基于新型缝隙单元的微带全向阵列天线设计

提出了一种新型串行馈电的全向缝隙阵列天线，在带状线两侧背靠背刻蚀8对圆环缝隙，在缝隙内部加载一个Y形缝隙，延长Y形缝隙的长，并在顶部刻蚀横槽，形成最终的Y-T型缝隙结构，用以提升单元辐射性能。采用遗传算法(GA)对阵列进一步优化，使其工作带宽进一步扩宽，增益有所提升。根据设计结果加工制作了天线样品，实际测试表明，天线的|S11|<-10 dB阻抗带宽为7.93% (5.56~6.02 GHz)，带宽内峰值增益均高于8.99 dBi。工作在5.8 GHz处，E面旁瓣水平低于-10.11 dB，峰值增益为9.43 dBi, 且有稳定的全向辐射性能。     

一种用于超高频电磁信号检测的单臂阿基米德螺旋天线的设计

研究了一种50Ω同轴电缆直接馈电的单臂阿基米德螺旋天线,通过优化仿真设计了天线各项硬件参数,实现了其在UHF(超高频)段的工作。通过锥形金属片过渡馈电的方式保证了天线结构的稳定性,克服了单臂阿基米德螺旋天线偏心馈电带来的不良影响。通过改进天线的终端结构,节约了天线制作材料,提升了天线的整体性能。通过仿真分析研究了天线介质材料、馈电圆锥角、天线占空比等对天线性能的影响,并进行了优化设计。结果表明,设计的天线结构简单无需馈电巴伦,其工作频带为:1.15GHz~2.4GHz,具有良好的圆极化特性,在工作频带范围内天线最大辐射方向具有5dB以上的增益,基本满足超高频电磁信号的检测要求。     

加载电磁带隙EBG反射板的低电磁辐射比吸收率SAR天线

如何减小移动通信中移动终端电磁信号对人体脑部的影响成为公众关注的焦点之一,电磁带隙(EBG)结构在其禁带内具有阻抗高、反射波与入射波位相相同的特点,可以抑制印刷线路板的表面波改善天线辐射性能,减少进入脑部的电磁信号。在1.8 GHz频段,对加载EBG结构的反射板的天线系统进行了仿真,结果表明,与未加载EBG的天线系统相比,加载EBG结构的偶极天线系统不仅可以保证天线的辐射增益,同时人体脑部电磁波的比吸收率大大降低,加载EBG反射板可以有效抑制人体脑部的电磁场强度;由于天线与反射板的互相耦合,天线的尺度与未加载EBG结构的天线相比尺度变小,同位相反射偶极天线与EBG距离很近,实现了低轮廓天线。     

一种超宽带,低交叉极化,低剖面的相控阵天线单元设计

针对传统Vivaldi天线非主平面扫描时交叉极化恶化的问题,设计了一种可用于工程实际生产的超宽带天线单元对其进行优化。该天线单元利用沿辐射方向分布的尺寸渐变的金属片替代了传统Vivaldi天线指数渐变的槽线结构,工作频带约为7~16GHz,并显著改善了交叉极化。仿真结果表明,该天线在2.3倍带宽内匹配和辐射性能良好,与传统Vivaldi天线相比在D平面交叉极化优化约25dB,并具有剖面低,结构简单,易于实现等优点,可以作为宽带相控阵单元。     

宽频带的微带等角螺旋天线设计

为了实现宽频带天线指定方向的高性能辐射，设计了一种宽频带的微带等角螺旋天线。为实现阻抗匹配，天线馈电部分设计了一种指数渐变式微带巴伦结构。经过实物测试参数，结果表明加入了指数渐变巴伦结构后天线实现了良好的阻抗匹配并具有良好的宽频带特性，其工作带宽为1.74～4.82 GHz，回波损耗最低达- 30 dB。同时设计了一个平底型金属反射腔用于反射背向电磁波，在保持宽频带工作特性的同时，使天线具有了良好的单向辐射特性，天线在整个工作频段内的增益均大于6 dB，与传统的螺旋天线相比，具有宽频、定向、高增益的特点，具有一定应用前景。     

