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This paper analyzes the achievable sum‐rate of correlated two‐antenna multiple‐input multiple‐output (MIMO) uplink channels. Most of previous works have considered the case when a single user has multiple transmit antennas (i.e. multi‐antenna single‐user scenario). This paper considers the case when two‐antenna MIMO uplink channels comprise two users with a single transmit antenna (i.e. single‐antenna two‐user scenario). The analytic and simulation results show that the achievable sum‐rate of correlated single‐antenna two‐user MIMO uplink channels highly depends on the angle difference between the receive correlation coefficients of two users. It is also shown that the achievable sum‐rate of correlated single‐antenna two‐user MIMO uplink channels is larger than that of correlated two‐antenna single‐user MIMO uplink channels and can even be larger than that of independent and identically distributed Rayleigh two‐antenna MIMO uplink channels. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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根据天线远场测试理论,结合应用实例,分析了微波暗室和斜天线测试场作为天线远场测试场的适应性。对从
微波暗室和斜天线测试场得到的双脊喇叭天线远场方向图及相关数据进行了分析,总结出两种天线测试场对天线远场测
试影响的特点和规律,并对实际应用提出了指导性建议。 相似文献
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Kin-Lu Wong Tzung-Wern Chiou 《Antennas and Propagation, IEEE Transactions on》2002,50(3):346-351
Designs of broadband dual-polarized patch antennas fed by promising feed structures of a capacitively coupled feed and a slot-coupled feed (antenna A), two capacitively coupled feeds of a 180° phase shift and a slot-coupled feed (antenna B), and two capacitively coupled feeds of a 180° phase shift and two slot-coupled feeds (antenna C) are proposed and experimentally studied. The first two feed designs are for the excitation of a single-element broadband patch antenna, while the last design is for a two-element broadband patch antenna. These proposed patch antennas have a thick air substrate, and the 10 dB return-loss impedance bandwidths obtained for the two polarizations are all greater than 13%. High isolation (<-30 dB for antenna A, <-32 dB for antenna B, <-35 dB for antenna C) between the two feeding ports for the entire impedance bandwidth of the proposed antennas can be obtained. Also, improved cross-polarization levels (>20 dB) in both E and H plane patterns for the two polarizations of antennas B and C are achieved 相似文献
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设计并仿真了一种基于H 形缝隙耦合馈电,工作在u K 波段的微带双极化天线,并进行了4 单元平面组阵。4
单元阵实现的指标:驻波小于2 的相对带宽达到8.2%,双极化端口隔离度达-32dB,交叉极化达-23.5dB,方向图前后比
达-28dB,增益达到15dB,3dB 增益带宽达23.2%,并且两种极化下天线方向图有较好的一致性。天线采用多层结构,减
小了天线尺寸,并且两组馈电在不同夹层的设计使得进一步组阵变得便利,适应了双极化合成孔径雷达及抗多径干扰高
的移动通信系统的需要。 相似文献
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"动中通"天线极化轴稳定性研究 总被引:1,自引:0,他引:1
为克服动中通两轴稳定造成的极化失配问题,在对卫星天线波束特性和波束稳定实质进行分析的基础上,建立"动中通"卫星天线极化轴稳定的通用性模型。基于此模型对天线极化轴稳定性进行了仿真,定量地证明了极化轴稳定的必要性。最后根据所推模型给出了两种极化稳定方案。 相似文献
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A two-port wing-shaped antenna has been designed for small mobile devices. The proposed antenna system is composed of two wing-shaped antenna elements with different wing size. The two wing-shaped elements make it possible for a mobile device to cover all current and next mobile services such as GSM 850/900, DCS, PCS, Mobile WiMax (Wibro), and 802.11a/b/n. Moreover, the excellent isolation between the two antenna elements is achieved by designing the wings with opposite current flow. The proposed antenna system has potential for achieving any frequency bands in commercial use. 相似文献
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分形天线的特性分析及其在MIMO天线中的应用 总被引:2,自引:0,他引:2
分形最基本的特征是自相似特性与分数维,可以很好地应用于设计天线.与传统天线相比,在性能保持相近的情况下,分形天线表现出两个突出的优势:减小天线尺寸和使天线在多频带下工作.文中以Koch天线、分形树天线和分形环天线为例,说明了分形天线减小天线尺寸的优势;以Sierpinski基垫天线为例,说明了分形天线增加天线工作频带的优势.还对Minkowski分形天线阵列进行了分析,表明作为天线阵列单元的分形天线,可以提高天线阵的辐射特性.文中提出了将Minkowski分形天线应用于多输入输出(MIMO)天线中. 相似文献
