【摘要】：對于任何一個無線通訊系統(tǒng),天線都是一個不可或缺的部分。隨著通信系統(tǒng)的小型化發(fā)展趨勢,要求天線系統(tǒng)在保證其輻射特性的同時做到緊湊型。因為剖面低、加工制造簡單、易共形、方向圖多樣化等特點,微帶陣列天線的應(yīng)用背景十分廣泛。如何在不影響其他性能的條件下將微帶陣列天線尺寸降低是極具實用價值的研究課題。同時,正常工作的天線離不開饋電網(wǎng)絡(luò),隨著天線尺寸的縮小,饋電網(wǎng)絡(luò)的尺寸也應(yīng)該同步壓縮,以適應(yīng)緊湊型天線。本文圍繞著小型化的主題,研究了緊湊型微帶陣列天線陣元間的去耦網(wǎng)絡(luò)以及加載移相器的小型化饋電網(wǎng)絡(luò),具體研究內(nèi)容如下:1.簡要介紹了微帶天線及其陣列的基本理論。包括微帶天線的輻射機理與其表面波、表面電流產(chǎn)生機理;微帶陣列天線工作原理以及微帶陣列陣元間耦合的相關(guān)理論與介紹。為后續(xù)研究工作提供一定的理論基礎(chǔ)。2.設(shè)計了一款中心頻率在2.4GHz的三單元緊湊型微帶陣列天線,輻射貼片采用嵌入式微帶線饋電,避免因使用四分之一波長阻抗變換器而增大尺寸。陣元間距小于0.16λg(λg為對應(yīng)頻率的介質(zhì)中波長)實現(xiàn)了緊湊型特點。相鄰陣元間加載了交指諧振結(jié)構(gòu)構(gòu)成的去耦網(wǎng)絡(luò),該去耦網(wǎng)絡(luò)能夠極大程度上降低陣元間的互耦并改善隔離度,實現(xiàn)緊湊型微帶陣列天線。對所設(shè)計天線與參考天線進行建模仿真與加工測試,結(jié)果顯示:天線阻抗帶寬(11S≤-10 d B)為8.34%;在工作頻率2.4GHz處,參考天線的隔離度S12為-14d B,而在加載了設(shè)計的去耦網(wǎng)絡(luò)后,相應(yīng)的隔離度降低至-40d B;單個天線增益達1.9d B,E面的3d B波束寬度為85°,H面的3d B波束寬度為78°。測試結(jié)果與仿真結(jié)果有較高吻合度,證明了所設(shè)計去耦網(wǎng)絡(luò)優(yōu)異的性能,所設(shè)計天線可用于MIMO、相控陣等。3.復(fù)合左右手傳輸線的應(yīng)用研究。根據(jù)本論文研究設(shè)計的緊湊型微帶陣列天線,利用復(fù)合左右手傳輸線實現(xiàn)相位調(diào)控,設(shè)計了具有負相移功能的移相器,并采用T型功率分配器實現(xiàn)功率分配,最終提出了一款加載復(fù)合左右手傳輸線移相器的1:3饋電網(wǎng)絡(luò)。仿真與實驗表明,在2.35GHz~2.42GHz的頻率范圍內(nèi),饋電網(wǎng)絡(luò)能夠?qū)崿F(xiàn)等幅同相饋電。同時將該饋電網(wǎng)絡(luò)應(yīng)用在三單元的緊湊型微帶陣列天線。實測與仿真結(jié)果有較高的吻合度,證明所設(shè)計天線陣列與饋電網(wǎng)絡(luò)應(yīng)用價值。
[Abstract]:Antenna is an indispensable part of any wireless communication system. With the development of miniaturization of communication systems, antenna systems are required to be compact while ensuring their radiation characteristics. Because of its low profile, simple fabrication, easy conformal and diversified pattern, microstrip array antenna has a wide application background. How to reduce the size of microstrip array antenna without affecting other performance is of great practical value. At the same time, the normal operation of the antenna can not be separated from the feed network. With the reduction of the size of the antenna, the size of the feed network should also be compressed synchronously to adapt to the compact antenna. Around the theme of miniaturization, the decoupling network between antenna elements of compact microstrip array and the miniaturized feed network of loading phase shifter are studied in this paper. The research contents are as follows: 1. The basic theory of microstrip antenna and its array is briefly introduced. It includes the radiation mechanism of microstrip antenna and its surface wave, surface current generation mechanism, the working principle of microstrip array antenna and the related theory and introduction of coupling between microstrip array elements. To provide a theoretical basis for the follow-up work. 2. A three-unit compact microstrip array antenna with center frequency in 2.4GHz is designed. The radiation patch is fed by embedded microstrip line to avoid increasing the size due to the use of 1/4 wavelength impedance converter. The element spacing is less than 0.16 位 g (位 g is the wavelength in the medium corresponding to the frequency) and the compact type is realized. The decoupling network composed of cross-finger resonance structure is loaded between adjacent array elements. The decoupling network can greatly reduce the mutual coupling between the elements and improve the isolation degree and realize the compact microstrip array antenna. Modeling, simulation and machining test of the designed antenna and reference antenna show that the impedance bandwidth of the antenna (11s 鈮，

本文編號：2231489