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Ultrawideband Printed Elliptical Monopole Antennas 总被引:1,自引:0,他引:1
Parametric study of ultrawideband printed elliptical monopole antennas have been presented. Design curve for the length of the feed transmission line for various lower band edge frequencies has been generated. Variation of bandwidth with ellipticity ratio of these configurations has also been studied. Experiments have been performed to measure bandwidth and radiation patterns of these configurations, which tally well with simulated results. The elliptical configuration with ellipticity ratio of 1.1 gives ultrawide impedance bandwidth ratio of 12.4:1 as compared to 10.2:1 of the circular monopole antenna. This antenna introduces minimum ringing and distortion/dispersion of the pulse in time domain 相似文献
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双频贴片天线研究与设计 总被引:2,自引:0,他引:2
无线通信的发展对天线(尤其是贴片天线)的各项性能提出了新的要求。与此同时,双频天线的应用也愈为广泛。总结了贴片天线的主要双频解决方案,包括正交模、多贴片、电抗性加载以及空气缝隙双频贴片等方式,并提出了相应双频贴片天线的适用场合。最后,结合HFSS仿真设计了一个双频双贴片天线,讨论了该天线特性,并对双频天线未来的发展趋势进行了展望。 相似文献
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WLAN平面天线研究 总被引:1,自引:0,他引:1
对一种小型的平面倒F天线进行了研究,根据WLAN 802.11b/g无线通信的需求设计出一种工作于ISM 2.4 GHz频段的小型平面倒F天线。该天线面积小,约为13.5 mm×5.5 mm,能方便地集成在Cardbus卡上,降低射频前端的成本。天线的设计采用了Agilent的ADS2004仿真工具,并给出了该天线的测试方法以及测试结果。 相似文献
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近年来,自动识别方法在许多服务领域,诸如货物采购与分配、商业贸易、生产制造和物流等领域中,得到了快速地普及和推广。自动识别的任务和目的是提供关于个人、动物和商品的信息。自动识别系统克服了标签存储容量小和不能改写的缺点。自动识别系统在数据载体与一个所属阅读器之间进行非接触式传输。根据自动识别系统使用的能量和数据传输方法,我们把非接触式识别系统称为RFID 系统。RFID 系统是通过阅读器与标签之间的天线之间交换能量来读取数据的。常用于RFID 系统中的天线有偶极天线、Yaugi-Uda 天线、片状或微带天线和缝隙天线。 相似文献
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《Microwave Theory and Techniques》1977,25(6):470-472
Model experiments at 10-GHz band have been performed to obtain optimum structures of printed resonant antennas for monolithic GaAs Schottky-diode detectors in the submillimeter-wave region. Design charts for antenna structures, which are also useful for a thin-film metal-to-metal diode structure on a dielectric substrate, are presented. 相似文献
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相控阵天线是由相位来控制波束指向的阵列天线,大带宽、双极化等特性是相控阵天线的特点.L型馈电和孔径耦合贴片天线带宽可达20%,但是一致性差,并且隔离度不高.针对上述问题,文章分析、改进了一种H缝隙的贴片天线并将之应用于相控阵领域,计算和测试结果表明:该种形式的双极化贴片天线完全可以应用于低剖面且具有较大带宽的相控阵天线,具有较大的实际应用价值. 相似文献
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Design and Characterization of Purely Textile Patch Antennas 总被引:1,自引:0,他引:1
Locher I. Klemm M. Kirstein T. Trster G. 《Advanced Packaging, IEEE Transactions on》2006,29(4):777-788
In this paper, we present four purely textile patch antennas for Bluetooth applications in wearable computing using the frequency range around 2.4 GHz. The textile materials and the planar antenna shape provide a smooth integration into clothing while preserving the typical properties of textiles. The four antennas differ in the deployed materials and in the antenna polarization, but all of them feature a microstrip line as antenna feed. We have developed a manufacturing process that guarantees unaffected electrical behavior of the individual materials when composed to an antenna. Thus, the conductive textiles possess a sheet resistance of less than 1Omega/squarein order to keep losses at a minimum. The process also satisfies our requirements in terms of accuracy meeting the Bluetooth specifications. Our investigations not only characterize the performance of the antennas in planar shape, but also under defined bending conditions that resemble those of a worn garment. We show that the antennas can withstand clothing bends down to a radius of 37.5 mm without violating specifications 相似文献
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提出了一种带有寄生贴片的全向印刷天线。该天线采用平行双线串馈的方式,以印刷振子作为辐射单元,通过引入寄生贴片,有效地平衡了水平面各个方向的辐射强度,使得水平面不圆度小于0.5 dB,并且改善了阻抗特性,天线VSWR≤1.5 的带宽达到6.6%。 相似文献
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This paper presents the design, simulation, and measurements of two low-cost broadband circularly polarized (CP) printed antennas: an element and an array at 2 GHz. To realize the broadband circularly polarized antenna element, a circular microstrip patch is electromagnetically coupled by crossed slots cut in the ground plane, which is fed by an L-shaped microstrip feed. Two orthogonal modes in the patch are excited by using the crossed slots, and a single L-shaped feed provides a 90deg phase shift between two orthogonal slots. The antenna element achieves a 9.6% bandwidth for an axial ratio (AR) below 3 dB and a voltage standing wave ratio (VSWR) below 1.5. To further improve the performance, a sequentially rotated feed network is designed for a 2 times 2 array. The axial ratio value of the array is below 3 dB within a 27.2% bandwidth, from 1.75 GHz to 2.3 GHz. The return loss is above 10 dB within a 41% bandwidth, from 1.62 GHz to 2.45 GHz. Details of the proposed antenna element and the array design are described, and both the simulation and the experimental results are presented and discussed. 相似文献
