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设计制作了一种用于无线通信移动终端的方向图可重构阵列天线.该阵列天线由一个激励单极子和四个长度可调的寄生印刷单极子组成,可工作于两种模式,阵列波束在方位面内有八种不同的指向.通过控制PIN开关的状态,寄生单元可以在引向器和反射器之间切换状态,方向图的主瓣指向开关断开的阵元方向.阵列天线方向图可以以45°步长覆盖方位面,工作频带覆盖WiMAX (3.40-3.69GHz)频段,辐射增益大于6dBi.在两种模式中各选取了一个指向状态,对其回波损耗和方向图进行了实测,实测结果与仿真结果吻合较好. 相似文献
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阵列天线综合一般是基于理想的单元天线方向图,而不考虑阵元间的互耦。本文提出了一种考虑互耦的基于遗传算法的阵列天线综合方法。该方法首先利用商用仿真软件分别计算阵列中各个阵元在阵列中的方向图,再通过遗传算法优化出目标方向图。通过实例比较可以看出,这种方法能够比较精确的仿真计算阵列的方向图,易于在工程上实现高性能的天线阵列系统。 相似文献
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本文提出一种新型综合阵列天线方向图的模式方法。该方法基于双正交模式理论,考虑了阵元之间的耦合作用的影响,可以对任意形状的阵列天线进行方向图综合。利用双正交模式综合方法可以快速有效地获得每个阵元的特定激励,以期阵列天线的方向图满足特定的需求。模式组之间的双正交特性保证了该方法所得天线阵列方向图与期望方向图之间良好的一致性。通过对所需电场的加权,可以将整个球面上的二维曲面积分运算转化为一维线积分运算,使得方向图综合过程的计算量大为减少。若干阵列天线方向图综合实例验证了该方法的正确性和有效性。 相似文献
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传统的球形共形天线阵列馈电网络复杂,每个天线单元需要单独馈电和控制相位,导致天线阵列效
率较低。文中提出了一种采用口径耦合馈电的单馈球面共形全向天线阵。为球形天线阵列设计了一个1 分30 的馈
电网络且直接集成在了阵列内部。这样可以通过一个端口给所有的天线单元馈电,从而降低了馈电的复杂度,提高
了天线效率。阵列的方向图在x-y 平面上是全向的。x-y 平面的增益变化小于1 dB,x-z 平面的半功率波瓣宽度约为
120°,实现了比传统全向更大的空间覆盖范围。天线的方向图最大增益为1 dBi。 相似文献
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张勇 《电子信息对抗技术》2017,32(1)
提出了一种小型超宽带(UWB)平面天线阵列并进行了优化.首先设计了两个不同的UWB天线单元方案:印刷天线-Vivaldi天线、平板天线-平面螺旋天线,并通过对比选择螺旋天线单元作为组阵单元.对该天线阵列的回波损耗、3D辐射图、方向图进行了仿真计算和设计.结果该天线阵列在6 ~ 10GHz内具有较好的定向辐射特性,增益达到15dB.进一步优化单元空间分布结构,使天线在相应频段内具有更佳的方向性.通过调整各个馈源的相位差,在不失去增益的同时,可以控制波束的偏转. 相似文献
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系统地描述了MIMO分集性能衡量指标,并对空间分集、方向图分集、极化分集进行了概念描述。进而根据MIMO系统天线设计的要求和特点,结合新型MIMO系统天线单元和天线阵列,分析了其设计思路,同时重点设计了一种用于MIMO系统的终端阵列天线,即单层矩形切角贴片天线,并对其S 参数和方向图进行了模拟和分析。模拟结果对合理设计MIMO系统发射和接收端天线阵列具有现实意义。 相似文献
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八木天线是一种常用的天线形式.本文将Minkowski分形环应用于八木天线设计中,利用分形结构的空间填充特性来减小天线的横向尺寸,从而实现天线小型化设计.设计了工作于880~960MHz的6元二阶Minkowski分形环八木天线,以矩量法为核心对设计天线进行数值分析,将线天线模拟为细带线模型,天线表面采用三角单元进行剖分,RwG基函数作为电流展开函数.同方环八木天线进行了比较,在驻波特性、辐射特性相似情况下,分形环八木天线的尺寸缩减了29.8%. 相似文献
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The Pade rational function fitting model commonly used for model-based parameter estimation (MBPE) in the frequency domain is enhanced to include spatial dependence in the numerator and denominator coefficients. This allows the function to interpolate an antenna radiated electric field pattern in both the frequency and spatial domains simultaneously, such that a single set of coefficients can be used to accurately reconstruct an entire radiation pattern at any frequency in the fitting-model range. A simple procedure is introduced for transforming interpolated electric fields into gain patterns using input impedance versus frequency curves also obtained via MBPE. The utility of this method is demonstrated by applying it to a dipole antenna over a frequency range of 150-950 MHz and using a polynomial representation in &thetas; for the coefficient spatial dependence. It is also used to estimate radiation patterns for a three-element Yagi array between the frequencies of 470 and 500 MHz using a binomial representation for the spatial variation that includes terms dependent on &thetas; as well as φ. The use of this method for interpolating radiation patterns has at least two significant advantages; one being large compression ratios for the amount of data that must be stored to accurately reproduce patterns and the other being a significant decrease in the amount of time required for modeling problems with large computational domains 相似文献
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A New High-Gain Microstrip Yagi Array Antenna With a High Front-to-Back (F/B) Ratio for WLAN and Millimeter-Wave Applications 总被引:1,自引:0,他引:1
Gerald R. DeJean Manos M. Tentzeris 《Antennas and Propagation, IEEE Transactions on》2007,55(2):298-304