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Dual-band planar inverted F antenna for GSM/DCS mobile phones 总被引:2,自引:0,他引:2
Shih-Huang Yeh Kin-Lu Wong Tzung-Wern Chiou Shyh-Tirng Fang 《Antennas and Propagation, IEEE Transactions on》2003,51(5):1124-1126
A compact dual-band planar inverted F antenna suitable for the application as a global system for mobile communication/digital communication system (GSM/DCS) dual-band mobile phone internal antenna is proposed and implemented. The proposed antenna has three resonant elements, two meandered metallic strips of slightly different lengths and one nearly-rectangular patch, which are printed on a supporting FR4 substrate and arranged in a compact configuration. These three resonant elements share a common shorting pin, and for the GSM (890-960 MHz) operation, the proposed antenna is operated with the two meandered strips both resonated as a quarter-wavelength structure, leading to a wide bandwidth formed by two resonant modes. For the upper band of the proposed antenna, three resonant modes are generated, two from the second higher-order modes of the two meandered strips and one from the nearly-rectangular patch, leading to a wide bandwidth covering the DCS band (1710-1880 MHz). The antenna design and experimental results are presented. 相似文献
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Ultrawideband Double Rhombus Antenna With Stable Radiation Patterns for Phased Array Applications 总被引:1,自引:0,他引:1
A broadband microstrip-fed printed antenna is proposed for phased antenna array systems. The antenna consists of two parallel-modified dipoles of different lengths. The regular dipole shape is modified to a quasi-rhombus shape by adding two triangular patches. Using two dipoles helps maintain stable radiation patterns close to their resonance frequencies. A modified array configuration is proposed to further enhance the antenna radiation characteristics and usable bandwidth. Scanning capabilities are studied for a four-element array. The proposed antenna provides endfire radiation patterns with high gain, high front-to-back (F-to-B) ratio, low cross-polarization level, wide beamwidth, and wide scanning angles in a wide bandwidth of 103% 相似文献
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This paper researched a kind of dual-polarized and cylindrical waveguide antenna fed by two L-shaped probes at the antenna bottom. The designed antenna was composed of two orthogonal L-shaped coaxial probes and a cylindrical waveguide cavity. The two orthogonal field structures were excited and the dual-polarized radiation mode was formed. The feeding cables of two polarization ports went through the bottom of the cylindrical cavity and were connected with the microwave adaptors. The bottom feeding structure was suitable to constitute a planar antenna array. The electromagnetic simulation and optimization design of the proposed antenna were carried out by using the full wave electromagnetic simulation technique, and the simulation results showed that the isolation between two polarization ports were more than 20 dB within the frequency range of 4.8–5.4 GHz. At the center frequency, the cross-polarization levels of radiation pattern were lower than −21 dB at the boresights and the beam width of radiation patterns at E-plane and H-plane were more than 70° for two polarization ports. The designed antenna in this paper was fabricated and measured. The measurement results indicated that the designed antenna achieved anticipated radiation performances and design effectiveness of the dual-polarized antenna in this paper was proved. The dual-polarized and cylindrical waveguide antenna is suitable for some application fields such as dual-polarized array radar. The research results in this paper can provide a technical basis for the practical engineering application. 相似文献
