宽带高增益圆极化微带-喇叭组合天线

研究了一种具有良好工作性能的微带-喇叭组合右旋圆极化天线,首先设计了一种双层宽带圆极化微带天线结构,同时满足电压驻波比(VSWR)≤2,轴比(AR)≤4 dB的频带宽度(Bw)≥24%,主极化增益大于9 dBi;通过引入角锥喇叭结构,在工作频带内将天线增益提高到12 dBi以上,同时不影响原天线的其他性能。为更好了解微带-喇叭组合右旋圆极化天线的性能,并快速而准确地设计该天线结构,对天线主要几何参数进行了适当分析和研究。     

一种透射型线-圆极化转换超表面的设计及应用

提出了一种单对角线开缝的方形单元构成的透射型极化旋转超表面,并将其应用于宽带圆极化微带缝隙天线的设计中。采用等效电路法分析了超表面实现线-圆极化转换的工作机制,并对天线圆极化带宽的影响因素进行了参数扫描。仿真结果表明:加载超表面使线极化微带缝隙天线产生了圆极化辐射;同时,扩展了天线的阻抗带宽。天线相对阻抗带宽达到了33.2%,3 dB轴比带宽达到了19.5%,在阻抗带宽内天线增益均高于6.8 dBi,证实了新型超表面结构具有良好的极化旋转特性。     

一种改进的圆极化三角形口径耦合贴片天线

提出并设计了一种改进的宽带圆极化三角形口径耦合微带贴片天线。该天线由L形微带线、三角形缝隙和三角形贴片组成。通过L形微带线形成圆极化,三角形缝隙和三角形贴片形成单向辐射,缝隙和贴片印刷在不同的介质基片上以提高天线增益并缩减口径尺寸,同时在三角形贴片上切去一个角改善天线的圆极化特性。用HFSS设计了一款L波段的口径耦合贴片天线。仿真结果表明,天线的阻抗带宽26.5%,圆极化带宽22.5%,平均增益7.7 d B。     

基于环形极子的太赫兹超宽带圆极化阵列天线

以方环单极子天线为基础,设计了一种太赫兹频段超宽带圆极化微带阵列天线。提出的新型低剖面环形天线单元由C型结构和改进后的接地结构组成,实现了天线表面电流不对称流动以及电流的最优纵横比,辐射圆极化波;采用2×4天线阵列不仅提高了天线增益,而且增强了其方向特性。仿真结果表明,该阵列天线的阻抗带宽为67.42%(193.86～391.02 GHz),圆极化轴比带宽可完全包含该频段,且在该频段内峰值增益为15 dBi,在太赫兹通信设备中具有广阔的应用前景。     

加载EBG反射板的圆极化偶极子天线

本文介绍了一种通过加载电磁带隙结构(Electromagnetic band gap,EBG)反射板来辐射圆极化电磁波的偶极子天线。该EBG反射板由矩形单元组成7×5阵列,印制偶极子天线谐振中心频点是5.2GHz。从仿真结果看,该偶极子天线能够有效地辐射圆极化波,阻抗带宽达到了0.65GHz,极化带宽达到了0.13GHz,天线增益达到了7.8 d B。     

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。     

带异形反射腔和寄生螺旋的均匀升角轴向模螺旋天线

为了改善轴向模螺旋天线的辐射特性,在带有寄生螺旋的均匀升角轴向模螺旋天线基础上,设计了一种带有曲反射面背腔的螺旋天线,并用HFSS软件对天线的辐射特性进行了仿真分析。通过对比几种不同形式的螺旋天线的仿真结果,证明了该种螺旋天线可以有效地提高轴向模螺旋天线增益系数,圆极化一致性良好,是一种提高轴向模螺旋天线性能的有效方法。     

用增益比较法测量大型反射面天线增益

介绍了用增益比较法测量大型反射面天线增益的方法，给出了存在地面反射时的修正公式，并对圆极化天线的增益测试进行了分析，对于实际工程应用有参考价值。     

宽带平面螺旋天线的研究与设计

平面螺旋宽带天线具有频带较宽、体积较小、圆极化性能较好等特点,应用范围很广。但是这种天线增益较低,馈电匹配较难实现,尤其是前者,使得其性能大打折扣。通过研究影响平面螺旋宽带天线增益和馈电匹配的主要因素,设计了2~7GHz范围内的宽频带平面螺旋天线。理论分析和仿真实验结果表明,对改善平面螺旋宽带天线的性能有一定的工程参考价值。     

