可用于WLAN的双频MIMO天线设计

设计了一款可用于WLAN的双频MIMO天线。天线的正面为L型单极子,背面为金属接地板。通过在接地板上加载耦合枝节使天线具有双频特性。同时,为了天线的小型化,对耦合枝节进行了弯折处理,减小天线尺寸。在两个天线单元之间加载T型寄生枝节和刻蚀矩形缝隙来提高天线的隔离度。使用电磁仿真软件和矢量网络分析仪对天线进行仿真和实测,结果表明：天线的工作频段为2.4～2.55 GHz和5.1～6.3 GHz,覆盖了WLAN的频段,同时在低频段内隔离度高于19 dB,高频段内隔离度高于25 dB。此外,天线的包络相关系数小于0.01且具有全向辐射特性。天线整体性能较好,可以满足WLAN的需求。     

小型双陷波共面波导馈电超宽带天线仿真分析

提出了一种结构简单具有双陷波特性的多用途共面波导馈电超宽带天线。在天线中嵌入了一种缝隙获得了双陷波特性。通过数值仿真对天线的阻抗特性、方向图和增益进行了研究。结果显示该天线在2.9～12GHz的频段内驻波比小于2.2,其中的3.55～3.67GHz及5.58～6.00GHz的范围内具有陷波特性。     

毫米波宽带双陷波MIMO天线设计

为有效抑制部分毫米波通信信号干扰,实现无线通信设备小型化,设计了一款具有双陷波特性的毫米波宽带MIMO天线。天线基本单元由辐射单元、微带馈线、Rogers RO4350B基板以及接地板构成。通过在天线辐射贴片刻蚀U型槽,以及接地板添加倒U型枝节,可在工作频段内产生双陷波特性;进一步在接地板引入圆形开槽使MIMO天线获得良好的隔离度。该天线结构紧凑,尺寸仅为26.7 mm×16.67 mm×1.524 mm,工作于21～40 GHz频段,其中陷波频段为22.04～24.72 GHz和25.96～31.2 GHz。结果表明：该天线在工作频段内隔离度大于20 dB,最大增益可达8.49 dBi,包络相关系数(ECC)均小于0.002,具有良好的辐射和增益性能,在毫米波超宽带通信中具有应用潜力。     

一种微带馈电的双阻带超宽带天线设计

设计了一种具有双阻带的超宽带天线。该天线由一个梯形的辐射单元和一个开有矩形槽的地板构成。并且通过在地板上开L 型和U 型缝隙,实现双阻带特性。该结果表明,天线工作带宽（VSWR<2）为8.6 GHz（2.9～11.5 GHz）,覆盖了UWB 频率范围,在3.2～3.9 GHz 和5～5.9 GHz 处形成了两个阻带,同时,这种天线在整个工作频率范围内有 良好的辐射方向特性。     

基于双枝节“U”型谐振器的双频段微带带通滤波器

利用一种新型的双枝节"U"型谐振器结构,设计了一款双通带微带带通滤波器。该谐振器是在"U"型谐振器的中间和侧臂上各引入了一个枝节得到的,调节侧臂上枝节的特性导纳能够在不改变一次谐波与基波频率比f_1/f_0的情况下自由改变二次谐波与基波频率比f_2/f_0的值,该特性能在实现指定的双通带的同时获得较好的带外抑制性能。对中心频率分别为0.9GHz和1.36GHz,相对带宽分别为12%和4%的双频段的微带带通滤波器进行了仿真和测试,测试结果与仿真结果吻合良好,证实了该双枝节谐振器的有效性。     

一种高隔离度的双倒L形双频MIMO天线设计

研究了一种微带线馈电的双倒L形双频MIMO印刷天线结构,通过在倒L单极子结构上加载一条倒L形地板枝节,实现了天线的双频特性;通过在天线单元之间加载一条T形去耦枝节,有效提高了天线单元之间的隔离度。实验结果表明,天线在S11≤-10 dB时,工作频段分别为2.39~2.53 GHz和4.92~6.15 GHz,相对带宽分别为5.7%和22.2%,工作频段内隔离度均大于18 dB。此外,天线整体辐射特性较好,结构简单并易于制作,可应用于WLAN无线通信系统。     

具有三陷波特性的类Sierpinski分形超宽带天线

为避免窄带通信系统对超宽带(ultra-wideband,UWB)系统的干扰冲突,提出一款具有三陷波特性的类Sierpinski分形UWB天线.辐射贴片采用圆环与五角星形嵌套迭代的2阶类Sierpinski分形结构,并采用缺陷地结构接地板以实现良好的UWB特性.通过在分形结构的上部添加对称倒L形开路枝节,在微带馈线两侧添加对称L形开路枝节,并在馈线处刻蚀倒π形窄缝隙产生了4.5～4.8 GHz、7.2～7.8 GHz和8.0～8.5 GHz三个频段的陷波特性.仿真和实测结果表明,天线在3.1～18.1 GHz的频段内,可有效抑制国际卫星波段、X卫星波段和国际电信联盟波段等窄带系统的干扰.该天线除滤波频段内,在通带频段内有较稳定的增益和全向辐射特性,可用于各种UWB系统中.     

