抑制两个偶极子天线电磁耦合的新方法

文中通过分析带缝隙的有限接地导电平面对其上偶极子天线耦合度的影响.提出采用具有双缝隙有限接地导电平面,抑制其上两偶极子天线间电磁耦合的新方法.数值分析结果表明,缝隙长度约为相应发射天线工作波长的1/2时,与单缝隙有限接地导电平面相比较,双缝隙有限接地导电平面抑制其上两偶极子天线间电磁耦合效果较优.     

蜂窝网移动通信用基地台天线

采用物理光学法(POM)求解有限尺寸矩形反射板上对称偶极子的辐射特性,将若干个偶极子排列起来,得到蜂窝网布局通信的特殊方向图,即H面方向图半功率波束宽度为65°的平板阵列天线。分析了馈电网络的匹配特性,给出了依据本文的计算结果制做的实用天线性能测试结果,并且理论和实验吻合较好。     

大功率短波转动天线折合偶极子的应用及调配

本文通过对大功率短波转动折合偶极子阻抗的分析和实际测量,提出了利用自动调谐单元对天线进行全频段、全组态阻抗调配,以实现良好的宽带性能,可有效提高该类型天线的设计和使用效率。     

用于生物医疗的共面波导馈电双频植入式天线

设计了一款用于生物医疗的微小紧凑型共面波导馈电双频植入式天线。该天线工作于工业、科学和医疗(Industrial Scientific Medical, ISM)低频段(433~434.8 MHz)及无线医疗遥测服务(Wireless Medical Telemetry Service, WMTS)频段(1.395~1.40 GHz),尺寸仅为10 mm×10 mm×1.27 mm。天线采用共面波导馈电结构,易于和其它结构集成,采用高介电常数介质基板和折合蜿蜒类偶极子结构使天线尺寸得以有效缩小。在满足SAR(Specific Absorption Rate,比吸收率)值标准的前提下,采用U形接地板,以获得较高的增益,在两个频段内谐振频率处的最高增益分别为-32.23 dBi和-20.63 dBi,提升了天线性能。最后,基于仿真结果制作天线实物并进行了测试,实测数据与仿真结果吻合较好。研究成果可为植入式天线研制与应用提供重要参考。     

X波段宽带微带偶极子天线

文中提出一种X波段宽带微带偶极子天线。该天线在偶极子单元的基础上,采用了一个短路探针补偿馈电分布电容,同时增加了一个加载寄生贴片,有效的展宽了带宽。天线的总体尺寸为16mm×24mm,结构紧凑,易于加工和集成,适用于宽带宽角扫描的阵列天线。文中给出了天线的设计参数及不同参数对天线性能的影响。     

结构紧凑型宽带低副瓣阵列天线

为了满足系统对阵列天线宽带、低副瓣的要求,设计了一款工作在X和Ku波段的结构紧凑型宽带低副瓣阵列天线,相对带宽为54.5%,副瓣电平在-30 dB以下,天线纵向尺寸为4.5λg。阵列天线采用带状线加权馈电网络和宽带带状线偶极子天线一体化设计,偶极子天线用短路探针对馈电分布电容进行补偿并加载寄生贴片,有效展宽了带宽;馈电网络通过拓扑结构设计获得各功分节点最佳功率比值,对各功分节点位置合理布局缩减馈电网络纵向尺寸。在微波暗室利用近场测试系统对阵列天线实物进行测试,验证了仿真结果。     

新型弯折偶极子RFID天线的小型化分析与设计

标签天线是RFID系统的关键部件,UHF频段RFID系统多采用偶极子天线及其变型型式,由于受RFID卡尺寸的限制,天线的小型化成为制约RFID技术发展的瓶颈之一.文章创新性地设计了一种最大理论读取距离为5.6m的新型弯折线偶极子RFID标签天线,尺寸仅为22.5mm×30.5mm×1.6mm,小于目前已出现的标签天线,其方向性及带宽性能良好,阻抗调节臂的引入使得天线与标签芯片的匹配变得更加方便.采用无通孔和短路结构的单层印刷电路板加工天线,其测试结果与仿真结果具有良好的一致性.     

