非对称单脊波导裂缝阵天线分析

将Elliott关于矩形波导裂缝阵理论推广运用到非对称单脊波导裂缝阵天线上,在考虑了裂缝外部互耦影响的情况下,给出相应的两个设计方程,同时给出8单元谐振裂缝线阵的具体计算和设计方法。加工样品的近场和远场测试结果证明了本文理论和设计方法是正确有效的。     

一种共面波导馈电的双陷波渐变槽天线

为了滤除WIMAX(3.3～3.8 GHz)和WLAN(5.125～5.825 GHz)窄带信号对超宽带系统的干扰,该文提出一款共面波导馈电的小型化双陷波渐变槽天线。共面波导结构可以有效地扩展天线的带宽,实现对整个UWB(3.1～10.6 GHz)频段的全覆盖。通过在天线的馈线上开L型缝隙和在辐射贴片上开一对E字型缝隙的方法,有效实现了在3.15～3.97 GHz和4.94～6.05 GHz频段的双陷波特性,能够抑制WIMAX和WLAN对超宽带系统的干扰。该天线结构简单紧凑,尺寸非常小,仅为40 mm×18 mm×0.813 mm。仿真和实测结果表明该天线在超宽带波段内具有良好的陷波特性、增益特性,可以应用于小型化超宽带系统中。文中方法对于陷波渐变槽天线的研究具有一定的借鉴意义。     

扁波导馈电的平板缝隙天线阵的带宽扩展

扁波导馈电的平板缝隙天线阵,除了馈电波导内部耦合增强以外,带宽也受到限制.文章从谱域角度分析了缝隙天线的内外场分布,在此基础上,得到了周期波导和金属波导中各模式场的功率/储能谱.计算了波导缝隙天线的Q值并分析其变化规律,解释了扁波导馈电带宽受限的原因是辐射波导内的驻波储能场增强造成的.提出了在缝隙两侧增加扼流槽的改进方案,并同样从谱域的角度分析了该方案对带宽改善的影响.将该方案应用于一个实际的SIW平板波导缝隙天线阵设计中,获得了8.1%的带宽.     

抑制共模噪声的SIW 平衡馈电差分缝隙天线阵*

提出一种利用差分天线在共模激励和差模激励下方向图不同来抑制共模噪声的方法,并基于该理论 设计了6×6 平衡馈电差分SIW 缝隙天线阵进行验证。该天线由6个宽边纵向SIW 缝隙天线子阵列组成。辐射缝隙 被设计为只在差模激励下辐射,达到抑制共模信号的目的。每个天线子阵采用平衡差分馈电方式,使用两个1分6 梳状功分器将6个子阵同时激励。整个天线使用标准PCB 工艺加工,为了测试共模和差模激励,分别设计了带有 180°相移的功分器和T型功分器用来生成差模和共模信号。在差模激励下,天线的最大增益为20.2dBi,S11幅值小 于-10dB 带宽为7.2%(39.6 ~43.8GHz),在共模激励下天线的最大增益为10.1dBi,在整个工作频段内S11幅值大于 -7dB。仿真和实验结果验证了该结构的SIW 缝隙天线对差模信号能够有效地辐射而对共模信号进行抑制。     

带有EBG反射板的缝隙多层宽带微带阵列天线

宽带微带天线多使用缝隙结构和多层结构,在扩展阻抗带宽的同时天线方向图副瓣与后瓣电平变大,降低了天线性能,限制了应用。小型化金属EBG结构反射板具有高阻抗表面特性,可利用其减小天线厚度提升方向图性能。通过结构设计与优化,相对于普通反射板结构,天线前后比提升了1.29dB,最大副瓣电平降低了3.16dB。天线至反射板的距离也被缩小至14mm（＜λ/4）,降低了天线剖面。测试结果说明,对于改善多层天线、缝隙耦合天线方向图特性,提升天线前后比,缩小天线厚度这种结构天线非常有效。     

Dual-Frequency Dual-Sense Circularly-Polarized Slot Antenna Fed by Microstrip Line

A new design of a dual-frequency dual circularly-polarized slot antenna is presented. The dual-frequency is achieved using a single-layer microstrip-fed configuration coupled to a modified annular-slot antenna. The dual sense circular-polarization is obtained by four unequal linear slots which augment the annular slot. Experimental results show the proposed antenna has good circular polarization characteristics for both right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP). The 10 dB return loss impedance bandwidths for the lower (RHCP) and higher (LHCP) bands are 26.7% and 11.3%, respectively. The 3 dB axial-ratio bandwidths are 6.1% and 6.0% with respect to 1.5 GHz (RHCP) and 2.6 GHz (LHCP), respectively.     