PBG结构圆柱形微带贴片天线的设计与仿真

本文利用光子晶体带隙(PBG)结构的特点,将特殊设计的 PBG 结构应用于圆柱形微带贴片天线中。在同轴线馈电的圆柱形微带贴片天线的介质上蚀刻出按一定规律排列的 PBG 结构,并基于 HFSS 对特殊设计的 PGB 结构圆柱形微带贴片天线和普通的圆柱形微带贴片天线进行仿真和优化,仿真结果表明,按照一定规律排列的 PBG 结构可以有效抑制天线表面波的传播,明显提高圆柱形微带贴片天线的带宽和增益,有效改善圆柱形微带贴片天线的辐射方向图,实现天线性能的优化设计。     

一种基于方向图重构机制的宽带宽视角相控阵天线

本文提出了一款风车形方向图可重构单元及其作为阵元的二维平面宽带宽视角扫描相控阵天线。所提出的单馈方向图可重构单元天线由辐射贴片、直流偏置电路以及宽带人工磁导体(Artificial Magnetic Conductor, AMC)反射面构成。其中,辐射贴片为馈电结构可重构的四个Vivaldi缝隙组成的风车形贴片,它能够通过改变PIN二极管的通断以实现宽带内四个端射方向上的波束切换。此外,将AMC反射面加载于辐射结构的后端,使得最大辐射方向由原来的端射方向调整为准端射方向,这样有利于单元天线组阵后的扫描波束能够覆盖到侧射方向。对该天线单元及其构建的8×8均匀平面相控阵天线进行了仿真与分析。仿真结果显示,所设计的阵列天线同时具备了宽带宽视角二维波束扫描性能,其在5.4 ~ 6.1 GHz的工作频带内可以实现±60°范围内的二维波束扫描。同时,阵列的增益波动小于4.3 dB,并且具有较低的旁瓣电平。     

24 GHz平面宽波束阵列天线设计

为满足车载毫米波雷达系统在盲区探测、防撞预警等应用场景时宽视场角的需求,设计了一款平面宽波束微带阵列天线。采用平面微带天线作为基本辐射单元组成3元阵列,提高天线增益。阵列天线采用背馈式同轴馈电,通过特定的馈电网络,使天线三个阵元的馈电功率之比为05∶1∶05,提高天线增益的同时抑制副瓣电平。并在平面天线的基础上添加寄生单元和开槽结构,进一步拓宽了天线的波束宽度,改善了天线的阻抗匹配性能。天线使用三维电磁仿真软件HFSS仿真验证,仿真结果表明该天线可工作于224～258 GHz,E面和H面3 dB波束宽度分别为49°和81°,天线最大增益为94 dB,第1副瓣电平小于-20 dB。天线整体尺寸为175 mm×119 mm×1308 mm,便于平面化应用和设备的小型化,有一定参考应用价值。     

使用石墨烯的超宽带轨道角动量螺旋天线设计

轨道角动量涡旋波束各个模态之间相互正交,可以很好地解决频谱资源紧张的问题。针对目前轨道角动量天线普遍存在带宽较窄的问题,设计了一种太赫兹频段的超宽带轨道角动量四臂螺旋天线。研究了馈电端口之间连续相位差与生成模态之间的关系,使用了一种石墨烯双环结构并通过调整优化天线的的结构尺寸来提高天线的性能。实验结果表明,通过简单调整馈电相位差,就能够产生模态数为0、1、2和3的涡旋波,并且不同模态下天线的增益均在7.5 dBi以上。同时所设计的天线绝对带宽达到了8.85 THz,在中心频率6 THz处其相对带宽可以达到147%,S₁₁为-50 dB,与传统天线相比改善较大,为太赫兹频段的模态复用提供了一定的现实意义。     

一种适用于GSM/WLAN/WiMAX应用的U型槽三频天线

本文提出一种嵌套U型槽结构矩形微带馈电多频平面天线,可用于全球移动通信系统、全球微波接入和无线局域网。三个工作频段由一对互相嵌套的U型槽和矩形结构实现。所设计的天线尺寸为40×30mm²。结果表明,该天线的10dB阻抗带宽分别为130MHz、240MHz和170MHz。该天线在三个工作频段上均表现出良好的辐射方向图和可接受的增益。     

