本文關鍵詞： 基站天線 圓極化天線 多輸入多輸出(MIMO)天線 八木天線 穩(wěn)定的輻射方向圖 交叉極化比 寬軸比波瓣寬度 定向天線 階梯型反射器　出處：《華南理工大學》2015年博士論文　論文類型：學位論文

【摘要】：隨著移動通信4G時代的到來以及向5G時代的邁進,多偶極子天線在移動通信系統(tǒng)中的作用會越來越重要。通過控制多個偶極子上電流幅度、相位以及空間位置之間的關系,多偶極子天線可以廣泛應用于基站天線、圓極化天線、多輸入多輸出(MIMO)天線以及八木天線中。本研究課題主要創(chuàng)新工作有:1.提出了一種在寬頻段內(nèi)實現(xiàn)天線輻射方向圖穩(wěn)定的方法。通過合理的設計偶極子和反射板的位置,就可以使天線在寬頻段內(nèi)實現(xiàn)穩(wěn)定的輻射方向圖。我們設計、加工和測試了兩個單極化的基站天線來驗證我們所提出的方法。測試結果顯示,我們設計的天線都在寬頻段內(nèi)實現(xiàn)了穩(wěn)定的輻射方向圖、良好的阻抗匹配以及低交叉極化。2.為了減小電磁波傳播的多徑衰落效應以及為了能夠和射頻封裝器件相連接,我們提出了一款±45°雙極化差分基站天線。這款天線水平面內(nèi)半功率波瓣寬度穩(wěn)定在65度左右,非常適合應用在三扇區(qū)的蜂窩基站天線中。3.提出了兩種改善±45°雙極化基站天線交叉極化比的方法。第一種方法是在一個基本的±45°雙極化基站天線周圍加載4個水平的寄生單元。第二種方法是在一個基本的±45°雙極化基站天線和反射板之間加載四個垂直的寄生單元。我們設計、加工、測試了兩款±45°雙極化基站天線來驗證我們所提出兩種的方法。4.提出了兩種實現(xiàn)圓極化天線在寬角度內(nèi)低軸比的方法。第一種方法是將四個偶極子圍成正方形。我們將兩對相互垂直放置的偶極子幅度相等相位相差90度激勵。只要合理的設計偶極子之間的距離,就可以使圓極化天線在寬角度內(nèi)實現(xiàn)低軸比。為了減小圓極化天線的整體尺寸,我們用彎折偶極子代替了直線型偶極子。第二種實現(xiàn)圓極化天線寬角度內(nèi)低軸比的方法是在一個交叉偶極子圓極化天線和反射板之間加載四個垂直的寄生單元。我們設計、加工、測試了三款圓極化天線來驗證我們所提出的兩種方法。5.提出了一種由H型定向天線組成的MIMO天線。我們提出的H型定向天線在沒有引向器和反射器的情況下,在水平面內(nèi)實現(xiàn)了很高的前后比。我們將四個這樣的H型定向天線圍成方環(huán)形組成一個緊湊的MIMO天線。這個MIMO天線單元之間的隔離度都很高。我們將這款MIMO天線加工測試并評估了它的MIMO特性。6.提出了帶有階梯型反射器的八木天線。由于反射器采用的階梯型結構,因此反射器的長度可以比偶極子要短。我們通過分析一個偶極子和一個寄生單元的等效電路解釋了階梯型結構可以縮短反射器尺寸的原因。我們將這種階梯型反射器應用在了一個同軸饋電的八木天線和一個差分饋電的八木天線當中,并將這兩個八木天線加工測試。
[Abstract]:With the arrival of 4G era and the development of 5G era, the role of polydipole antenna in mobile communication system will become more and more important. Polydipole antennas can be widely used in base station antennas, circularly polarized antennas, In the multi-input multiple-output MIMO-antenna and the Yagi antenna, the main innovative work of this research is: 1.A method to stabilize the radiation pattern of the antenna in the broadband band is proposed. The position of the dipole and the reflector is reasonably designed. We design, process and test two single-polarization base station antennas to verify our proposed method. Our antennas are designed to achieve stable radiation patterns, good impedance matching and low cross-polarization. 2. In order to reduce the multipath fading effect of electromagnetic wave propagation and to be able to connect with RF packaging devices, We propose a 鹵45 擄dual-polarization differential base station antenna. The width of the half-power lobe in the horizontal plane is stable at about 65 degrees. This paper presents two methods to improve the cross-polarization ratio of 鹵45 擄dual polarization base station antenna. The first method is to load 4 water around a basic 鹵45 擄dual polarized base station antenna. Flat parasitic elements. The second method is to load four vertical parasitic elements between a basic 鹵45 擄dual-polarized base station antenna and a reflector. Processing, Two 鹵45 擄dual-polarization base station antennas are tested to verify the two methods proposed. 4. Two methods are proposed to realize the low axis ratio of circular polarized antennas at wide angles. The first method is to encircle the four dipoles into squares. Two pairs of dipoles placed perpendicular to each other are excited by 90 degrees in equal phase. If the distance between dipoles is reasonably designed, In order to reduce the overall size of circularly polarized antenna, a low axis ratio can be realized at a wide angle. We replace the linear dipole with a curved dipole. The second method to realize the low axial ratio in the wide angle of a circular polarized antenna is to load four vertical parasitic elements between a cross dipole circular polarization antenna and a reflector. Three circularly polarized antennas are processed and tested to verify the two methods proposed. 5. A MIMO antenna consisting of H-type directional antennas is proposed. The H-type directional antenna is presented without a guide and reflector. We make four H-shaped directional antennas into a square ring to form a compact MIMO antenna. The isolation between the MIMO antenna elements is very high. We will take this MIMO antenna. Processing test and evaluation of its MIMO characteristics. 6. Proposed a step reflector with the Yagi antenna. So the length of the reflector can be shorter than that of the dipole. We explain the reason why the step structure can shorten the size of the reflector by analyzing the equivalent circuit of a dipole and a parasitic unit. The emitters are used in a coaxially fed Yagi antenna and a differential fed Yagi antenna. And the two Yagi antenna processing test.
【學位授予單位】：華南理工大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TN821.4

【參考文獻】

相關博士學位論文 前1條

1 崔悅慧;新型寬帶平面基站天線研究[D];華南理工大學;2014年

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本文編號：1513111