An Elliptical CPW Fed UWB Slot Antenna

A new CPW fed elliptical antenna for ultra-wideband (UWB) is proposed. The novelty of this antenna are very small size and uniplanar structure, which results in easy and low cost fabrication. This antenna has elliptical slot configuration which is fed by the CPW. This elliptical slot UWB antenna is enclosed in the extended surface of ground for decreasing the chip surface area. This antenna is designed with the optimal design parameters for the UWB spectrum. The designed antenna is printed on FR4 substrate and Vector Network Analyser is used for measuring return loss. The results of measurement results are similar to simulation results. The complete chip volume of antenna is 18.3?×?23?×?1.6 mm³.

     

共面波导馈电折叠缝隙对数周期天线的研究

超宽带天线是宽带电子系统中的关键部件。本文开展了折叠缝隙对数周期天线的电磁仿真和性能实验研究。根据对数周期偶极子天线的基本原理,设计了共面波导馈电的折叠缝隙对数周期天线。采用在折叠缝隙对数周期天线的折叠缝隙单元中加载相位槽的方法,进一步改善了天线低频端的驻波特性。对相位槽加载的折叠缝隙对数周期天线进行加工测试,测试结果表明在2 GHz~18 GHz的阻抗带宽内,驻波比小于3.5,与仿真结果吻合良好。设计了基于相位槽加载的共形LPFSA,给出了具体的仿真结果。本文的研究工作为该天线的实际应用提供了技术参考。     

非对称单脊波导裂缝阵天线分析

将Ｅｌｌｉｏｔｔ关于矩形波导缝阵理论推广运用到非对称单脊波导裂缝阵天线上，在考虑了裂缝外部互耦影响的情况下，给出相应的两个设计方程，同时给出８单元谐振裂缝线阵的具体计算和设计方法。加工样品的近场和远场测试结果证明了本文理论和设计方法是正确有效的。     

一种超宽带长槽阵列天线单元设计

针对地面对长槽阵列天线阻抗带宽的影响问题,设计出一种在激励偶极子上实施加载的超宽带长槽天线,其阻抗匹配带宽显著增加,最终得到了超过3. 5:1 的阻抗匹配带宽;在扫描范围内具有稳定辐射特性。该天线具有超带宽、剖面低、易共形等特点,在超宽带小型化相控阵天线中有良好应用前景。     

一种微带馈电的双阻带超宽带天线设计

设计了一种具有双阻带的超宽带天线。该天线由一个梯形的辐射单元和一个开有矩形槽的地板构成。并且通过在地板上开L 型和U 型缝隙,实现双阻带特性。该结果表明,天线工作带宽（VSWR<2）为8.6 GHz（2.9～11.5 GHz）,覆盖了UWB 频率范围,在3.2～3.9 GHz 和5～5.9 GHz 处形成了两个阻带,同时,这种天线在整个工作频率范围内有 良好的辐射方向特性。     

微带线-槽线馈电缝隙等角螺旋天线设计

被动雷达导引头为探测与跟踪目标可采用宽带等角螺旋天线,针对降低等角螺旋天线剖面,该文提出一种低剖面背腔式微带线-槽线馈电缝隙等角螺旋天线。微带线-槽线巴伦(Balun)中渐变微带线将同轴线激励的不平衡电场最终转化为槽线处平衡电场。实测结果表明,该缝隙等角螺旋天线实现了1:9的电压驻波比(VSWR)带宽,良好的辐射方向图与圆极化特性。在天线背面加入高度仅有0.05L(L为最低工作频率所对应自由空间中波长)的反射腔,腔内放置矩形环状吸波材料,有效拓展了天线低频段带宽。测试结果表明带有反射腔的缝隙等角螺旋天线实现了1:6.4的电压驻波比带宽,天线增益大于4 dB,良好的圆极化与方向图特性。平面化、一体化的馈电方式与低剖面反射腔有效降低了缝隙等角螺旋天线剖面,测试结果验证了该文所提出的微带线-槽线巴伦馈电缝隙等角螺旋天线设计方法的有效性。     

微带方形缝隙天线的阵列设计

根据理论分析的结果,设计了中心频率为35 GHz的微带方形缝隙直线天线阵列与圆环天线阵列。通过计算机仿真技术(Computer Simulation Technology,CST)微波工作室仿真可知,直线阵列的方向性系数达到17.32 dBi,当电压驻波比(Voltage Standing Wave Ratio,VSWR)小于2时带宽为4.371 GHz;圆环阵列的方向性达到10.1 dBi,带宽为5.07 GHz(VSWR<2)。因此其符合相控阵雷达的要求。     