Gain enhancement and broadband RCS reduction of a circularly polarized aperture-coupled annular-slot antenna using metasurface

A circularly polarized microstrip slot antenna with low radar cross-section (RCS) and high gain was designed using a metasurface composed of a \(6 \times 6\) array of corner-truncated square patches placed on top of the upper substrate. By optimizing the geometry of the metasurface patches and L-shaped feed of the proposed antenna, broadband RCS reduction and improved overall antenna performance were achieved. A prototype antenna was fabricated, and the results showed that the proposed antenna exhibited an impedance bandwidth of 29.08 % in the frequency band of 4.29–5.75 GHz. The designed antenna achieved good 3-dB axial ratio (AR) bandwidth of about 30.18 % with center frequency of 5.3 GHz, and gain in the broadside direction of 9.9 dBi. Using the designed metasurface, remarkable monostatic RCS reduction was obtained in the frequency range from 4 to 13 GHz.     

紧凑型超宽带 MIMO 天线的研究

针对当前超宽带多输入多输出(UWB-MIMO)天线存在尺寸大、隔离度低等缺陷,设计了一款紧凑型UWB-MIMO天线,天线尺寸仅有41 mm×25 mm×1.6 mm。通过扳手形微带馈线扩宽天线的带宽,在天线的接地平面上引入锯齿形和梳状电磁带隙结构以获得较高的隔离度;加载C形枝节形成陷波以抑制X波段的下行频段对超宽带系统的干扰。实验结果表明,所设计的UWB-MIMO天线的阻抗带宽为3.1～12.0 GHz,陷波频带为7.0～7.9 GHz;在整个工作带宽内,隔离度大于20 dB。设计的UWB-MIMO天线具有良好的辐射特性、稳定的增益和较低的包络相关系数(ECC<0.006),适用于UWB-MIMO系统应用。     

Design,modeling and analysis of dual-feed defected ground microstrip patch antenna with wide axial ratio bandwidth

In this paper, a low profile microstrip patch antenna with defected ground structure is proposed for wide impedance and axial ratio bandwidth. The antenna structure consists of two feed lines with a circular defect loaded in the ground surface. The proposed antenna shows an impedance bandwidth of 71.92% ranging from 8.95 to 19 GHz covering X, Ku and K band applications. The mutual coupling between the two feed lines is suppressed by means of a single and double arc-shaped defect embedded in the ground plane. The mutual coupling is suppressed to a level of ? 37.5 dB with improved radiation performance. The measured 3-dB axial ratio bandwidth of the proposed antenna ranges from 8.85 to 11 GHz. An equivalent circuit model of the designed antenna is also proposed for theoretical analysis and theoretical results are verified with simulated and measured results.     

垂尾隐蔽式超短波全向天线的一体化设计

以单极子天线为研究对象,首先对传统单极子天线的工作原理进行了分析,并研究了不同情况对天线性能的影响,然后在此基础上提出了一种新型结构的平面单极子天线,它选用三角形的结构,并采取了加载元件、提升馈电点等技术,有效地减小了平面单极子天线的结构和尺寸,与此同时,有效地实现了天线带宽的展宽,并且在设计中采用了加载技术,实现天线性能的进一步优化.在理论分析的基础上,使用电磁场仿真软件HFSS对天线进行了仿真分析,通过参数扫描得到了天线的最佳尺寸,并分析了天线的方向图和增益等特性.然后对3种不同情况下的天线进行仿真与分析,分别是无限大地平面、有限大地平面、加入钉子和灯泡的复杂结构后,并优化其参数使其获得最佳的特性.最后根据以上仿真结果,提出了复杂结构垂尾隐蔽式超短波天线的一体化设计的方法.并进行了综合仿真,实现了在100～400 M的频段内驻波比小于2.75.     