弯折线偶极子天线谐振特性的研究

本文研究了由矩形弯折线构成的偶极子天线的谐振特性,分析了弯折线偶极子天线的弯折次数、矩形弯折的高度以及弯折角度等参数对天线谐振特性的影响。结果表明,弯折线偶极子天线的参数改变对天线谐振特性有较强的调节作用,适当的改变天线的参数可以获得较好的天线尺寸缩减特性,适合RFID标签天线的应用。     

超宽频带小尺寸对数周期偶极子天线设计分析

文章研究了超宽频带对数周期偶极子天线(LPDA)的结构,对15～110MHz超宽频带对数周期偶极子天线的尺寸参数进行了设计,根据设计分析,对于超短波波段超宽频带对数周期偶极子存在的天线纵向尺寸较大的问题对该天线纵向尺寸进行了设计创新,从而使天线在包括工作带宽、增益、方向图等电特性参数不变差的前提下使纵向尺寸设计值从29...     

一种超介质单元加载的电小天线

根据等效介电常数为负(epsilon-negative,ENG)的超介质层加载偶极子天线可增强辐射效率的原理,提出一种新型电小天线。采用"门"型单元结构对中心频率为400MHz的电单极子加载,在提高天线辐射效率的同时极大地减小天线尺寸。测试结果表明,"门"型电小天线的增益与传统0.25λ单极子天线相当,比同尺寸单极子天线提高8dB,实际天线尺寸仅为0.08λ。     

宽频化与小型化微带天线的研究与设计

以微带天线技术为基础,以工作于ISM频段微带贴片天线为例,采用Ansoft公司的电磁仿真软件HFSS,对不同介电常数、不同介质板厚度、矩形贴片开槽开缝、加载寄生贴片等微带贴片天线进行了仿真。通过数值分析,阐述了介电常数、基板厚度、贴片开槽、寄生贴片等因素对微带贴片天线尺寸和频带宽度的影响。仿真结果表明,设计能够实现两种性能的天线结果,天线的宽度达到36%。天线的尺寸缩小了34.2%。     

一种新型小型化微带天线的分析与设计

针对传统微带天线低频端尺寸较大的缺点,设计了一种新型微带天线结构,即通过采用在传统微带天线贴片下方挖出凹槽,将辐射板放入凹槽中的办法,设计了一副小型化微带天线。与普通微带天线相比,新型天线谐振频率降低了870MHz,阻抗带宽从原来的170MHz增至560MHz,且天线在整个工作频段内具有良好辐射特性,从而验证了该设计方案的正确性。     

梯形接地板结构超宽带天线设计

在圆形单极天线的基础上进行改进设计了一款梯形接地板结构的超宽带单极天线。根据接地板电流的分布强弱,削去矩形接地板两端对电流影响较小的三角形形状部分,构成梯形接地板。经过仿真优化实验结果表明,该天线电压驻波比VSWR2的阻抗带宽为3.1~17 GHz,工作频段内具有全向辐射特性,且天线只有20 mm×22 mm×1.6 mm,结构简单,适合超宽带无线通信系统的要求。     

Ultra‐small Marker Beacon Antenna with a Wide Frequency Tuneable Capacitive Plate

In this paper, an ultra‐small marker beacon antenna operated in the VHF‐band is proposed. This antenna has a modified linear IFA structure with a lumped capacitor and a capacitive plate for frequency tuning and impedance matching. The capacitive plate is directly connected to the end of a linear radiator and is separated from the antenna ground by 1 mm. The main operating frequency is mainly controlled by the size and dielectric constant of the capacitive plate. The lumped capacitor is useful for fine frequency tuning. Using the proposed structure, an ultra‐small marker beacon antenna can be realized with a length of 0.04 λ₀.     