A new printed microstrip Yagi array antenna is proposed that can achieve a high gain and low backside radiation for various applications up to the millimeter-wave frequency range. The high front-to-back (F/B) ratio (up to 15 dB) is attributed to the constructive interference that takes place between the individual printed Yagi arrays in the design. Through the spacing of the elements, the directivity (between 9-11.5 dBi) and the F/B ratio can be altered to suit the application of interest. The operational principles of this design are discussed to give insight on the radiation mechanism of the antenna. An initial design at around 32.5 GHz is presented to show the performance capabilities of this configuration. An impedance bandwidth of 8.3% can be achieved around this frequency. Then, a parametric analysis is conducted to estimate the significance of the design parameters that affect the antenna's performance. Finally, measured return loss and radiation pattern performance at 5.2 GHz is displayed to validate the principles and simulated results of the design. The measured impedance bandwidth of 10% is achieved. The F/B ratio is 15 dB which is larger than values previously published by 5-10 dB. Additionally, a gain of 10.7 dBi is observed. To the author's knowledge, this is the first microstrip Yagi array antenna presented that has a high gain and a high F/B ratio designed using simple fabrication techniques 相似文献
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对八木微带天线进行了研究。仿真设计一种宽带宽波束圆极化八木微带天线,在中心频率上实现了波束由侧射向端射偏转26°,频率带宽达800MHz,0dB主波束宽度为110°;采用Wilkinson微带功分器产生两路幅度相等相位相差90°信号对天线进行馈电,实现了圆极化。同时研究了在设计天线中参数对于八木微带天线主波束偏转角度的影响,得出了偏转角度随各参数变化的一般规律。 相似文献
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Simplified feed for modified printed Yagi antenna 总被引:1,自引:0,他引:1
A modified printed Yagi antenna with a simplified feed mechanism is proposed. In the new design, the driver dipole is fed by a transmission line formed by two parallel strips printed on opposite sides of the dielectric substrate. This simplified feed structure results in the reduction of the transmission line length, and, consequently, the radiation losses. The analysis of the modified Yagi antenna is performed numerically using Ansoft high frequency structure simulator and is experimentally validated. 相似文献
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提出了一种宽带印刷套筒天线,此天线通过选择三角渐变的辐射贴片和平面的套筒结构实现了宽频带特性,在VSWR<2.5 时实测阻抗带宽可覆盖450~1150 MHz,可用于覆盖数字电视频段(470~862 MHz)。同时辐射方向图在水平面也具有良好的全向性。通过顶加载的形式有效地降低了天线的实际高度。 相似文献
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A switchable Yagi-Uda antenna prototype with radiation pattern reconfiguration is presented in this letter. The proposed reconfigurable antenna is based on the concept of switching between the reflector and director of a Yagi-Uda antenna using a radio frequency PIN diode. As a result, the minimum/maximum radiation can be steered towards desired signals or away from interfering signals in opposite directions. The measured 10 dB impedance bandwidth and gain are 210 MHz (7%) and 8.02 dBi at 3 GHz, respectively. Details of the antenna design and its performance are described and empirically analyzed. 相似文献
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提出了一种基于新型人工表面等离子体激元(Spoof Surface Plasmon Polaritons, SSPPs)馈电带有引向器的低剖面宽带八木天线阵列。天线阵列包括两部分:基于人工表面等离子体激元波导的四路宽带功分器和八木天线阵列。人工表面等离子体激元具有高的场局限性,将信号束缚在人工表面等离子体激元的凹槽结构中保证了信号的高效传输,减少了传输损耗。八木天线通过进一步加载引向器结构能够实现端射辐射特性。测试结果表明:天线阵列的回波损耗在4.5 ~6.05 GHz 频率范围内小于-10 dB。天线阵列实际增益在4.5 ~ 6.05 GHz 范围内最高可达11.1 dBi。 相似文献
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《Electronics letters》2008,44(25):1448-1450
A novel asymmetric fork-like monopole antenna for digital video broadcasting-terrestrial (DVB-T) signal reception for application in the UHF band is presented. The proposed antenna consists of two two-branch strip monopoles on a rectangular ground plane with a concave. The concavity in the ground pattern serves as an effective means for the gap between the radiating element and the ground plane for impedance matching. The influence of various parameters on antenna characteristics has been investigated. Results show a wide bandwidth of 461 MHz (451?912 MHz) or 70% of DVB-T centred frequency (655 MHz). The proposed antenna has omnidirectional radiation patterns in the yz-plane. Details of the proposed antenna design and experimental results of the constructed prototypes are presented. 相似文献