X频段介质加载圆极化喇叭天线设计

设计了一款基于全介质极化器的X频段圆极化喇叭天线。该全介质极化器加载在线极化喇叭天线的前端,将线极化波转换为圆极化波,并有效辐射出去。同时,该全介质极化器还将天线的实测增益提高了约2 dB。天线的测试结果与仿真结果吻合较好。该天线在X频段（8~12 GHz）的实测S11均小于-10 dB,实测轴比在X频段内均小于3 dB,表明该圆极化喇叭天线具有宽带高增益特性。并且,该全介质极化器使用3D打印技术制作,具有加工简便、成本低的优点。该天线可应用于雷达、跟踪制导、卫星通信系统等领域。     

小型化缝隙加载圆极化及宽带微带贴片天线设计

提出了一种十字形缝隙加载的小型宽带及圆极化微带贴片天线的设计方法。该天线通过在方形贴片上加载一个大尺寸的十字形缝隙实现天线的尺寸缩减,介质基片采用由FR4和空气层组成的层叠结构,在缝隙中嵌入L型枝节,只需通过调整枝节上同轴线馈电点的位置来获得圆极化或宽带阻抗匹配。ANSYS HFSS仿真分析表明,天线的圆极化带宽（AR≤3 dB）为1.7%,阻抗带宽（VSWR≤2）为5.8%,天线在宽带范围内具有稳定的增益,峰值增益为7.8 dB,同时贴片面积缩减了52.3%。改变馈电点的位置可调节两个谐振频率使天线阻抗带宽达到9.4%,比传统的微带贴片天线阻抗带宽提高了114%。     

W波段双圆极化天线研究与设计

毫米波圆极化天线具有减少极化失配、抑制多径干扰的特性,在恶劣环境中具有更好的稳定性,是提升通信系统性能的重要器件.利用喇叭天线和隔板极化器设计了一款双圆极化天线,并在天线和极化器的连接处采用电磁带隙结构,可以有效减小装配误差对天线性能的影响.实测结果显示,所加工的天线可应用于W波段通信系统,其工作带宽覆盖95 GHz到...     

一种新型双频双圆极化复合微带天线设计

针对空间微波能量收集的应用场景,提出了一种微带线行波激励的双端口双频双圆极化复合微带天线。该天线由一个工作在低频段的微带圆环和一个工作在高频段的微带圆片复合而成,分别由两种不同的正交十字缝隙耦合馈电,采用微带线级联依次相差90°顺序旋转四馈电实现圆极化,通过对称性结构设计,分别从两个不同端口输入获得双圆极化性能。实验结果表明：在880～960 MHz和1.85～2.45 GHz频带内S11<-10 dB,阻抗相对带宽分别为8.7%和30%;在885～920 MHz和1.86～2.43 GHz频带内轴比小于3 dB,圆极化相对带宽分别为4%和29%;天线的方向性在工作频段内良好,在低频段增益达到5.4 dB,在高频段增益达到7.7 dB。该天线结构紧凑且加工简单,为双端口双频双圆极化天线的研究与设计提供了新思路。     

采用弧形耦合馈电的宽带圆极化陶瓷天线

提出了一种以陶瓷为介质的小型化的宽带圆极化环形贴片天线.该天线具有较大的圆极化带宽,作为卫星接收天线同时接收多个卫星系统发出的导航信号.天线的辐射和馈电相互独立并且不受环境的干扰.测试结果表明:天线的阻抗带宽和轴比带宽分别为28%和32%.增益最大值为3.9dBic.与传统的半波长贴片天线相比,本天线的体积缩小了89.6%,实现了天线小型化.该天线还具有较大的半波束功率宽度,可以覆盖倾角较低的卫星,它在卫星数目较少时,对建卫星系统有积极的使用价值.     

相控阵天线用极化控制元件

每一个由线极化波馈电的相阵天线的极化波的相位和极化旋向依照由非互易圆极化器（NRCP），法拉递旋转器和一个旋器转的非互易圆极化器的级联关系而变换，法拉递旋转器和旋转极化器的控制线圈决定了传输波的相移量和极化旋转量。     

宽带高增益圆极化天线

设计了一种宽带高增益圆极化天线。天线采用双同轴线激励以及威尔金森功分器和90°相位比较器的馈电网络形式实现了天线的宽带圆极化特性。该馈电网络形式能在较宽的频带范围内保持稳定的幅度和相位。通过在蝶形天线外围引入方形环,增加了天线的有效辐射面积,从而显著提高了天线的增益。测试结果显示,该圆极化天线VSWR<1.5的阻抗带宽达到63.6%,3 dB轴比带宽达到66.7%,且在1.1~1.6 GHz频段范围内,右旋圆极化增益＞9.4 dB。     

基于对称哑铃型的双圆极化微带天线设计

小型化和宽轴比带宽是双圆极化天线设计领域的研究热点。文章设计了一款馈电结构简单,天线尺寸较小的双圆极化微带天线。天线利用同轴电缆双端口馈电,在介质板上下两层对称分布的两个哑铃型贴片,分别辐射右旋圆极化(RHCP)波和左旋圆极化(LHCP)波。在天线的基础上,添加寄生贴片,通过天线互耦作用,改善了天线的匹配和增益情况。经仿真分析,此天线实现了48%的工作带宽和13%的轴比带宽,具有工作频带宽,可实现双圆极化,结构简单以及尺寸小型化的特点。     

