共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
新型集成超宽带开槽天线的研制及其应用 总被引:9,自引:1,他引:9
研制出一种用于超宽带短脉宽射和接收的新型集成超宽带槽天线,该天线采用共面波导到槽线的宽带过渡方式馈电,实验结果显示了其高保真的宽带特性及高增益高效益特性。利用所研制的UWB天线建立起超宽超带雷达实验系统,测量几种简单目标特性及涂层目标特性,证明了该种天线可用作实际的UWBR天线。 相似文献
3.
4.
WANGXiang-hui JIANGYang-sheng WANGWen-bing 《半导体光子学与技术》2005,11(1):65-68
A new ultra-wide-band(UWB) horn antenna based on the nonradiative dielectric waveguide (NRD-guide) was proposed to solve the problem of UWB antennas, TEM horns for example, generally suffer from large side leakage. The rule of the theoretical selection of its parameters, if NRD-guide is used as the UWB antennas, is studied firstly, then the radiation characteristics for an open-ended NRD-guide are calculated by FDTD (finite-difference time-domain) method. 相似文献
5.
用于超短脉冲辐射和接收的新型平面集成天线辐射元 总被引:1,自引:0,他引:1
研制出一种用于超宽带短脉冲辐射和接收的新型平面集成超宽带(UWB)天线辐射元,该天线辐射元采用共面波导到槽线的宽带过滤方式馈电,超短脉冲辐射和接收的实验结果显示了其高保真宽带及高增益、高效率的特性。 相似文献
6.
小型平面超宽带天线的研究进展 总被引:5,自引:0,他引:5
对小型平面超宽带(UWB)天线的研究现状进行了分析总结.首先介绍超宽带无线通信的技术背景,描述了超宽带天线的几种常见定义.然后分别对小型超宽带印刷单极子天线的设计、小型超宽带缝隙天线的设计、具有陷波功能的小型超宽带天线的设计进行了详细的评论,并讨论了超宽带天线的性能评价方法.最后展望了小型平面超宽带天线的未来研究方向. 相似文献
7.
8.
Venkatarayalu N.V. Chi-Chih Chen Teixeira F.L. Lee R. 《Antennas and Propagation, IEEE Transactions on》2004,52(5):1318-1323
A detailed characterization of the input impedance of ultrawide-band (UWB) dielectric horn antennas is presented using the finite-difference time-domain (FDTD) technique. The FDTD model is first validated by computing the characteristic impedance of two conical plate transmission lines (including planar bow-tie antennas) and comparing the results to analytical solutions. The FDTD model is next used to calculate the surge impedance of dielectric horn antennas using the conical plates as launchers. Design curves of the surge impedance for different choices of geometries and dielectric loadings are provided. The modeled antennas are particularly attractive for applications such as UWB ground penetrating radars (GPR) applications. 相似文献
9.
对陷波特性超宽带(UWB)天线的研究现状进行了分析总结.介绍了陷波特性超宽带天线的技术背景,分别对近年来陷波功能超宽带天线的设计进行了详细的评论,最后展望了陷波特性超宽带天线的未来发展方向. 相似文献
10.
Wang Xianghui Jiang Yangsheng Wan Wenbing 《Journal of Infrared, Millimeter and Terahertz Waves》2004,25(9):1325-1335
A successful design for a UWB (ultra-wideband antennas) antenna based on NRD-guide (nonradiative dielectric waveguide) with small side-leakage is presented. The rule of the theoretical selection of its parameters, if NRD-guide is used as the UWB antennas, is studied firstly, then the temporal propagation characteristics of the NRD-guide and the radiation characteristics for an tapered open-ended NRD-guide are calculated by FDTD (finite-difference time-domain) method. 相似文献
11.
A Time/Frequency Model of Ultrawideband Antennas 总被引:1,自引:0,他引:1
Duroc Y. Tan-Phu Vuong Tedjini S. 《Antennas and Propagation, IEEE Transactions on》2007,55(8):2342-2350
A new approach to model ultrawideband (UWB) antennas is proposed. A mathematical analysis of transmission through an UWB system in terms of transfer function and impulse response is proposed. The analysis allows the separation of the transmitting and receiving antenna characteristics, using a consistent treatment with other UWB and earlier narrowband analysis techniques. A parametric modeling is added to provide efficient directional time-frequency models of UWB antennas. The technique is demonstrated through simulation and experiment. 相似文献
12.
Li-Chun Wang Wei-Cheng Liu Kuan-Jiin Shieh 《Wireless Communications, IEEE Transactions on》2005,4(6):2738-2750
This paper presents an analytical expression for the signal-to-noise ratio (SNR) of the pulse position modulated (PPM) signal in an ultrawideband (UWB) channel with multiple transmit and receive antennas. A generalized fading channel model that can capture the cluster property and the highly dense multipath effect of the UWB channel is considered. Through simulations, it is demonstrated that the derived analytical model can accurately estimate the mean and variance properties of the pulse-based UWB signals in a frequency-selective fading channel. Furthermore, the authors investigate to what extent the performance of the PPM-based UWB system can be further enhanced by exploiting the advantage of multiple transmit antennas or receive antennas. Numerical results show that using multiple transmit antennas in the UWB channel can improve the system performance in the manner of reducing signal variations. However, because of already possessing rich diversity inherently in the UWB channel, using multiple transmit antennas does not provide diversity gain in the strict sense [i.e., improving the slope of bit error rate (BER) versus SNR] but can possibly reduce the required fingers of the RAKE receiver for the UWB channel. Furthermore, because multiple receive antennas can provide higher antenna array combining gain, the multiple receive antennas technique can be used to improve the coverage performance for the UWB system, which is crucial for a UWB system due to the low transmission power operation. 相似文献
13.
