一种宽带天线的研究与设计*

为了满足宽带通信的需求,利用U形单极子天线和两个U形寄生辐射元的方法,设计了一种共面波导馈电的宽带天线,其阻抗带宽达到85%。所设计的天线印刷在尺寸为20 mm×30 mm×1.6 mm、介电常数为265的聚四氟乙烯介质基板上。为了满足无线局域网（WLAN）和全球互联微波接入（WiMAX）的工作需要,抑制不需要的信号,在U形单极子辐射元之间插入一条调谐微带线,产生一个陷波特性,使所设计的天线满足WLAN、WiMAX和低端UWB通信需求。利用高频结构仿真软件HFSS对影响天线性能的主要参数进行仿真、分析和优化,得到天线的优化尺寸,并对优化的天线进行制造和测试。实验结果表明,该天线比传统微带贴片天线性能有了较大的提高,证明了利用共面波导馈电和寄生技术设计宽带天线的可行性和有效性。     

一种新型共面波导馈电单极子天线的设计与仿真

设计了一种简单的共面波导馈电单极子天线,给出了实验设计与仿真结果。结果表明,该天线具有良好的辐射特性,可覆盖GSM900、DCS1800、IEEE802.11.a、IEEE802.11.b和HiperLAN-2带宽。该天线体积小,尺寸仅为32mmx31mmx1.6mm,基板的介电常数为4.4。     

双频共面波导天线设计

本文提出了一种基于共面波导结构的工作频率在2.45GHz和5.8GHz的双频带天线的设计。该天线采用了增加突出结构和边缘开槽的方法,通过时域有限差分法(FDTD)对共面波导尺寸的变化进行了仿真与优化,得出了共面波导结构对天线性能的影响,从而给出了相应的结构尺寸。并实际测量了天线的反射参数以及方向图,对比测量结果与仿真结果基本符合。最后本文对本次天线设计做出总结并对测量结果做了误差分析。     

一种基于平面八木天线的小型化宽带滤波天线

设计了一种基于平面八木天线的小型化宽带滤波天线。平面八木天线由偶极子天线、引向器和反射器组成,其中反射器由地板充当。通过引入一个多模谐振器,使整个天线实现滤波响应。与传统的八木天线相比,所设计的滤波天线具有更宽的带宽,并且对高次谐波的抑制良好(抑制至16 GHz),同时在通带边缘体现出较高的选择性。仿真结果表明,该滤波天线的阻抗带宽为5.4~7.0 GHz,并在此带宽内实现了稳定的增益,平均增益约为3.7 dBi。滤波天线的整体尺寸为0.5λ_0×0.7λ_0(W×L),其中λ_0为中心频率6 GHz在自由空间的波长。     

基片集成波导多模宽带天线研究进展

基片集成波导由于其自身的独特优势,低剖面、易制作且易于平面电路集成,在天线中应用广泛。多模宽带、可重构、多输入多输出是当前天线发展的主要方向。阐述了当前基片集成波导多模宽带天线的主要实现方法和发展前景,为更好地设计基片集成波导多模宽带天线提供了依据。     

基于分形理论对天线的讨论

利用分形理论设计出的分形天线和分形天线阵,具有小巧、灵活、轻便、同时还具有多频带、宽频带和“自加载”特性,它们存在多种多样形式,在军事工业和通信行业将有很大的发展潜力。     

一种具有宽带特性的小型化双频双极化差分天线

提出了一种具有宽带特性的小型化双频双极化差分天线。天线由双层介质板组成。辐射贴片位于上层介质板上表面,低频谐振由方环贴片提供,高频谐振由方形贴片和寄生条带共同提供,其中方形贴片被方环贴片包围,形成紧凑的嵌套式结构,四个端口提供了两组正交的差分馈电对,使天线具有双极化特性。差分馈电的共模抑制特性可提高端口隔离度并降低交叉极化。     

一种基于分形结构的超宽带天线研究

基于微带天线和分形天线的基本理论,采用正方形和圆形交替的方法设计了用于超宽带（UWB）通信的分形天线。利用电磁仿真软件CST软件对所设计的天线进行仿真、优化,并分析了影响天线阻抗特性和辐射特性的关键参数。从仿真实验结果可以看出,所设计的天线有较好的全向辐射特性和宽的阻抗带宽,能够满足超宽带通信需求。     

类Minkowski分形天线的分析与设计

为了实现一款天线在ISM2.4G(2.4～2.483 5 GHz)、Bluetooth、GPS、WLAN(2.4～2.48 GHz)等多频段同时工作,设计了基于分形理论的类Minkowski分形微带天线,方案中对原有的Minkowski分形结构和接地板进行改进。通过仿真分析与优化设计使得天线尺寸缩减至90 mm×71 mm×1.6 mm,谐振频率为2 GHz,工作在0.93 GHz～3.02 GHz频段,相对带宽为105.82%,最大增益可达1.89 dB。最终天线能够进行良好的阻抗匹配,对天线带宽进行展宽,达到了超宽频带天线的要求。     

一种新型的阶梯螺旋天线

文章介绍了一种新型的阶梯螺旋天线,该方案可以通过在有限的柱体表面上绕更多的螺旋线来降低工作频率,从而实现天线的小型化,文中并以1.5g GPS天线为例,给出了传统螺旋天线和阶梯螺旋天线的对比,最终生产的阶梯螺旋天线测试和仿真结果保持一致.     