基于超表面的圆极化印刷偶极子天线研究

利用一种以双头箭头作为结构单元的反射型极化旋转超表面,设计了圆极化的印刷偶极子天线。通过将该超表面加载在普通印刷偶极子天线的下方,使线极化的偶极子天线辐射圆极化波。测试表明,天线的圆极化工作带宽为6.96 GHz到7.13 GHz。在7.04 GHz处,垂直方向上的轴比达到约1 d B。该天线有着较好的圆极化效果,并且实现了低剖面以及小型化。     

一种基于电调移相器的可重构天线

设计并实现了一种基于反射式移相器的极化可重构天线。该天线使用一对交叉摆放的领结型振子作为辐射单元,并在馈电网络中通过两路移相器调整双馈端口间的相位差实现线极化、左旋圆极化和右旋圆极化模式之间的切换。通过加载匹配枝节的方法扩展了反射式移相器的移相范围,提高了移相器的移相精度,降低了天线圆极化模式带内的轴比。所设计天线的中心频率为5.4 GHz,在线极化模式下10 dB 阻抗带宽为990 MHz,在圆极化模式下10 dB 阻抗带宽分别为760 MHz 和850 MHz,3 dB 轴比带宽分别为510 MHz和480 MHz。该天线在频带内具有稳定的波束方向图,其平均增益为5.3 dB,并且具有27 dB 的主极化-交叉极化隔离。最终的实测结果与仿真结果基本一致,表明该天线具有良好的性能。     

The slot-coupled hemispherical dielectric resonator antenna with a parasitic patch: applications to the circularly polarized antenna and wide-band antenna

The aperture-coupled hemispherical dielectric resonator antenna (DRA) with a parasitic patch is studied rigorously. Using the Green's function approach, integral equations for the unknown patch and slot currents are formulated and solved using the method of moments. The theory is utilized to design a circularly polarized (CP) DRA and a wide-band linearly polarized (LP) DRA. In the former, the CP frequency and axial ratio (AR) can easily be controlled by the patch location and patch size, respectively, with the impedance matched by varying the slot length and microstrip stub length. It is important that the AR will not be affected when the input impedance is tuned, and the CP design is therefore greatly facilitated. For the wide-band LP antenna, a maximum bandwidth of 22% can be obtained, which is much wider than the previous bandwidth of 7.5% with no parasitic patches. Finally, the frequency-tuning characteristics of the proposed antenna are discussed. Since the parasitic patch can be applied to any DRAs, the method will find applications in practical DRA designs.     

Bandwidth Enhancement of Circularly Polarized Dielectric Resonator Antenna

Axial‐ratio (AR) bandwidth enhancement is achieved for a circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) using a wideband hybrid coupler (WHC) combined with dual probe feed. The presented WHC, comprised of a Wilkinson power divider and a wideband 90° shifter, delivers good characteristics in terms of 3 dB power splitting and consistent 90° (±5°) phase shifting over a wide bandwidth. In turn, the proposed CP DRA, for the employment of the WHC, in place of conventional designs, provides a significant enhancement on AR bandwidth and impedance matching. The antenna prototype with the WHC exhibits a 3 dB AR bandwidth of 48.66%, an impedance bandwidth of 52.5% for voltage standing wave ratio (VSWR) ≤ 2, and a bandwidth of 44.66% for a gain of no less than 3 dBi. Experiments demonstrate that the proposed WHC is suitable for broadband CP DRA design.     

Circularly polarized antenna array with a new sequential phase feed network utilizing directional coupler

This is a presentation of a new design of circularly polarized (CP) antenna array having a wide axial ratio (AR) bandwidth and high-gain. It uses an innovative feed network which consists of compact directional couplers and a delay line describing a new kind of sequential phase (SP) feed network. Furthermore, in this work, we report and discuss the features of the feed network and single element. In the following, the single element antenna and the 2 × 2 CP antenna array are designed, prototyped and tested. The antenna array is designed by a multilayer microstrip structure with a compact size of 75 × 52 mm². Moreover, a metal reflector is utilized to enhance the antenna gain and achieve a unidirectional radiation pattern over the operating frequency band. According to the experimental results, the CP antenna array has a return loss (RL) bandwidth of 2.42 GHz (5.83–8.25 GHz), AR bandwidth of 1.11 GHz (6.76–7.87 GHz), and peak gain of 12.15 dBic. It seems that the performance of the proposed design is admirable for C-band frequency.     