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低RCS栅格微带天线研究 总被引:1,自引:0,他引:1
研究了栅格微带天线在微带天线RCS减缩中的应用。分析了栅格线宽度、栅格线间距、栅格化方式等参数对天线的谐振频率、增益的影响。设计了一副具有低RCS特性的栅格微带天线,与谐振在同频率的微带贴片天线相比,天线的增益仅降低0. 6dBi,而天线在2~10GHz频带内的平均RCS降低4dBsm。 相似文献
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《Antennas and Propagation, IEEE Transactions on》2009,57(6):1612-1617
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Kanda M. Chang D.C. Greenlee D.H. 《Electromagnetic Compatibility, IEEE Transactions on》1985,(4):212-220
The fabrication of various iris-fed millimeter-wave rectangular microstrip patch antennas is described. A mathematical model is proposed to describe the iris-fed antenna. An iris having 15 percent of the area of the patch is used to couple energy into the antenna. Resonance of the antenna is observed to be insensitive to the size of the iris for irises up to 115 percent of the size of the patch. A study is also made of the coupling to the antenna as a function of position of the iris with respect to the transverse plane of the waveguide, the iris always being centered with respect to the patch. In general, the antenna has a VSWR in the waveguide feed of roughly 5:1 at resonance, except for the fully open waveguide which gives rise to a VSWR of 2.9:1 at resonance. Far-field antenna power patterns are observed to be quite broad with H-plane beamwidths about 130°. Maximum antenna gain observed was 4.5 dB relative to an isotropic source (dBi), with 2 dBi typical. An initial study is made of the microstrip patch antenna fed from a longitudinal waveguide wall. Results indicate that this feed structure is likely to prove valuable for microstrip patch antennas, with coupling at least as good as for the transverse-fed patch, added to the possibility of feeding multiple patches from a single waveguide. 相似文献
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Future generation local communication systems will need to employ THz frequency bands capable of transferring sizable amounts of data. Current THz technology via electrical excitation is limited by the upper limits of device cutoff frequencies and by the lower limits of optical transitions in quantum confined structures. Current metallic THz antennas require high power to overcome scattering losses and tend to have low antenna efficiency. It is shown here via calculation and simulation that graphene can sustain electromagnetic propagation at THz frequencies via engineering the intra‐ and interband contributions to the dynamical conductivity to produce a variable surface impedance microstrip antenna with a several hundred GHz bandwidth. The optimization of a circular graphene microstrip patch antenna on silicon with an optimized return loss of ?26 dB, a ?10 dB bandwidth of 504 GHz, and an antenna efficiency of ?3.4 dB operating at a frequency of 2 THz is reported. An improved antenna efficiency of ?0.36 dB can be found at 3.5 THz but is accompanied by a lower bandwidth of about 200 GHz. Such large bandwidths and antenna efficiencies offer significant hope for graphene‐based flexible directional antennas that can be employed for future THz local device‐to‐device communications. 相似文献
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A Printed Circuit Balun for Use with Spiral Antennas 总被引:4,自引:0,他引:4
《Microwave Theory and Techniques》1960,8(3):319-325
A novel printed circuit balun is described which is particularly well suited to applications where space is at a premium. The design utilizes unshielded strip transmission line, but is readily adaptable to all of the common printed circuit transmission line techniques. When the balun is housed within the cavity of a spiral antenna, boresight error is virtually eliminated, ellipticity ratios of less than 2 db are maintained over an azimuth angle greater than /spl plusmn/ 60/spl deg/, and the input standing-wave ratio is less than 2:1 over an octave frequency range. Experimental results are given and additional applications are described. 相似文献
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文中研究了在时间上采用5级4阶差分、空间上采用4阶差分的高阶辛时域有限差9(SFDTD)数值方法。给出其三维差分公式.将吸收边界条件应用于微带天线的计算中,计算了微带贴片天线的回波损耗及输入阻抗等.计算结果证明,该方法的精确性和正确性. 相似文献
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Yue-Qun Zhou Feng-Chao Yu Ting-Gen Shen Pei-Lai Ji Ge J. Jian-Feng Gen Jing Len 《Photonics Technology Letters, IEEE》2008,20(20):1685-1687