本文選題：MIMO + 平面倒F天線��； 參考：《電子科技大學(xué)》2014年博士論文

【摘要】：與當(dāng)前主流的移動通信標(biāo)準(zhǔn)(2G/3G)相比,未來的移動通信系統(tǒng)能夠提供更廣闊的智能暢享體驗(yàn)。未來的移動通信可以跨越不同的頻帶,也可以在任何地方用寬帶接入互聯(lián)網(wǎng)(包括衛(wèi)星通信和平流層通信),并且能夠提供定位定時、數(shù)據(jù)采集、遠(yuǎn)程控制等綜合服務(wù)功能。然而,MIMO多天線技術(shù)作為未來移動通信中最重要的環(huán)節(jié),其性能的優(yōu)劣程度完全可以決定整個系統(tǒng)的通信質(zhì)量,移動通信中的MIMO多天線技術(shù)已然成為了當(dāng)前學(xué)者們研究的熱門方向。在這類研究中,主要難點(diǎn)就在于天線系統(tǒng)的高隔離度、寬頻帶與小型化三者之間不可調(diào)和的矛盾。首先,手持移動終端單元天線的設(shè)計很難同時滿足小型化、寬帶化和多頻化的要求;其次,通信應(yīng)用中的MIMO天線系統(tǒng)輻射場的非正交特性也容易造成模式互耦以及高相關(guān)性,因此,多天線技術(shù)在手持終端的應(yīng)用中受到極大的限制。即使采用分集技術(shù),隨之產(chǎn)生的體積增大的問題也不利于手機(jī)天線與射頻前端電路(饋電網(wǎng)絡(luò))集成。本文分別以平面結(jié)構(gòu)的寬頻帶、小型化彎折單極子與PIFA天線為單元,利用了混合環(huán)饋電設(shè)計,對基于模式分集的小型化2×2 MIMO移動終端天線系統(tǒng)設(shè)計的理論與技術(shù)進(jìn)行了詳細(xì)的研究。此設(shè)計具有隔離度高、結(jié)構(gòu)緊湊、工作頻帶寬等主要優(yōu)點(diǎn)。論文主要內(nèi)容概括如下:一、本論文首先介紹了移動通信中MIMO多天線系統(tǒng)常規(guī)的分集技術(shù)原理及實(shí)現(xiàn)方法;針對強(qiáng)耦合環(huán)境下,移動終端MIMO多天線系統(tǒng)相關(guān)性過高的難題提出了模式分集的解決方案;同時通過引入電多極、磁多極展開的基本概念,介紹了模式分集的理論基礎(chǔ),并規(guī)劃出模式分集方案在工程實(shí)現(xiàn)中的技術(shù)路線;最后,根據(jù)移動通信標(biāo)準(zhǔn)要求提出了本項目設(shè)計中相關(guān)的技術(shù)指標(biāo)。二、本論文中,還對移動終端單元天線進(jìn)行了研究,移動終端設(shè)備往往要求天線在小型化的同時,也能實(shí)現(xiàn)低頻、多頻且寬頻工作,針對這一問題,提出了一種多頻工作的地板開槽PIFA天線。首先,該天線采用常規(guī)的探針饋電形式,結(jié)構(gòu)簡單,便于集成,且加工的容差度較高,能有效地保證天線成品加工一致性,降低加工成本;在此基礎(chǔ)之上,利用了集總元件加載,地板開槽和彎折枝節(jié)等方法,實(shí)現(xiàn)了天線結(jié)構(gòu)的小型化;此外,在設(shè)計中首次提出了雙短路點(diǎn)PIFA天線的調(diào)諧設(shè)計,能夠在實(shí)現(xiàn)多頻段工作的同時,進(jìn)一步拓展天線的阻抗帶寬,在GSM850/900、DCS、PCS、LTE2300/2500、WLAN 11.b、WLAN 11.a、WiMAX、IMT-Advanced頻段上實(shí)現(xiàn)良好的手機(jī)單元天線工作性能。三、本論文還對適用于MIMO多天線系統(tǒng)中的混合環(huán)饋電結(jié)構(gòu)進(jìn)行了小型化設(shè)計。應(yīng)用于MIMO多天線系統(tǒng)的混合環(huán)饋電結(jié)構(gòu)需要滿足兩個要求:一是必須產(chǎn)生具有正交特性的共模與差模,有效地降低其相關(guān)性;二是保證兩端口之間有較高的隔離度。此外,饋電結(jié)構(gòu)必須盡可能的緊湊。針對上述難點(diǎn),經(jīng)過理論分析和創(chuàng)新,在設(shè)計中首次采用了多彎折線結(jié)構(gòu)和平行耦合線反相器的集成設(shè)計。最后進(jìn)行了實(shí)驗(yàn)仿真并且加工測試,實(shí)現(xiàn)了混合環(huán)饋電結(jié)構(gòu)的雙頻且寬頻工作,保證了端口間具備良好的隔離效果。四、最后,在本論文最后一部分中,作者對對適用于MIMO多天線系統(tǒng)中的混合環(huán)饋電結(jié)構(gòu)進(jìn)行了小型化設(shè)計。針對MIMO多天線系統(tǒng)在實(shí)際應(yīng)用中出現(xiàn)的差模端口低頻部分阻抗匹配效果差的問題,提出了匹配網(wǎng)絡(luò)調(diào)諧和阻抗?jié)u變線兩種方案,在一定程度上改善了差模端口低頻部分的阻抗匹配特性。但是,為了更好地實(shí)現(xiàn)低頻條件下的寬帶工作,還對工程實(shí)際中的模式分集方式的內(nèi)涵進(jìn)行豐富和完善。然后,以完善后的模式分集理論為指導(dǎo),對差模端口的角度配對進(jìn)行了合理的篩選。同時,充分驗(yàn)證了非180°混合環(huán)設(shè)計的可行性。通過加工測試,證明了該設(shè)計可以使差模端口低頻的阻抗匹配特性得到徹底地改善。
[Abstract]:Compared with the current mainstream mobile communication standards (2G/3G), future mobile communication systems can provide a broader and more intelligent experience. Future mobile communications can cross different bands, and can also use broadband access to the Internet (including satellite communications and flow layer communications) anywhere, and can provide location timing, data acquisition. However, as the most important part of the future mobile communication, MIMO multi antenna technology can determine the communication quality of the whole system. The MIMO multi antenna technology in mobile communication has become a hot research direction of the current scholars. In this kind of research, the main difficulty is the main problem. It is the irreconcilable contradiction between the high isolation of the antenna system, the broadband and the miniaturization. First, the design of the mobile terminal unit antenna is difficult to meet the requirements of miniaturization, broadband and multi frequency. Secondly, the non orthogonal characteristics of the radiation field of the MIMO antenna system in the communication application can also easily cause the mutual coupling of the mode and the mode of the radiation field of the MIMO antenna system. High correlation, therefore, the multi antenna technology is greatly restricted in the application of handheld terminals. Even using diversity technology, the problem of volume enlargement is not conducive to the integration of mobile antenna and RF front end circuit (feed network). This paper is based on the wide band of planar