A coplanar waveguide‐fed flexible antenna for ultra‐wideband applications

This paper presents a novel ultra‐wideband (UWB) antenna printed on a 70 μm thick flexible substrate. The proposed antenna consists of a hybrid‐shaped patch fed by coplanar waveguide (CPW). The ground planes on opposite sides of the feeding line have different height to improve antenna bandwidth. Simulation shows that the proposed antenna maintain wide bandwidth when changing its substrate's thickness and dielectric constant, as well as bending the antenna on a cylindrical foam. The proposed antenna is fabricated in laboratory with a simple and low‐cost wet printed circuit board (PCB) etching technique. Measured bandwidths cover 3.06 to 13.58, 2.8 to 13.55, and 3.1 to 12.8 GHz in cases of flat state and bent with radii of 20 and 10 mm, respectively. Measured radiation patterns show the antenna is omnidirectional in flat and bent cases.     

Flower‐shaped ultra‐wideband fractal antenna

A flower‐shaped ultra‐wideband fractal antenna is presented. It comprises a fourth iterative flower‐shaped radiator, asymmetrical stub‐loaded feeding line, and coplanar quarter elliptical ground planes. A wide operating band of 12.12 GHz (4.58‐16.7 GHz) for S ₁₁ ≤ ? 10 dB is achieved along with an overall antenna footprint of 15.7 × 11.4 mm². In addition, other desirable characteristics, that is, omnidirectional radiation patterns, peak gain upto 5 dB, and fidelity factor more than 75% are achieved. A good agreement exists between the simulation and measured results. The obtained results illustrate that this antenna has wide operating range and compact dimensions than available structures.     

移动通信系统中的宽带智能天线技术

自适应信号处理是下一代高性能移动通信技术中一项重要的必不可少的技术。而宽带智能天线的自适应处理技术则是自适应技术中一个重要的研究分支。本文对无线通信中的智能天线自适应处理技术的发展和现状进行了介绍,针对宽带智能天线优化算法高复杂性,提出了一种新的基于频不变理论的波束优化,并对算法性能进行分析。     

A wideband dielectric resonator antenna array using air‐bridgeless coplanar waveguide power divider

In this communication a 2 × 2 dielectric resonator antenna (DRA) array is proposed with a wideband frequency response. An air bridgeless coplanar waveguide (CPW) power divider network is first time used to feed the 2 × 2 DRA array. Four rectangular DRAs are used as array element and exited in TE₁₁₁ mode by four slots at the end of the CPW lines in the feed network. The straight CPW phase delay line in feed network is further meandered resulting an enhanced radiation performance. The proposed DRA array exhibits a wideband response with an impedance bandwidth of 16% while maintaining a stable broadside radiation pattern with the gain range from 8 to 9.4 dBi. The proposed design is fabricated and measured, reaching good agreement with simulation results.     

Wideband printed slot antenna using Koch fractal metasurface structure

A novel wideband slot antenna with Koch fractal metasurface structure is presented in this letter. Using Koch metasurface as a slot edge, the proposed antenna obtains excellent performance in bandwidth. For optimal bandwidth, optimization is done for both iteration angle (IA) and iteration factor (IF) at each iteration order (IO). The measured results show that the impedance bandwidth of the optimized antenna can reach about 1.75 octaves (1.45‐4.86 GHz) for VSWR ≤ 2. In addition, stable radiation patterns are observed over the whole operating band of the proposed antenna.     

宽带分形阵列天线的设计及其耦合分析

设计了一种新型的分形微带天线,提出了一种扩展天线带宽的方法,此方法可将天线带宽提高将近6倍,相对阻抗带宽从4.9%提高到30%左右.然后根据天线频率可重构形成的基本原理,在此宽带天线基础上引入了三个MEMS开关,通过改变开关的状态,切换调整分形微带天线组合结构,使天线能工作在三个频段,扩展了天线工作带宽.以此超宽带分形...     

Wideband constant beamwidth coplanar waveguide‐fed slot antennas using metallic strip loadings and a widened tuning stub with shaped reflectors

Sectored antennas with wideband operation for wireless communication systems are presented. The proposed configurations are based on a coplanar waveguide fed slot antenna using metallic strip loadings and a widened tuning stub above various reflector shapes. By shaping the reflector, noticeable enhancements in both unidirectional radiation pattern and beamwidth can be achieved while maintaining the simple fabrication and installation. Based on the results obtained, three sector antennas covering 72°, 90°, and 120° beamwidths suitable for five, four, and three sectors, respectively, have been proposed and designed. The simple structural configurations, low cost, and ease of half power beamwidth control of the proposed antennas make the design very attractive for practical implementation. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.