首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 672 毫秒
1.
设计了一种用共面波导馈电的双频天线,由切角的矩形和等腰梯形结构组合而成,使天线工作在2.32~2.57GHz和5.2~5.8 GHz频段。仿真和实测结果表明:采用共面波导馈电使天线辐射的远场方向图有更好的对称性,这种天线工作频段内S11参数小于-10 d B,电压驻波比小于1.5,相对工作带宽达到52%,可应用于无线局域网通信中。  相似文献   

2.
针对未来智能终端的体积小、多网融合特性,基于分形和仿生天线理论,借鉴自然界中铜钱草的圆环结构,采用分形结构和共面波导馈电技术,设计了一款结构新颖、多频段共面波导馈电小型天线。设计中采用HFSS软件进行建模仿真,通过对天线辐射体中圆环叶片个数和半径大小的变化、接地板形状及尺寸的优化,最终确定天线相关最佳参数,采用AV3629B矢量网络分析仪对天线实物进行性能测试。仿真和测试结果表明,该天线在覆盖的1.11~1.55 GHz、2.34~2.59 GHz、3.49~5.83 GHz频段内具有良好的辐射特性,可通用于TD-LTE专网宽带集群、卫星通信、4G/5G公众网、蓝牙、WLAN等通信系统。  相似文献   

3.
研究由中间低折射率材料和两边高折射率材料组成的硅槽光波导,光场可以被束缚在低折射率材料中.利用有限元方法模拟了硅槽光波导的色散特性,研究了群速度色散随光波导的高度、硅层宽度、槽宽度的变换规律,并通过进一步系统优化,在1 700~2 000 nm波长范围内获得平坦色散特性.  相似文献   

4.
传统的5层低折射率槽波导可以将光限制在纳米量级的中间低折射率层中.为了进一步减小波导的横向模式宽度,用金属层代替低折射率槽波导的最外层,构建了5层金属/高折射率/低折射率/高折射率/金属对称混合槽波导,利用解析的方法比较了混合槽波导结构与低折射率槽波导结构的光学限制能力.结果表明,通过用金属层替换低折射率槽波导的最外层,可以获得更强的光限制能力和更窄的模式.同时也对混合槽波导结构的传播损耗做了研究,发现混合槽波导有较低的传播损耗.  相似文献   

5.
将微带线/共面波导混合结构与螺旋型缺陷接地结构结合,设计了通带范围3.1~10.6GHz的超宽带带通滤波器,获得了双通带的滤波特性。采用仿真的方法讨论了缺陷接地结构的尺寸与传输特性的关系。结果表明,新型的双通带带通滤波器具有一定的实用价值。  相似文献   

6.
无刷双馈电机(BDFM)作为一种新型电机,兼有绕线式转子异步电机和同步电机的优良特性,尤其适合于变速恒频发电领域,通过分析无刷双馈电机的结构及工作原理,建立了基于转子速坐标系的d-q轴无刷双馈电机数学模型,根据所得的数学模型,对无刷双馈电机的各种运行方式进行了仿真分析,采用MATLAB/Simulink进行了计算机仿真研究,得出了各种运行方式下的仿真波形,仿真结果验证了数学模型的正确性和可行性,并得到了一些有益的结论.  相似文献   

7.
本文将W.K.B近似法拓宽到缓交参量条件下的计算、类比了量子力学中的结果,并以渐变折射率光波导和平面分层介质两种模型为例作了一些有益的探讨.关键词:W.K.B.近似法,缓变参量  相似文献   

8.
研究了光脉冲通过光子晶体线缺陷波导的透射特性.分析发现光子晶体线缺陷波导的透射行为与波导的几何尺寸有关.通过调制波导的几何结构可以获得较平坦的透射谱.另外发现耦合线缺陷所选择的点缺陷是影响线缺陷波导透射特性的重要因素,通过调节点缺陷的尺寸,缺陷间可以很完美的耦合并获得超平坦的杂质带.该分析结果为光子晶体线缺陷波导的设计提供重要参考.  相似文献   

9.
设计了一种多分支平面印刷天线,采用微带线馈电方式,其中微带线设计成T形,与辐射单元匹配.辐射单元由3个L形的金属面结构构成,其分别工作在2.4 GHz、3.5 GHz和5.4 GHz,可应用于无线局域网(WLAN)和全球微波互联接(WiMAX)系统.通过电磁仿真软件HFSS对这种天线进行设计,在WLAN应用频段上10 dB阻抗带宽分别为1 GHz (4.9~5.9 GHz)和310 MHz (2.24~2.55 GHz);在WiMAX应用频段上10 dB阻抗带宽380 MHz (3.3~3.68 GHz).实测结果表明,这种天线具有良好的远场辐射特性,其增益在2.5~4.7 dBi之间.  相似文献   

10.
采用具有紧凑尺寸特征的高阻抗表面蘑菇状电磁带隙结构(EBG)做为双面印刷偶极子天线的反射板,利用HFSS电磁仿真软件模拟对传统金属良导体(PEC)反射板结构以及EBG反射板结构双面印刷偶极子天线的主要参数进行了对比研究。研究表明:采用EBG结构后可降低传统天线的高度约55%,同时提高天线增益约1.9dB。  相似文献   