A mixed model of two-dimensional (2D) genetic algorithm (GA) and finite-difference time-domain (FDTD) is applied to the automatic design of band-notched ultra-wideband (UWB) planar antennas of a finite size. The geometric shape of a band-notched UWB antenna is constructed by the method. Measured return losses, radiation patterns and gains are in good agreement with the designed ones. These results illustrate that the method is valid and a new band- notched UWB antenna is designed successfully in the designated small size. 相似文献
14.
《Antennas and Propagation, IEEE Transactions on》2008,56(9):2894-2902
15.
Kramer B. A. Chen C.-C. Lee M. Volakis J. L. 《Antennas and Propagation Magazine, IEEE》2009,51(4):57-69
Fundamental physical limitations restrict an antenna's performance based on its electrical size. These fundamental limits are of the utmost importance, since the minimum size needed to achieve a particular figure of merit can be determined from them. In this paper, the physical limitations of antennas are reviewed in general, with particular emphasis on impedance matching as it relates to ultra-wideband (UWB) antennas (high-pass response). Additionally, the use of antenna miniaturization techniques to approach these limits is discussed. Using a spiral antenna as an example, guidelines are presented for miniaturizing UWB antennas. 相似文献
16.
《Geoscience and Remote Sensing, IEEE Transactions on》2009,47(4):1179-1186
17.
A compact antenna for ultrawide-band applications 总被引:1,自引:0,他引:1
A novel compact and ultrawide-band (UWB) antenna is presented in this paper. The basis for achieving such an UWB operation is through proper magnetic coupling of two adjacent sectorial loop antennas in a symmetrical arrangement. A large number of coupled sectorial loop antennas (CSLA) with different geometrical parameters are fabricated and their measured responses are used to experimentally optimize the geometrical parameters of the antenna for achieving the maximum bandwidth. Through this optimization process an antenna with a VSWR of lower than 2.2 (S/sub 11/<-8.5 dB) across an 8.5:1 frequency range is designed. The maximum dimension of this antenna is smaller than 0.37/spl lambda//sub 0/ at the lowest frequency of operation and provides an excellent polarization purity. Furthermore, the antenna exhibits a relatively consistent radiation pattern. Modified versions of the CSLA are also designed to reduce the overall metallic surface and weight of the antenna while maintaining its wide-band characteristics. This allows modifying its dimensions to design low frequency light-weight UWB antennas. 相似文献
18.
Tzyh-Ghuang Ma Chao-Hsiung Tseng 《Antennas and Propagation, IEEE Transactions on》2006,54(4):1105-1110
In this paper, we present a new coplanar waveguide-fed tapered ring slot antenna for ultrawideband (UWB) applications. This antenna consists of a 50 /spl Omega/ coplanar waveguide feeding line, wideband coplanar waveguide-to-slotline transition, and a pair of curved radiating slots. The impedance bandwidth with VSWR<2 is from 3.1 GHz to more than 12 GHz. The actual operating bandwidth is, however, limited by the distortion of radiation patterns. Such pattern distortion can be attributed to the antenna mode transition and is investigated in this paper with the help of the radiation patterns in the traditional sense as well as a dimensionless normalized antenna transfer function. By suitably allocating such mode-transition phenomenon to the notched band in a UWB radio, we demonstrate that antennas with desirable radiation characteristics in both UWB low and high bands can be readily achieved. The system responses of a transceiving antenna system in free space are addressed as well. 相似文献
19.
Do-Hoon Kwon 《Antennas and Propagation, IEEE Transactions on》2006,54(8):2208-2215
Pulse-preserving capabilities of ultrawideband (UWB) antennas, which are measured in terms of two parameters-the fidelity factor and the pulse width stretch ratio, are analyzed with respect to variations of the antenna gain and the group delay of the radiated field. With the degrees of the gain and the group delay variations quantified by their respective standard deviations from constant values, Monte-Carlo simulations are performed to evaluate the effect of different gain and group delay functions using randomly generated Gaussian profiles. The means and the standard variations of the two performance parameter distributions are monitored and their two-dimensional profiles are specifically obtained for UWB antennas operating in 3.1-10.6 GHz. The analysis also demonstrates the use of the fidelity factor and the pulse width stretch ratio as useful characterizing parameters for UWB antennas. 相似文献
20.
在现代通信技术中,为了实现通信保密、排除干扰、提高通信效率等,超宽带系统得到了大力发展,然而,在一定程度上却受制于系统中超宽带天线的阻抗带宽。详细介绍了展宽天线阻抗带宽的4种方法,包括渐变阻抗方法、分形几何方法、微带天线开槽方法和非频变结构方法,其中分形几何方法由于其几何结构的自相似性使得其贴片电流分布具有自相似性,从而导致天线的多频点谐振,有效拓展了天线带宽。上述4种天线尽管作用原理互不相同,但在超宽带天线的工程应用中,研究者可将这些方法单独或同时应用于天线结构设计,使得天线既能保持良好的方向性和增益等性能,又能获得较大带宽。 相似文献