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A new multiband and broadband antenna based on the traditional fractal equilateral Parany monopole is presented. In general, Parany and Sierpinski monopoles are resonant, log-periodic and multi-band antennas. For example, a traditional two-stage Parany monopole antenna provides three bandwidths. In this Letter, the input impedance behaviour of this antenna is improved by adding two conductor triangles to a traditional two-stage Parany monopole and eliminating two connections between the conductor triangles that shape such an antenna. For VSWR<3, the resultant fractal two-stage Parany monopole antenna with triangular complements shows bandwidth improvements compared to the traditional two-stage Parany monopole antenna. Good agreement between simulated and measured results was observed. 相似文献
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在对相控阵雷达系统建模仿真工作中,相控阵天线建模仿真是其中的关键所在。首先研究和探讨了平面相控阵天线仿真数学模型,给出了方向图数学函数。接着介绍了相控阵雷达系统建模中天线建模仿真的两种主要方法,多通道阵元级合成方法和方向图数据载入法。阵元合成法基于方向图数学函数给出了常规和差多通道的仿真算法,方向图载入法研究了如何对数据文件进行双线性插值来计算任意角度的增益。最后利用多通道阵元级合成方法进行了天线方向图建模仿真,通过仿真结果表明该算法的正确性,并说明两者仿真方法的适用条件。 相似文献
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A single-fed reconfigurable microstrip antenna that can provide various polarization diversities is presented in this paper. The antenna is excited by a microstrip feed line through aperture coupling. When two PIN diodes are used to respectively reconfigure the coupling slot and the open stub of the feed line, the polarization of the microstrip antenna can be switched between vertical and horizontal polarizations. For the reconfigurable antenna with the linear polarization diversity, it can be converted to a circularly-polarized antenna with switchable polarization sense by introducing a perturbation segment. Moreover, an antenna with the quadri-polarization diversity, including dual orthogonal linear polarizations and two circular polarizations, is also developed from the structure of the switchable circular polarization microstrip antenna, and only three diodes are required. Details of the antenna design are shown, and the measured results for the constructed prototype are also exhibited and discussed. 相似文献
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This paper proposes a reconfigurable beam‐steering antenna using a bended dipole and a loop. The radiation patterns of the two antennas are cancelled or compensated, and headed towards a specific direction when the dipole and loop antenna are combined at a reasonable ratio. The proposed antenna can steer the beam directions by controlling the operation of two artificial switches. The proposed antenna was manufactured on a PCB (FR‐4) and a flexible PCB (polyimide). In the case of the antenna that was fabricated on a PCB, the maximum beam directions were +50°, 0°, and –50° in the azimuth direction using the two artificial switches, and the antenna gain was 1.96 dBi to 2.48 dBi in the operation bandwidth of 2.47 GHz to 2.53 GHz. Also, the antenna was fabricated on a flexible PCB and measured under various bending conditions for wearable applications. 相似文献
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J.A. AnsariAuthor Vitae Anurag MishraAuthor Vitae P. SinghAuthor Vitae 《AEUE-International Journal of Electronics and Communications》2012,66(1):32-38
In the present paper W-slot loaded single and two dielectric layers microstrip patch antenna has been analysed using equivalent circuit concept. The antenna shows dual resonance. The resonance frequency of single layer patch is found to be 2.91 GHz and 3.88 GHz which increases for two layers dielectric antenna up to 4.17 GHz and 5.78 GHz respectively. The frequency ratio is found to be 1.33 for single layer patch antenna and 1.38 for two layers patch antenna. In general the frequency ratio is found to depend on slot length, slot width and slot angle. The bandwidth of single layer patch antenna is found to be 1.71% and 1.68% for lower and upper resonance frequency while it increases for two layers up to 5.28% and 2.77%. The theoretical results are compared with the simulated results obtained from IE3D and both are in close agreement. 相似文献