具有三陷波特性的类Sierpinski分形超宽带天线

为避免窄带通信系统对超宽带(ultra-wideband,UWB)系统的干扰冲突,提出一款具有三陷波特性的类Sierpinski分形UWB天线.辐射贴片采用圆环与五角星形嵌套迭代的2阶类Sierpinski分形结构,并采用缺陷地结构接地板以实现良好的UWB特性.通过在分形结构的上部添加对称倒L形开路枝节,在微带馈线两侧添加对称L形开路枝节,并在馈线处刻蚀倒π形窄缝隙产生了4.5～4.8 GHz、7.2～7.8 GHz和8.0～8.5 GHz三个频段的陷波特性.仿真和实测结果表明,天线在3.1～18.1 GHz的频段内,可有效抑制国际卫星波段、X卫星波段和国际电信联盟波段等窄带系统的干扰.该天线除滤波频段内,在通带频段内有较稳定的增益和全向辐射特性,可用于各种UWB系统中.     

具有优越陷波选择性和带宽的超宽带缝隙天线

提出一种具有改善陷波特性的超宽带缝隙天线,该天线由T形微带枝节馈电的矩形缝隙天线来实现超宽频阻抗带宽,由嵌入在T形枝节上的1 4波长缝隙和地板上的一对1 4波长的缝隙构成两阶滤波器,实现陷波优越的选择形和带宽特性。另外,可以通过调整所嵌入的缝隙的宽度和位置来调节陷波的带宽。该天线具有较好的全向辐射特性,可以应用在各种超宽带通信系统中。     

一种小型化五频段可重构蝶形天线的设计

提出了一种新型多频段可重构天线.该天线采用小型平面蝶形结构,尺寸为35.0mm×38.0mm×1.6mm,由U型馈电带线、矩形寄生单元和接地面构成.通过调节馈电带线的长度和选择寄生单元,改变天线的局部结构和表面电流分布,从而获得不同的工作频段.该天线可在1.94～2.22GHz、2.32～2.54GHz、3.08～3.78GHz、3.63～4.83GHz、4.82～6.85GHz五种频段之间实现可重构,覆盖了主要的无线通信系统工作频段,各个状态具有良好的全向辐射特性和较高增益.因此,具有较大的实用价值.     

Compact printed ultra-wideband monopole antenna with dual band-notch characteristic

A compact ultra-wideband microstrip-fed planar antenna with dual band-notch characteristic is presented. Two notched frequency bands are achieved by embedding an E-slot in the radiation patch and a U-slot defected ground structure in the feeding line. Moreover, the two notched bands can be controlled by adjusting the length of the corresponding slot. Experimental results show that the proposed antenna, with compact size of 35 x 14 mm, has an impedance bandwidth of 2.87-10.91 GHz for a voltage standing-wave ratio less than 2, except two frequency notched bands of 3.49-4.12 and 5.66-6.43 GHz.     

3.5/5.5 Ghz dual band-notch ultra-wideband antenna

A compact and simple design of a CPW-fed planar antenna for ultra- wideband application with dual band-notch characteristics is presented. The proposed antenna yields an impedance bandwidth of 3.1- 10.6 GHz with VSWR < 2, except the bandwidths of 3.3-3.9 GHz for WiMAX and 5-6 GHz for WLAN. The antenna is successfully simulated, designed, and measured, showing broadband matched impedance, stable gain and omnidirectional radiation patterns.     

Dual Band-Notched Small Monopole Antenna with Enhanced Bandwidth for UWB Applications

This article proposes a novel printed monopole antenna for ultra wideband applications with dual band-notch function. The antenna consists of a disc-shaped radiating patch with a pair of folded strips arms, and a ground plane with a two L-shaped conductor backed plane, which provides a wide usable fractional bandwidth of more than 140 % (2.6–14.43 GHz). In order to generate single band-notch characteristics, we use a modified disc-shaped radiating patch with a pair of folded strips arms also by using this modified radiating patch, additional resonance is excited and hence much wider impedance bandwidth can be produced, especially at the higher band. By adding two L-shaped conductor backed plane in the ground plane a dual band notch function is achieved. The measured results reveal that the presented dual band-notch monopole antenna offers a very wide bandwidth with two notched bands, covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX and 4 GHz C bands. The designed antenna has a small size of $12\times 18\,\hbox {mm}^{2}$ .     