11.
A simple and compact ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed in this paper. The antenna is partially grounded so that the Q value is depressed and the impedance bandwidth is broadened. A small strip bar is loaded on each arm of the similar U-shaped radiator. The impedance bandwidth of the antenna overlap with IEEE 802.11a is rejected consequently. The geometry parameters of the antenna are investigated and optimized with HFSS. The measured bandwidth of the proposed antenna occupies about 7.89 GHz covering from 3.05 GHz to 10.94 GHz with expected notched band from 4.96 GHz to 5.98 GHz. A quasi-omnidirectional and quasi-symmetrical radiation pattern in the whole band is also obtained. As a result, a UWB wireless communication system can be simplified with the band-notched UWB antenna presented.  相似文献   

12.
This paper introduces the advances of ultra-wideband(UWB)and super-wideband(SWB)planar antennas based on the printed monopole,microstrip slot and other planar antenna designs in the last decade.A brief history of the ultra- wideband antennas is first provided.Several types of planar antennas for UWB systems with band-notched designs are reviewed.Special SWB planar antenna designs with the bandwidth ratio greater than 10:1 including metal-plate and printed monopole antennas and tapered slot antennas are presented and compared.  相似文献   

13.
This paper proposes a compact polarization microstrip antenna based on double-layer structure.The bandwidth of the whole antenna is widened by expanding the top and bottom layers respectively.After the design of antenna structure and adjustment of size,the proposed antenna can achieve both the left-and right-hand circular polarizations in 2.33 GHz-2.97 GHz.Measurement results indicate that the effective bandwidth is 640 MHz in S-band and the relative bandwidth can achieve 24% with 11 S less than 15 dB.  相似文献   

14.
A dual S shaped micro strip antenna with a realistic feed is proposed for generation of tilted beam radiation pattern pertaining for beam steering applications. To achieve this, four feeding points are located at a distance of 5.6 mm from the antenna centre. These feeding points when excited one by one generate four tilted beams in four different space quadrants, thus yielding a beam steerable antenna. Importantly, since the proposed antenna is symmetrical in the structure, all the four tilted beams have the same radiation pattern characteristics. A further enhancement of the antenna bandwidth is also achieved using 100-μm capacitive coupling between the feed and the antenna strip.  相似文献   

15.
给出了一种紧凑的可用于WUSB的新型带陷超宽带印刷单极子天线.天线由内嵌条带的U形环组成并采用部分接地技术,从而使天线具有带陷超宽带特性.实测结果表明该天线输入端驻波比小于2的绝对阻抗带宽为7.88GHz,覆盖了3.12~11GHz的频率范围,其中5.06~5.89GHz范围内具有带阻特性.讨论了各几何参数对天线性能的影响,同时获得了该天线相对稳定的、近似全向且对称的测试方向图.由于此种天线无需额外的带阻滤波器来隔离天线与其他通信系统的干扰,从而大大简化了WUSB系统的设计.  相似文献   

16.
用于通信的超宽带印刷天线   总被引:1,自引:1,他引:1  
1IntroductionUltra-wideband(UWB)microwave antennas are ofinterest for a variety of applications such as electroniccountermeasure,transient radars,mine detection,andunexploded ordnance(UXO)location and identifica-tion.In the early2002,the release of the UWB forcommercial communications by the Federal Communi-cation Commission(FCC,USA)sparked renewed in-terest in the subject of UWB antennas.Conventional UWB antennas such as log-periodic orspiral antennas exhibit good UWB characteristi…  相似文献   

17.
本文设计了一种应用于无线局域网的电磁带隙结构(EBG)的微带天线。通过在微带贴片天线的辐射单元周围加载蘑菇型EBG结构,使得天线的带宽、增益性能得到了显著改善。仿真结果表明,与普通贴片天线相比,加载EBG结构时天线带宽增加了6%,主辐射方向上增益增大了1.98dB。  相似文献   

18.
在综合分析了微带平面天线阵列馈电网络的两种传统馈电方式的基础上,提出了一种在微波工程应用中实际使用的一种新型馈电网络,提高学生理论知识与实践相结合的能力,更好的掌握最新技术发展。其新型馈电网络由一种左-右手混合微带传输线构成,可以获得高于传统并联馈电网络的天线阵列增益;同时,可以修正传统串联馈电网络的天线阵列辐射方向图的波束偏移,给出了一个工作频率为35GHz的2×2微带面阵的馈电网络设计案例,验证了其理论的正确性。  相似文献   

19.
A wideband cavity-backed slot antenna operated in the ultra-high frequency(UHF)band is introduced.The antenna has a compact structure and low profile with the size ratio of the ground plane to the slot only 1.6:1.The measured impedance bandwidth of VSWR≤3 achieves 85.3%,covering a frequency range from 390 MHz to 970 MHz.The measured gain is about 5.5~7.5 dB.  相似文献   

20.
The Fabry-Perot resonator (FPR) antenna has found wide applications in microwave and millimeter waves and recently attracted considerable interest, in this paper, a summary of planar and cylindrical structures, analytic models and research development is presented, and a comparison between these structures and analytic models is made, showing that such analytic models as the FP cavity mode, electromagnetic band gap (EBG) defect mode, transmission line mode, and leaky-wave mode are consistent when applied to analyze this type of resonator antenna. Some interesting topics under recent research, including dual or multi-band, improvement of gain bandwidth, low profile and beam control, are surveyed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号