structure, miniaturized bent monopole and PIFA antenna, respectively. Using the hybrid ring feed design, the theory and technology of the design of a miniaturized 2 x 2 MIMO mobile terminal antenna system based on pattern diversity are studied in detail. This design has the advantages of high isolation, compact structure and wide bandwidth. The main contents of this paper are summarized as follows: first, this paper first introduces the MIMO in mobile communication. The conventional diversity principle and realization method of antenna system are proposed. In the strong coupling environment, the solution of pattern diversity is proposed for the problem of high correlation of MIMO multi antenna system in mobile terminal. By introducing the basic concept of electric multipole and magnetic multipole expansion, the theoretical basis of model diversity is introduced, and a pattern diversity scheme is planned. In the end, according to the requirements of mobile communication standard, the related technical indexes are put forward in accordance with the requirements of mobile communication standard. Two. In this paper, the mobile terminal unit antenna is also studied. The mobile terminal equipment often requires the antenna to be miniaturized, and can also realize low frequency, multi frequency and broadband work, aiming at this question. A multi frequency PIFA antenna for floor slotting is proposed. First, the antenna is used as a conventional probe feed, which is simple in structure and easy to integrate, and has a high tolerance. It can effectively ensure the consistency of the finished product and reduce the processing cost. On this basis, the lumped element loading, the floor slotting and the bending branch are used. In addition, the tuning design of the dual short-circuit point PIFA antenna is proposed for the first time in the design. At the same time, the impedance bandwidth of the antenna can be further expanded and the good mobile phone is realized on the GSM850/900, DCS, PCS, LTE2300/2500, WLAN 11.b, WLAN 11.a, WiMAX, IMT-Advanced band. Three, three, this paper also miniaturized the hybrid ring feed structure suitable for the multi antenna system. The hybrid loop feed structure applied to the MIMO multi antenna system needs to meet two requirements: one must produce common mode and differential mode with orthogonal characteristics, effectively reduce its correlation; two is to guarantee two There is a high isolation between ports. In addition, the feed structure must be as compact as possible. In view of the above difficulties, through theoretical analysis and innovation, the integrated design of multi bending and parallel coupled line inverter is adopted for the first time in the design. Finally, the experiment simulation and the addition test have been carried out to realize the dual frequency of the hybrid ring feed structure. And the wide-band work ensures good isolation effect between ports. Four. Finally, in the last part of this paper, the author miniaturized the hybrid ring feed structure applied to the MIMO multi antenna system. The low frequency part impedance matching effect of the differential mode port in the practical application of the MIMO multi antenna system is poor. Two schemes of matching network tuning and impedance gradient are proposed, which improve the impedance matching characteristic of the low frequency part of the differential mode port to a certain extent. However, in order to better realize the broadband work under the low frequency conditions, the connotation of the pattern diversity in the engineering practice is enriched and perfected. At the same time, the feasibility of the design of the non 180 degree hybrid ring is fully verified. It is proved that the design can improve the impedance matching characteristic of the low frequency of the differential mode port thoroughly.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TN919.3;TN820
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本文編號：1957990