利用线极化天线快速测量圆极化天线轴比的方法

针对轴比测试需要连续旋转线极化天线极化轴,在高频段旋转关节难以消除高速旋转带来的电缆抖动所引起的幅度和相位不一致性,提出了一种快速、精确测量圆极化天线轴比的测试方法。基于椭圆极化波的正交分解理论,该方法利用线极化天线对待测圆极化天线进行两组正交的线极化幅度测量,通过计算得到圆极化天线的轴比等极化椭圆参数的信息。在此基础上又提出了只用三个线极化分量测量圆极化天线轴比的方法。通过在微波暗室中对圆极化天线进行多次测试,验证了该方法的有效性。该方法提高了圆极化天线的测试效率,降低了测试难度,对于工程应用有重要的应用价值。     

Miniaturization of an Ultra‐Wideband Antenna with Two Spiral Elements

In this letter, novel antennas with two spiral elements are presented for ultra‐wideband application. The original antenna consists of a T‐shaped microstrip feed line, two spiral radiating elements, and a ground plane with two circular slots. It measures 30 mm × 40 mm × 1.6 mm. Spiral elements are used to increase the lower bandwidth limit. To further reduce the size of the antenna, the original antenna is cut in half by using the symmetry of the surface current distributions. The proposed antennas feature omnidirectional radiation patterns and good gain flatness.     

集装箱表面的超高频RFID标签天线设计

提出了一款用于集装箱上的超高频RFID标签天线。从实际制作角度详细分析了天线与金属板的不同距离和金属板不同尺寸对天线参数的影响。结果表明,通过适当选取天线与金属板的距离以及联系实际的使用环境,其阅读距离基本满足要求,并且金属板尺寸的增大,使天线的增益也随着增大,但对天线的匹配影响较小,适合集装箱上RFID标签天线的应用。     

面向车载鲨鱼鳍的宽频MIMO天线设计

为了解决车载通信天线工作频带窄、尺寸大等缺点,文中提出了一款应用于车载鲨鱼鳍外壳的新型小型化、宽带MIMO天线。为了实现天线的宽带特性,充分利用了印制单极子天线易于引入多谐振的特点,首先通过合理的尺寸设计,将单极子天线谐振频率设计至工作频段中;然后,使用缝隙加载技术,增加天线谐振模式数量并改善天线阻抗匹配特性,拓宽了天线带宽并实现了天线的小型化。为了验证天线实际性能,将天线安装于鲨鱼鳍外壳中进行了测试。结果表明,该天线可以覆盖824～5 000 MHz的频段范围,驻波比均小于3,增益最低1.9 d Bi、最高6.2 d B,效率均高于49.5%、最高达89.2%。该天线可满足车载通信系统对天线的宽带化和小型化要求。     

UHF频段RFID读写器天线小型化设计

RFID天线通过贴片切角、挖方形槽以及接地板开十字形缝隙的方法来减小尺寸、实现圆极化和提高天线增益,通过对参数的优化仿真最终使天线轴比接近1d B,增益达到-0.69d B,尺寸比传统天线减小了21%,满足我国UHF频段的要求。     

2．55～17GHz小型化圆锥天线

提出一种新型的超宽带全向电小天线,应用折叠技术改变了地板的形状,极大地减小了天线的物理尺寸,方便了实际工程中的安装和携带。设计的天线工作频段为2．55～17GHz,电压驻波比小于2,在频段7～17GHz增益5dBi左右,低频段增益有所下降,但仍大于1dBi。设计过程中,根据频率无关天线（单锥天线）的物理尺寸,通过仿真软件CST建立模型,最后得到的尺寸为37．8mm×60mm。     

Miniature high gain slot-fed rectangular dielectric resonator antenna for IoT RF energy harvesting