任意形状带隙结构电磁散射特性的精确分析

基于RWG基矩量法（MOM）的基本原理,提出了任意形状目标带任意形状缝隙后电磁散射的一体化分析方法。首先,从表面积分方程（SIE）出发,利用等效原理结合矩量法对目标进行了严格的理论建模,推导出适合编程求解的矩阵方程。然后,通过数值仿真并与相关测量结果对比,验证了该算法的有效性。最后分析了直缝隙宽度、深度对模型整体雷达散射截面（RCS）性能的影响,并讨论了折线型缝隙相对于直缝隙的RCS减缩性能。     

基于有限元法的背腔微带贴片天线的散射研究

雷达散射截面(RCS)是目标天线的一个重要指标参数,雷达截面缩减就是控制和降低军用目标的雷达特征,迫使敌方电子探测系统和武器平台降低战斗效力,从而提高军用目标的突防能力和生存能力.因此,减小RCS一直是天线发展的重要方向.文中根据变分公式,计算新型背腔微带贴片天线的散射场.使用混合有限元边界积分法,将问题转化为一个矩阵方程的求解.通过分析不同的天线结构和不同的填充介质对天线RCS的影响,给出数值结果,从而看出这种方法的精确性和有效性.     

A miniaturized slotted multiband antenna for wireless applications

A novel miniaturized slotted multiband antenna is presented in this article. The antenna consists of a kite-shaped slot in the radiating patch to obtain miniaturization, C- and G-shaped slots in the ground plane to incorporate multiband operation and a microstrip feedline to obtain an impedance matching. The aforementioned miniaturization method results in about 50% reduction in active patch area and about 36% reduction in volume of the proposed design, as compared to the conventional antenna. G-shaped slot is used to obtain operations at 3.6 and 5.8 GHz, while C-Shaped slot is used to obtain operations at 6.9 and 9.5 GHz. The antenna has an active patch area of only 384 \(\hbox {mm}^{2} (24\times 16\,\hbox {mm}^{2})\), and the entire performance analysis of the antenna are carried out using HFSS v.13.0 simulation software. The proposed design operates at about 3.58 (WiMAX), 5.9 (WLAN), 6.72 (Satellite TV), 8.51 and 9.76 GHz (X-band) with \({S}_{11}<-\,10\,\hbox {dB}\) bandwidth of about 1.95% (3.54–3.61 GHz), 3.5% (5.88–6.09 GHz), 1.7% (6.68–6.80 GHz), 4.4% (8.36–8.74 GHz) and 3.96% (9.4–9.78 GHz), respectively. The proposed structure is compact in size, simple in construction, low profile, easy to fabricate, exhibits good impedance matching, moderate gain and stable radiation characteristics across the operational bandwidths.     

A new approach to analyze a resistive patch antenna excited by a microstrip line and printed on an anisotropic substrate with superstrate

An improved model is presented to study the effect of a superstrate on a resistive rectangular microstrip antenna fed by a microstrip line and printed on anisotropic substrate. A new accurate computation with different unknown currents of the electric field on overlap, feed line and resistive patch is studied by the Fourier transform, considering the Galerkin’s method and entire domain basis functions. Additionally, the scattering radar cross section (RCS) was studied for this novel resistive patch taking into account the effect of the nonzero surface resistance, the superstrate and the anisotropic substrate. To determine the unknown current modes on the patch, the electric field integral equation can be discretized into a matrix form that incorporates the effect of the superstrate, the anisotropic substrate and the currents on the feed line which are efficiently developed. Moreover, the necessary terms to represent the resistive patch are derived and are included in the equation in the form of a resistance matrix. RCS reduction is obtained for high superstrate thicknesses and low superstrate permittivities. Also, the addition of a resistance on the surface of the patch antenna provides a scattered energy diminution. Moreover, the RCS of this novel structure is affected by both \(\varepsilon _z \) and \(\varepsilon _x \) permittivities change, however, has drastically changed due to the \(\varepsilon _x \) permittivity change. In order to validate the theoretical results, a study has been achieved for a perfectly conducting patch on isotropic substrate, without superstrate and excitation, and the results were compared well with other papers. This subject has not been treated or reported previously in the literature, and there has been very little work on the scattering RCS of only simple perfectly conducting patch antennas.