【作者】 崔悦慧；

【导师】 李融林；

【作者基本信息】 华南理工大学 ， 信息与通信工程， 2014， 博士

【摘要】 基站天线作为移动通信系统的重要组成部分，对移动通信网络的性能有直接且重要的影响。随着通信技术的发展，相继出现了使用不同频段的移动通信系统，对基站天线的研究进入到一个宽带化、多频化、双极化、小型化的时代。本论文主要研究了宽带平面基站天线的设计方法，并提出了五种具有平面结构的新型宽带基站天线。本论文的创新性内容包含以下五个方面：1.提出了一种宽带平面基站天线，天线由一对半波振子构成，通过一段共面微带线并联，用一段L形微带线耦合馈电。详细分析了共面微带线、L形微带线以及天线距离反射板的高度对宽带平面基站天线带阻抗带宽的影响。实验结果表明天线15-dB带宽为54%,覆盖1.65-2.85GHz频段，方向图稳定，增益9dBi。以宽带平面天线为单元，设计了八单元宽带平面基站天线阵列，适用于移动通信基站系统。2.从宽带平面基站天线出发，提出了一种宽带平面45°双极化基站天线，天线由二个宽带平面天线单元构成。详细研究了宽带平面45°双极化基站天线的排布对隔离度的影响；实验结果表明天线15-dB带宽为48%（覆盖1.69-2.78GHz），隔离度为30dB。以宽带平面45°双极化基站天线为单元，设计了八单元的宽带平面45°双极化基站天线阵列。3.从宽带平面基站天线出发，提出了一种宽带平面垂直/水平双极化基站天线，天线由二个正交放置的宽带平面基站天线单元构成。该天线使用了同一天线单元的E面（水平极化）和H面（垂直极化）作为不同极化的水平面方向图，通过反射板的设计，使得二种极化的水平面半功率波束宽度都为62.53°。实验结果表明天线15-dB带宽为47%（覆盖1.7-2.75GHz），隔离度为30dB。在天线单元基础上，设计了一个八单元的宽带平面垂直/水平双极化基站天线阵列。4.提出了一种应用于LTE700/GSM850/GSM900频段的宽带平面双极化四叶草基站天线，天线由二个交叉蝶形振子构成，用一小段微带线馈电，这种馈电方式可避免使用任何形式的空气桥、跳线、短路探针以及耦合探针等结构，使天线为紧凑的平面结构。由于蝶形振子之间的耦合，天线获取了宽带性能。实验表明天线15-dB带宽约为50%（覆盖0.63-1.04GHz），隔离度为35dB。以此天线为阵元，设计了应用于LTE700/GSM850/GSM900频段的四单元宽带平面双极化四叶草基站天线阵列。由于尺寸小、带宽大，还设计了应用于2G/3G/LTE(4G)频段的宽带平面双极化四叶草基站天线及其八单元阵列。5.提出了一种宽带平面双频基站天线，天线由一个低频单元和二个高频单元构成，低频单元和高频单元都采用印刷振子结构，高频单元嵌套于低频单元的留白空间，形成了紧凑的平面结构。实测结果表明该天线低频带宽为20%（覆盖800-980MHz），高频带宽为60%（覆盖1540-2860MHz）。设计了一个适用于2G/3G/LTE(4G)频段的四单元低频天线阵列和八单元高频天线阵列的宽带平面双频基站天线阵列，高、低频以2:1的单元数进行组阵，可避免在高频段出现栅瓣。通过上述五个方面的研究，对宽带平面基站天线的工作原理和设计方法进行了深入系统的探索和研究，丰富了宽带基站天线的天线结构与设计理论。更多还原

【Abstract】 As important components of mobile communication systems, base station antennas havedirect and important influences on the performance of the mobile communication networks.With the development of communication technology, different mobile communicationsystems have been designated with different frequency bands, which need broadband,multi-band, dual-polarized and miniaturized base station antennas. The mian focus of thisdissertation is on the design techniques of novel broadband planar base station antennas. Fivebroadband base station antennas with planar configurations are proposed. The maininnovative contributions of the dissertation are summirzed as follows:1. A broadband planar base station antenna is proposed. The antenna consists of a pair ofhalf-wave dipoles, which are connected in parallel through a coplanar stripline andcoupling fed by an L-shaped microstrip line. The influences of coplanar microstrip line,the L-shaped microstrip line and the distance between the antenna and reflector on theimpedance bandwidth are investigated. Experimental results show that the antenna has a15-dB bandwidth of54%(1.65-2.85GHz). The antenna gain is9dBi. The radiationpatterns are stable. An eight-element broadband planar antenna array is developed forbase station application.2. A broadband planar45°dual-polarized base station antenna is developed based on thebroadband planar base station antenna. The antenna consists of two broadband planarbase station antenna elements. The influence of different arrangements for the45°dual-polarized antenna elements on the isolation is investigated. Experimental resultsshow that the antenna has a15-dB bandwidth of48%(1.69-2.78GHz) and a highisolation of30dB. An eight-element broadband planar45°dual-polarized antenna arrayis designed for base station applications.3. A broadband planar vertically/horizontally (V/H) polarized base station antenna isproposed based on the broadband planar base station antenna. The antenna is composedof two perpendicularly placed broadband planar base station antenna elements. Thehorizontal plane is the H-plane for the vertically polarized (VP) element and the E-planefor the horizontally polarized (HP) element. By shaping the reflector for the antenna, ahalf-power beam width of62.53°is achieved for both vertical and horizontalpolarizations. The antenna has a15-dB bandwidth of47%(1.7-2.75GHz), an isolation of30dB. An eight-element broadband planar V/H dual-polarized antenna array is developed for wireless communication applications.4. A broadband planar dual-polarized four-leaf clover antenna is proposed forLTE700/GSM850/GSM900base station application. The antenna is composed of twoperpendicularly crossed bow-tie dipoles. Each bow-tie dipole is excited by a microstripline. This type of feeding structure avoids using any wire bridge, wire bonding, shortingpin, or feeding probe, making the dual-polarized antenna planar and compact. Due to thecoupling between two bow-tie dipoles, the antenna achieves a broadband bandwidth.Experimental results show that the antenna has a15-dB bandwidth of50%(0.63–1.04GHz) with an isolation of35dB. A four-element broadband planar dual-polarizedfour-leaf clover antenna array is developed, which is suitable forLTE700/GSM850/GSM900base station application. Since the antenna has advantages ofsmall size and large bandwidth, a broadband planar dual-polarized antenna and itseight-element array are also developed for2G/3G/LTE (4G) base station applications.5. A dual-broadband planar base station antenna is presented. The antenna consists of a pairof printed dipoles for the lower band and two pairs of printed dipoles for the upper band.The upper-band elements are nested inside the lower-band element. Therefore the antennahas a planar and compact configuration. The antenna achieves a bandwidth of20%(800-980MHz) for the lower band and a bandwidth of60%(1540-2860MHz) for theupper band. A four-element dual-broadband planar antenna array is designed for2G/3G/LTE (4G) application, which leads to a4-element array for the lower band and an8-element array for the upper band. Since the number of elements for the upper-bandarray is twice of that for the lower-band array, the grating lobes can be avoided.This thesis has conducted a comprehensive investigation and research on the operationprinciple and design tecnniques for the broadband planar base station antennas. New methodsfor the design of the broadband antenna are provided.更多还原