A Novel Reconfiguration CPW Leaky-Wave Antenna for Millimeter-Wave Application

A novel reconfigurable millimeter-wave leaky-wave antenna is proposed according to the radiation characteristics of periodically loaded coplanar waveguide and simulated by the finite-difference time-domain method. The simulated results demonstrate that the single main beam of this antenna operating at 35.0GHz can scan with small steps in the E-plane from ?90° to 90° except the angle around 0°. The main beam scanning is obtained by the antenna structure reconfiguration with nine discrete states controlled by embedded switches and two feed ports. The antenna is useful for millimeter-wave applications.     

Scanning characteristics of ferrite fed microstrip array antenna

A new ferrite fed microstrip scanning array antenna is proposed which is capable of beam scanning in the azimuthal plane as well as in the elevation plane. The antenna consists of eight microstrip arrays, each having six elements in cascade. The antenna is fed with a ferrite loaded rectangular to circular waveguide transition. The coupling between the feed system and diOEerent arrays is achieved through slots cut in the circular waveguide. Theoretical investigations of the proposed antenna exhibit a beam scanning of ±180° in the azimuthal plane with the help of dc bias and 90° in the elevation plane for ±750 MHz deviation. A scan rate of 0:06° MHz^?1 is achieved for each array antenna in the elevation plane, which makes it suitable for radar. Continuous uniform beam shift is observed during scanning.     

毫米波车地通信的小型化波导螺旋阵列天线设计

高速磁浮列车毫米波车地通信系统要求其车载天线具有小型化、宽频带、圆极化和辐射扇形波束等特点。为更好地满足这些要求,设计一种中心馈电的小型化波导螺旋阵列天线。该天线馈电系统采用同轴波导中心馈电、4路矩形波导并馈的形式,通过改变馈电波导尺寸、耦合探针长度以及末端采用波导同轴转换器等形式,实现了所有单元的等幅馈电;天线单元由低剖面螺旋天线构成,采用顺序旋转技术改善天线的圆极化性能。利用全波电磁仿真软件设计了一款中心频率为38 GHz的28单元波导螺旋阵列天线,并进行了实验测试。测试结果表明：在37~39 GHz频带范围内,天线驻波比小于1.41,增益大于21.7 dB,轴比小于3.6 dB,俯仰面波瓣宽度为4.5°~4.7°,方位面波瓣宽度为29°~29.7°,满足毫米波车地通信系统车载天线的设计需求。     

Plasma travelling wave antenna

The possibility of using plasma column as linear travelling wave antenna is studied. It is shown that surface current waves propagating in plasma column of finite length are a source of paraxial electromagnetic radiation of decimeter band. Influence of dielectric waveguide, which surrounds cold isotropic plasma, on dispersion properties of plasma column is investigated. The corresponding dispersion equation for eigenwaves of circular dielectric waveguide filled with plasma is derived and solved numerically. Plasma and waveguide parameters are determined under which the surface wave slowing-down is close to unity leading to antenna’s radiation primarily in axial direction. It is shown that in case of plasma density around 10¹²−10¹³ cm⁻³ dispersion of the considered wave is close to dispersion of waves propagating in metal travelling wave antenna.     

一种基于5G应用的圆极化微带相控阵天线

本文提出一款应用于5G频段,可实现方位面±40°波束扫描的圆极化微带相控阵天线。该相控阵天线单元是由矩形贴片、上下介质板、缝隙耦合馈电结构、金属反射板构成。利用切比雪夫综合法的一分八不等分功分器实现相控阵天线的馈电形式。测试结果表明,阵列天线的驻波比带宽为3.25 GHz～3.69 GHz,端口隔离度大于25 dB,扫描过程中增益最大为21 dB,增益衰落小于3 dB,最大扫描角处轴比为2.89 dB。该天线具有低剖面、高隔离度、高增益以及良好的波束扫描性能等优点。     