Radio-frequency (RF) energy harvesting is a promising candidate for alternative power source that can reduce the dependencies on batteries. However, its power density is very low which makes it crucial to have a high gain antenna to increase the power received by the system. This study presents the design of miniature high gain dielectric resonator antenna for RF energy harvesting application with high figure of merit to increase the power received. Numerical approximation is used to assist the antenna design and modelling. The design focused on three parameters which are the width, length, and height of the dielectric resonator. The performance, electric field density, and the radiation patterns of the dielectric resonator antenna have been observed by varying the design parameters. The effect of air gap to the performance is investigated and it is found that 8.11–13% gain improvement and up to 36% improvement in impedance matching is achieved through incorporating thin air gap between the dielectric resonator. Soda-lime glass with relative permittivity 7.75 is used which allows miniaturization and transparency. Experimental results show reasonable agreement to the simulations. The work shows highest antenna gain with smallest size with high FOM at 5 GHz ISM band compared to previous works.     

对拓式高增益Vivaldi天线设计

为了提高传统对拓式Vivaldi天线在低频段的增益以满足微波探测脑活动穿透力的需求,设计了一种尺寸为100 mm×120 mm×2 mm的对拓式Vivaldi天线。该天线在不改变原天线尺寸的情况下通过在接地层加载圆弧形反射器来改善天线在低频段的辐射特性。结果表明,在1~3 GHz频带内天线的VSWR<2,在工作频带内增益均高于4 dB,相对于未加载圆弧形反射器的情况,频带内增益最大提高了3 dB。对天线进行加工实测,实测与仿真结果吻合良好,使得该天线可以应用于人脑活动探测等领域。     

Cylindrical ring dielectric loaded horizontally polarized omnidirectional antenna for wideband radiation

A wideband horizontally polarized omnidirectional antenna with a cylindrical ring dielectric (CRD) loaded is proposed. Compared with the conventional alford-structure loop antenna (ASLA), the impedance and radiation pattern bandwidths are broadened by loading a CRD to the ASLA with two wing sections. The designed antenna is fabricated and measured, and good performance has been obtained. The measured reflection coefficient is less than −10 dB over the frequency band 1.63–2.8 GHz, i.e., 52.8%, which can cover 2G/3G/LTE band totally. The gain variation in all directions of horizontal plane is less than 1.4 dB in the whole band. The maximum gain is 1.56dBi throughout the operating band and it appears at 1.66 GHz. It is worth noting that the gain is around 1dBi and almost constant from 1.9 GHz to 2.7 GHz. Besides, the designed antenna has a compact size of 0.55λ × 0.55λ × 0.057λ, λ is for the lowest frequency of the operating band.     

Dual band dielectric resonator antenna for wireless application

The proposed technique is an integration of a slot antenna and a dielectric resonator antenna (DRA). This is designed without compromising miniaturisation and efficiency. It is observed that the integration of slot and dielectric structure itself may be merged to achieve extremely wide bandwidth over which the antenna polarisation and radiation pattern are preserved. Here the effect of slot size on the radiation performance of the DRA is studied. The antenna structure is simulated using the CST software. The simulated results are presented and compared with the measured result. This DRA has a gain of 7.1 and 6.3?dBi at 5.7 and 8.1?GHz, respectively, its 10?dB return impedance bandwidth of nearly 4.5% and 5.5% at two resonating frequencies. A total of 98% efficiency has been achieved from the configuration. It is shown that the size of the slot can significantly affect the radiation properties of the DRA and there are good agreements between simulation and measured results.     

一种微带准八木天线的改进设计*

在RamadanA.Alhalabi设计的准八木天线基础上进行了改进设计,采取增加展宽天线带宽的两个寄生贴片和振子耦合枝节和提高天线增益的天线背面引向振子组,减小天线体积的馈线结构等改进措施,从而达到展宽天线相对带宽的目的.使用Ansoft HFSS软件对改进天线进行仿真实验和对实物天线进行测试,结果表明:这种改进型天线结构设计合理,其相对带宽都大于20％ (VSWR≤2),在2.4GHz处的增益都大于10dB,天线具有良好的性能,从而拓宽了该准八木天线的应用范围,而且紧凑的结构和较小的尺寸便于天线组阵.