采用口径耦合馈电的5.8GHz天线的设计

文章根据不停车电子计费系统（ETC）的国家标准（GB/T 20851.1-2007）要求,设计出了一款采用圆形贴片的右旋圆极化微带贴片天线,并对其馈电结构进行了传输线等效模型的理论分析。该天线采用十字型缝隙口径耦合馈电方式,结构简单,可作为ETC系统的车载单元（OBU）天线使用。经实验证实,此种类型天线不但易于产生圆极化波,而且可以得到比较理想的阻抗带宽、圆极化带宽和增益等以满足设计要求。     

Cavity-Backed Miniature Wideband UHF Circular Polarized Antenna With Textured Dielectrics

Use of high permittivity dielectrics with antennas is known to reduce their operating frequency but also introduces side effects such as reduced gain and bandwidth. This paper presents a miniaturization scheme for a 15 cm (6 inch) square circularly polarized (CP), cavity-backed antenna using textured dielectric loading and a folded metallic strip feed. The proposed design has an operational frequency f, around 500 MHz implying a linear size of 0.25lambda₀. The challenge in designing such a small size antenna is to increase bandwidth (10-15%) while retaining a gain of 2-4 dBi. By carefully positioning high permittivity textured dielectrics within the aperture in conjunction with shape design, we show that bandwidth and gain are retained as compared to comparable size antennas in the literature. As part of our design, we present parametric studies through computer simulations and a prototype antenna is fabricated and measured for verification     

A broadband circularly polarized cavity-backed Archimedean spiral array antenna for C-band applications

In this letter, a new configuration of sequentially rotated circularly polarized (CP) array antenna with a modified gain is investigated. In order to realize the presented antenna, four Archimedean spiral radiators are applied on a substrate, backed by a circularly slotted ground plane. Also a combination of 180° rat-race coupler and 90° branch-line couplers prepare the employed feeding network in this study. Furthermore, cavity-backed structure is utilized to enhance the antenna gain and achieve a directional radiation pattern over the operating frequency band. This configuration also extends the return loss (RL) and the axial ratio (AR) bandwidths, simultaneously. According to the experimental results, the 2 × 2 CP array antenna has RL bandwidth of 64.28%, AR bandwidth of 54.28%, and peak gain of 10.84 dBic. The close correspondence between the measured and the simulated results validates the proposed design.     

SIW cavity-backed circularly polarized square ring slot antenna with wide axial-ratio bandwidth

In the proposed work, Substrate Integrated Waveguide (SIW) cavity-backed circularly polarized slot antenna for wideband operation is proposed. A square-ring-slot is etched on the top of the SIW cavity, used for radiation To generate the circularly polarized (CP) wave, the slot is placed slightly offset from the centroid of the cavity. By finely optimizing the antenna dimensions, it exhibits a wide axial-ratio (AR) bandwidth of 789 MHz (7.1%) ranging from 10.64 to 11.45 GHz. Moreover, the radiating slot is excited by an SIW based feed by an inductive window, which lead to a wide impedance matching over 1.74 GHz ranging from 9.92 to 11.67 GHz. Due to the SIW cavity-backing structure, the antenna offers unidirectional radiation patterns while maintaining a low-profile and planar compatibility. To validate the proposed design, the antenna is fabricated and experimentally tested in terms of reflection coefficients, AR, gain, and radiation patterns. The simulated and measured results reveal good mutual agreement. Moreover, the proposed antenna is very useful for wideband applications operating in X-band (8–12 GHz)     

一种新颖的宽带圆极化单极天线

该文设计了一种新颖的宽带圆极化单极子天线,该天线采用微带馈电模式。天线由C型贴片和改进的地板组成,整个天线尺寸仅为25×25×1 mm3。通过在C型贴片上切角和在地板上增加三角形微扰结构,可以有效增加天线的阻抗带宽和轴比带宽。该文给出了天线的设计流程,从表面电流分布分析了圆极化天线的工作机理。加工了天线实物,并对其进行了测量。仿真和实测结果表明天线具有超宽的阻抗带宽和轴比带宽。天线的工作频带为4.35～12 GHz(相对带宽为93.6%),3 dB轴比带宽为4.15～11.8 GHz(相对带宽为95.9%)。测量了天线的辐射性能和增益特性,实测结果与仿真结果吻合较好,证明了该天线的有效性。该天线可以应用于超宽带无线通信系统和卫星通信系统中。     

双频带隔板极化器

介绍了一种双频带隔板极化器的设计思路及其应用实例.这种极化器应用了隔板极化器的双频带特性,在一个很宽的频带内实现了圆极化性能,轴比性能良好,且体积小、重量轻,可以在带宽比较窄的前提下实现收发共用,解决了一些小型天线对微波网络重量和体积限制的问题.     

脊波导缝隙圆极化天线的设计*

设计了一种新型脊波导缝隙圆极化天线。在脊波导宽边开并联纵缝,从波导耦合电磁波至其上方的四脊波导圆极化器,实现圆极化辐射。采用脊波导不仅减小了单元尺寸,更改善了天线的带宽性能。重点研究了四脊波导圆极化器对相互垂直的两辐射场分量的影响,优化单元的轴比特性。在提取单元谐振电导的基础上,设计了工作在10GHz 的1×10 圆极化波导缝隙阵列。对天线实物测试得到中心频率处的增益为16.8dB,第一副瓣电平为 25dB,阻抗带宽约为8.5%,相对轴比带宽(AR臆3dB)约为3.2%。