Band-notched ultra-wideband printed open-slot antenna using variable on-ground slits

A novel modified printed ultra-wideband (UWB) slot antenna with a square structure and a trapezoid tuning stub as well as a band-notch characteristic is presented. By embedding two L-shaped slits at the edge of the open radiating slot, a tunable notched band, for avoiding interference between the UWB and WLAN systems, is achieved. Moreover, by optimising the dimensions of the polygon-like slot and tuning stub, the impedance bandwidth and matching of the antenna can be improved. The realised slot antenna operates over 2.6-13.6 GHz for VSWR < 2 and has a rejected band of 4.9-5.85 GHz.     

频率可重构超宽带天线研究

超宽带天线和可重构天线是当今天线领域研究的热点。将可重构天线技术应用到超宽带天线设计中,讨论了频率可重构超宽带天线的设计思路。以印刷单极子椭圆天线为原型,给出了两个可重构天线的具体结构,并对天线进行了可重构带阻设计,避免与相关频段之间的干扰。仿真结果表明:重构后天线Ⅱ的低频获得了扩展,其相对尺寸的长和宽分别减小到最大工作波长的0.116倍和0.087倍,工作频段为0.174～10.9GHz,可重构阻带为5.1～5.95GHz,带宽比可高达62:1.     

Design of a Compact Hexagonal Monopole Antenna for Ultra—Wideband Applications

This paper presents two design compact hexagonal monopole antennas for ultra-wideband applications. The two antennas are fed by a single microstrip line . The Zeland IE3D version 12 is employed for analysis at the frequency band of 4 to 14 GHz which has approved as a commercial UWB band. The experimental and simulation results exhibit good agreement together for antenna 1. The proposed antenna1 is able to achieve an impedance bandwidth about 111%. The proposed antenna2 is able to achieve an impedance bandwidth about (31.58%) for lower frequency and (62.54%) for upper frequency bandwidth. A simulated frequency notched band ranging from 6.05 GHz to 7.33 GHz and a measured frequency notched band ranging from 6.22 GHz to 8.99 GHz are achieved and gives one narrow band of axial ratio (1.43%). The proposed antennas can be used in wireless ultra-wideband (UWB) communications.     

一种小型化双频天线的设计与分析

提出了一种小型化宽频带双频天线的设计。该天线由一个E形微带贴片和一个偶极子天线组合而成,产生高低2个频率,且低频段带宽可控。仿真的-10dB阻抗带宽分别为83MHz(2.4～2.485GHz)和812MHz(5.1～5.912GHz)。能够覆盖IEEE802.11b/g(2.4～2.483GHz)和IEEE802.11a(5.15～5.825GHz)工作频段,并对仿真结果进行了分析。同时给出的设计双频段宽带小型化天线的方法,可以对高低2个频段分开设计,对工程实践有一定的指导意义。     

Compact ultra-wideband antenna with tri-band notched characteristic

A compact ultra-wideband printed planar antenna with tri-band notched characteristic is presented. Two different types of slots are used to obtain tri-band notched characteristic. By using a U-slot defected ground structure, a notched band, 5?6 GHz for WLAN, is achieved. An H-shaped slot is etched on the radiating patch to obtain another two notched bands at 3.3?3.7 GHz for WiMAX and 7.2 GHz for some C-band satellite communication systems. The proposed antenna yields an impedance bandwidth of 3.1?10.6 GHz with VSWR , 2, except the notched bands. The antenna is successfully simulated and measured, showing tri-band notched characteristic can be obtained by using two different slots.     

Multi-Reconfigurable Band-Notched Coplanar Waveguide-Fed Slot Antenna

This paper proposes an antenna design concept to achieve a multi-reconfigurable band-notch antenna by using a set of microswitches. The proposed idea was proved by the design of the coplanar waveguide (CPW)-fed slot antenna. The sample design gives a wideband antenna the impedance bandwidth of which covers the frequency ranged from 1.9 GHz to 6.55 GHz. The antenna could be configured to work either in single-band mode or in one of the defined dual-band modes.     

Compact omnidirectional band-notch ultra-wideband antenna

A novel ultra-wideband printed monopole antenna with a band-notch characteristic and stable omnidirectional radiation is presented. The antenna design adopts a bevelled square patch as a monopole, a double-feed technique and a microstrip feeder embedded with an inverted U-shaped slot. Good agreement between simulation and experiment shows that the proposed antenna achieves an impedance bandwidth of 3.05-5.15 and 6.02-10.84 GHz for VSWRles2, a stable omnidirectional radiation and a low cross-polarisation level.