具有双带阻特性的超宽带缝隙天线

设计了一款微带馈电的超宽带缝隙天线,整体尺寸仅有30 mm×30 mm×1.6 mm,在3.08～11 GHz范围内驻波比小于2,可覆盖超宽带频段.为了实现对WiMAX和WLAN频段的陷波,分别在地板和馈线上蚀刻不同缝隙,仿真结果表明:在3.2～3.7 GHz,5 ～5.9 GHz驻波比大于2,增益显著下降,而在通带内仍然保持良好的全向辐射特性和稳定的增益.该天线结构简单、性能优良,能广泛应用于超宽带通信系统中.     

一种新型矩形波导裂缝天线的分析与设计

针对任意两个横缝位于馈电矩形波导终端的短路圆盘上的情况.本文运用伽略金方法分析了一种新型双裂缝天线的反射与辐射特性:分析中考虑了缝隙间的内部互耦与外部互耦:根据分析结果,首次设计并研制了这种工作于C波段的新型天线,实验结果和设计指标吻合较好.它适合高速飞行器载体的特殊应用.     

射频识别系统微带二元天线阵的设计

本文介绍了目前常用的一些射频识别系统天线,并简要分析矩形微带天线的工作原理,在此基础上,设计出一种工作在2.45GHz的微带二元天线阵,同时在同相侧馈的馈电网络中进行天线的阻抗匹配。最后测得天线的驻波比、输入阻抗、增益和方向图。结果表明,二元阵天线的增益明显优于普通贴片天线,适合作为射频识别系统天线使用。     

Study and Design of a Differentially-Fed Tapered Slot Antenna Array

The results of a parametric study and design of an ultrawideband dual-polarized array of differentially-fed tapered slot antenna elements are presented. We examine arrays of bunny-ear antennas and discuss the capabilities and limitations of differential antenna technology. As we focus on radio astronomical applications, the absence of a balancing-feed circuit not only reduces the first-stage noise contribution associated to losses in the feed, but also leads to a cost reduction. Common-modes are supported by the antenna structure when a third conductor is present, such as a ground plane. We demonstrate that anomalies may occur in the differential-mode scan impedance. Knowledge of both types of scan impedances, differential and common mode, is required to properly design differential LNAs and to achieve optimal receiver sensitivity. A compromise solution is proposed based on the partial suppression of the undesired common-mode currents through a (low loss) balancing-dissipation technique. A fully steerable design up to 45$^{circ}$ in both principal planes is achieved.      

Compact Switched-Beam Antenna Employing a Four-Element Slot Antenna Array for Digital Home Applications

In this paper a compact switched-beam antenna is proposed. The antenna is composed of a four-element antenna array based on L-shaped quarter-wavelength slot antenna elements. Such an antenna element is a planar structure and presents a directional radiation pattern in the azimuth plane. Its maximum radiation direction is toward near the direction of the open end of the slot. As a result, the open ends of the four slot antennas are arranged toward $0, pi/2, pi$, and $3pi/2$ , respectively. The statuses of these antennas are controlled by some diodes. Consequently, by carefully controlling the diodes, an antenna with several switchable patterns can be achieved. To prove the concept, a 2.4–2.5 GHz switched-beam antenna for WLAN applications is designed and implemented. Its size is 52 mm in square. The antenna possesses eight directional patterns and many nearly omnidirectional patterns in the azimuth plane. The experiment results fully demonstrate the performance of the proposed design. The envelope correlations and the characteristics of the designed antenna are also discussed. Due to the compact size and low manufacture cost, such a design can be a promising solution for digital home applications to overcome multipath problems and increase the transmission data rate.      

双频共面单脉冲天线研制

论述了双频共面单脉冲天线的设计方法。天线口径较小时,馈源的遮挡口径相对较大,这对天线的性能影响很大,选择口径较小的双频馈源是实现双频共面的关键。天线低频段馈源采用4喇叭单脉冲形式,高频段馈源采用单口多模单脉冲喇叭,通过各自的馈电网络实现单脉冲功能。天线采用卡塞格伦形式,通过对天线和馈源的优化设计,可实现天线双频段工作性能,实测结果与计算结果基本吻合。     

双弯曲赋形反射面天线的外形选择

对双弯曲赋形反射面外形特征进行了理论分析，研究了不同外形反射面对天线电性能的影响，给出了选择反射面外形的方法，对双弯曲赋形反射面天线的设计有一定的帮助。