基于光子晶体的小型微带天线的分析与设计

针对传统微带天线低频端尺寸较大的缺点,设计了一种基于光子晶体的新型微带天线结构,即通过采用在传统微带天线贴片下方挖出凹槽,将辐射板放入凹槽中,并在微带天线的介质基板中引入高度不同的周期性圆柱空气隙光子带隙（PBG）结构的设计方案。采用基于有限元方法的电磁仿真软件HFSS 10．0对所设计的天线进行了仿真。仿真结果表明,当回波损耗小于-10．0dB时,天线的工作频段分别为2．40GHz～2．51GHz和3．54GHz～3．62GHz,且天线在这两个频段内具有良好的辐射特性。与传统的微带天线相比,所设计的天线后向辐射明显降低,且其整体尺寸减少了59．19％,从而验证了这种设计方案的有效性。     

对角馈电的SIW单腔体双极化领结形缝隙天线

多极化天线能够有效利用电磁波的空间维度,使无线通信或雷达系统容量得到很大提高。从对角馈电的基片集成波导腔体的场分布出发,分析其传输模式。通过在腔体表面设置正交缝隙,可以实现两种相互垂直的极化方式。在分析正交矩形缝隙和领结形缝隙的尺寸对天线性能影响的基础上,获取了TE120模谐振频率的经验计算公式,从而设计了两种双极化天线并比较了两者的工作性能。测试和分析结果表明,双极化领结形缝隙天线具有更大的带宽和更小的缝隙尺寸,测试的工作带宽为200 MHz,天线增益为5.2 dBi,具有广阔的应用前景。     

Internal Ultrawideband Monopole Antenna for Wireless USB Dongle Applications

A novel, ultrawideband (UWB) monopole antenna suitable to be mounted on the printed circuit board (PCB) of a wireless, universal, serial-bus (USB) dongle as an internal antenna is presented. The proposed antenna in the study is a U-shaped, metal-plate monopole antenna, easily fabricated from bending a simple metal plate onto a foam base of a compact size of 6times11times20 mm³. The antenna mainly comprises a pair of wide-ended radiating arms and a bevel-feed transition. When the antenna is mounted at the top portion of the PCB, one end of the radiating arm is also short-circuited to the system ground plane. With the proposed antenna structure, which can provide a very wide operating bandwidth of larger than 7.6 GHz, the antenna impedance bandwidth can easily cover the 3.1-10.6 GHz UWB band. Details of the antenna design are described, and experimental results of the constructed prototypes are presented and discussed     

CLIP antenna for wireless bluetooth applications

In this paper, a novel design for a coplanar waveguide antenna is developed that consists of two U-shaped slots. The antenna is named CLIP. The antenna was designed for a central frequency of 2.4 GHz, with an input impedance of 50 /spl Omega/. The antenna dimensions represent a 72% size reduction compared to a conventional microstrip rectangular-patch antenna. The measured antenna bandwidth was about 11%, while its gain was about 17 dB. These values are fairly acceptable in all wireless communication systems. The antenna configuration has a bidirectional radiation pattern, while a unidirectional radiation pattern was achieved by using a /spl lambda//sub 0//4 reflector with a metal plate. A 2/spl times/2 multi-element sub array was implemented to widen the application area. The mutual coupling between adjacent elements was low. Orthogonal-plane coupling between adjacent elements was introduced to increase the reduction in the mutual coupling. The mutual coupling level was reduced to less than -23 dB in all coupling planes. The CLIP antenna element and arrays were fabricated. Experimental measurements showed very good performance, which agreed well with simulation results.     

Compact patch antenna mountable above conducting plate for wlan operation

A compact patch antenna suitable for mounting above a conducting plate for WLAN operation in the 2.4 GHz band is presented. It is demonstrated that, by introducing a supporting metal plate connected to the antenna ground below, the proposed antenna in free space can easily be mounted at the corner of a conducting plate of various dimensions without rapidly deteriorating the antenna bandwidth. With a compact size of 20times20times6 mm, the antenna can be placed very close to a conducting plate of side length varied from 20 to 200 mm for application in a PC peripheral device