jiān)測,水位檢測。本文先對天線的發(fā)展和超材料發(fā)展的國內(nèi)外現(xiàn)狀進(jìn)行介紹分析,還介紹了天線的基本參數(shù)和超材料的基本種類。再對微帶天線圓極化的不同技術(shù)路線進(jìn)行了介紹和分析,對單饋法圓極化天線的圓極化理論和腔模理論進(jìn)行了推導(dǎo),了解幾何微擾對簡并模產(chǎn)生的影響。接著,研究超表面產(chǎn)生圓極化的原理,設(shè)計了 5.8GHz縫隙天線和超表面。該超表面由4*4個周期性單元構(gòu)成,是在正方形的金屬表面進(jìn)行不規(guī)則開槽設(shè)計,其作用相當(dāng)于一個有圓極化功能的空間濾波器。加載超表面后可以把縫隙天線的線極化波轉(zhuǎn)變?yōu)閳A極化波,縫隙天線的阻抗帶寬(S11-10dB)為5.70-5.96GHz,加載超表面后圓極化波的軸比帶寬為5.03-6.22GHz,增益達(dá)6dB,該超表面還可以屏蔽工作頻帶外的電磁干擾。然而,由于該超表面面積尺寸太大,不適用于對小型化程度要求很高的閱讀器天線,所以對超表面的小型化方法進(jìn)行了研究。縫隙天線的結(jié)構(gòu)不變,超表面僅為以前超表面的1/16大小,但超表面的加載方式發(fā)生了改變,需要緊密貼合在微帶縫隙貼片天線背面。加載后的阻抗帶寬(S11-10dB)為5.65-6.05GHz,縫隙天線的原始軸比為60dB,加載一層超表面后軸比降為1OdB,加載兩層超表面后軸比最低降為5dB,加載三層超表面后軸比降為小于3dB,軸比帶寬為5.52-5.64GHz�？梢�,增加多層超表面后,天線的軸比帶寬可以得到擴(kuò)展,軸比也會降低。另外,因為FR4的厚度增加,等效介電常數(shù)增加,所以中心頻率有所降低。最后,研究了超表面旋轉(zhuǎn)角度對極化狀態(tài)的影響,縫隙天線的結(jié)構(gòu)不變,尺寸有所調(diào)整,阻抗帶寬(S11-10dB)為5.53-5.90GHz。當(dāng)超表面和縫隙天線對齊時,可以實現(xiàn)左旋圓極化,軸比帶寬為5.74-5.85GHz,當(dāng)超表面旋轉(zhuǎn)90度時,可以實現(xiàn)右旋圓極化,軸比帶寬為5.78-5.94GHz。圓極化天線的體積僅為25mm*25mm*4mm。極化狀態(tài)實現(xiàn)的原理是不同角度的超表面會產(chǎn)生不同的阻抗相位差,+90°的相位差和-90°相位差產(chǎn)生不同狀態(tài)的圓極化波,圓極化旋轉(zhuǎn)方向相反。
[Abstract]:With the development of wireless RF technology, special equipment of linear polarization antenna is not suitable to the requirements in the long-distance transmission and anti interference, circular polarization antenna has advantages, circular polarized wave attenuation propagation in the rain and snow, can penetrate the ionosphere, is not affected by the earth's magnetic field generated by the Faraday effect (Faraday effect) effect. Circular polarized antenna is widely used in the field of wireless communications, such as the global positioning system (GPS Global, Position System), RFID reader antenna, electronic toll collection (ETC, Electronic Toll Collection) system. The antenna circular polarized antenna is widely used in radar monitoring such as rain weather monitoring, daily monitoring of forest fire monitoring, marine plankton the water level detection, are introduced in this paper. First the development of antenna and metamaterial development situation at home and abroad, also introduces the basic parameters of the antenna and ultra basic materials Class. Then different technical route of microstrip antenna with circular polarization are introduced and analyzed, the single feed circularly polarized antenna with circular polarization theory and the theory of cavity are deduced, to understand the effect of geometrical perturbation for degenerate mode generated. Then, the principle of circular polarization study of ultra surface, design the 5.8GHz slot antenna and super surface. The super surface is composed of a 4*4 periodic unit is irregular slotted design on the metal surface of the square, which is equivalent to a circular polarization function of the spatial filter. Loading surface can get the slot antenna line polarization wave into circular polarization wave impedance bandwidth gap the antenna (S11-10dB) for 5.70-5.96GHz, after loading over the surface circular polarization axial ratio bandwidth is 5.03-6.22GHz, the gain of 6dB, the surface can also shield the work band electromagnetic interference. However, due to the high surface area size Too big, do not apply to requirements for the reader antenna miniaturization degree is very high, so the miniaturization method of the surface. The same slot antenna structure, super surface is only the surface of the 1/16 before the super size changed but super surface loading, need to be tightly abutted on the back side of the microstrip slot the patch antenna impedance bandwidth. After loading (S11-10dB) for 5.65-6.05GHz, the original axis of the slot antenna is 60dB, add a layer of super surface of rear axle ratio dropped to 1OdB, loading the two layer over the surface than the minimum rear axle is reduced to 5dB, loading the three layer of super surface rear axle ratio decreased to less than 3dB, the axial ratio bandwidth of 5.52-5.64GHz. visible increase, multilayer super surface, axial ratio bandwidth of the antenna can be extended, the axial ratio will be reduced. In addition, because the FR4 thickness increases, increase the equivalent dielectric constant, so the center frequency is reduced. Finally, the super surface rotation angle Effect on the polarization state of the invariant structure of slot antenna, size adjustment, impedance bandwidth (S11-10dB) is 5.53-5.90GHz. when the super surface and slot antenna alignment, can realize left-handed circular polarization axial ratio bandwidth is 5.74-5.85GHz, when rotated 90 degrees over the surface, can realize the right-hand circular polarization, axial ratio bandwidth of 5.78-5.94GHz. circle polarized antenna volume is only the principle of 25mm*25mm*4mm. polarization is achieved over the surface of different angles have different impedance phase difference, phase difference and +90 DEG -90 DEG phase difference circular polarized wave generated in different states, circular polarization rotating in the opposite direction.

【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN821.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前6條

1 楊放;衛(wèi)銘斐;王純;王民;周軍妮;;單點(diǎn)饋電高增益圓極化三角形微帶貼片天線設(shè)計[J];電子元件與材料;2015年05期

2 左衛(wèi);;短波通信系統(tǒng)發(fā)展及關(guān)鍵技術(shù)綜述[J];通信技術(shù);2014年08期

3 施瑤瑤;吳彤;劉友文;李艷;周融;;艾里光束自彎曲性質(zhì)的控制[J];光子學(xué)報;2013年12期

4 唐珂;;國外農(nóng)業(yè)物聯(lián)網(wǎng)技術(shù)發(fā)展及對我國的啟示[J];中國科學(xué)院院刊;2013年06期

5 鞠茂光;劉尚麟;;美國空軍短波全球通信系統(tǒng)技術(shù)分析[J];通信技術(shù);2013年07期

6 張澤;劉京郊;張鵬;倪培根;Prakash Jai;胡洋;姜東升;Christodoulides Demetrios N;陳志剛;;多艾里光束合成自聚焦光束的實驗實現(xiàn)[J];物理學(xué)報;2013年03期

，

本文編號：1380772