基于超材料结构的定频波束可调天线设计

提出了一种新颖的波束可调天线。该天线辐射单元采用加载电容的超材料结构,相较于传统波导裂缝阵列天线的辐射缝隙,超材料辐射单元的尺寸缩小了76%;天线采用蚀刻有超材料结构的Rogers RT5880印刷电路板(PCB)作为天线辐射面,通过调整加载在超材料单元上的电容来调整波束指向。天线的测试结果与电磁仿真软件仿真结果接近。测试和仿真结果表明,天线工作在频率15 GHz,最大增益为11 dBi,辐射效率为80.8%,波束可调天线实现了-28°,-20°,-12°,-6°,6°, 13°和24°七种不同波束指向。     

Source primaire multi-éléments et matrice de commutation associée pour satellite de télécommunication utilisé en mode AMRT

This paper describes a 12 GHz primary feed system designed for a scanning spot-beam transmitting antenna system operated in time-division multiple access (tdma) mode. The feed is made of three main parts: a radiating cluster consisting of seven horn elements, apin diode switch device which performs electronic scanning of the beam by successively activating the seven radiating elements, arf sensing waveguide network. The antenna system features are designed to optimize the gain throughout the coverage. A minimum directivity above 46 dB (without considering power losses due to the switch device) in a 1.35° coverage (corresponding to France) is expected from measured characteristics of the primary feed. This is corresponding at a 4 to 5 dB improvement upon a global beam system.     

Research on dual-polarized circular waveguide antenna fed by L-shaped probes

This paper researched a kind of dual-polarized and cylindrical waveguide antenna fed by two L-shaped probes at the antenna bottom. The designed antenna was composed of two orthogonal L-shaped coaxial probes and a cylindrical waveguide cavity. The two orthogonal field structures were excited and the dual-polarized radiation mode was formed. The feeding cables of two polarization ports went through the bottom of the cylindrical cavity and were connected with the microwave adaptors. The bottom feeding structure was suitable to constitute a planar antenna array. The electromagnetic simulation and optimization design of the proposed antenna were carried out by using the full wave electromagnetic simulation technique, and the simulation results showed that the isolation between two polarization ports were more than 20 dB within the frequency range of 4.8–5.4 GHz. At the center frequency, the cross-polarization levels of radiation pattern were lower than −21 dB at the boresights and the beam width of radiation patterns at E-plane and H-plane were more than 70° for two polarization ports. The designed antenna in this paper was fabricated and measured. The measurement results indicated that the designed antenna achieved anticipated radiation performances and design effectiveness of the dual-polarized antenna in this paper was proved. The dual-polarized and cylindrical waveguide antenna is suitable for some application fields such as dual-polarized array radar. The research results in this paper can provide a technical basis for the practical engineering application.     

Peano分形加载单极子辐射性能的研究

对有限地板尺寸和介质填充情况下Peano分形加载单极子天线的辐射特性进行了研究.利用HFSS分析了地板尺寸和填充介质材料对天线反射系数、辐射方向图和增益的影响.仿真表明:随着地板尺寸的减小,天线的阻抗带宽和增益明显减小,H面方向图变化不大,而E面方向图的半功率波束宽度增大,波束仰角减小;填充材料的介电常数过大会导致天线性能的恶化.在分析研究的基础上,设计并研制了地板尺寸为220mm×220mm的一阶和二阶Peano分形加载单极子天线.天线分别实现了45°和36°的波束仰角,50°和45°的半功率波束宽度.仿真与实测结果均表明凋节地板尺寸是控制Peano分形加载单极子天线E面半功率波束宽度和波束仰角的一种简单而有效的方法.     

Antennas and waveguides for far-infrared integrated circuits

Antennas and waveguides for the wavelength range 0.1-3 mm are considered. Emphasis is placed on those designs which lend themselves to integration with each other and with other components such as diodes. The general properties of FIR antennas are reviewed. A novel silicon waveguide antenna is discussed, and its design, simulation, fabrication, and performance at 119 μm are described. This antenna has a highly symmetrical, single-lobed beam with 3 dB beamwidths of 35 and 38° in theE- andH-planes, respectively. The gain (measured in microwave simulation) is 12.8 dB. This antenna is well suited for integration with Schottky diodes. The related subject of FIR waveguides is discussed. Experiments with metal transmission lines at 119 μm are described and dielectric guides related to the waveguide antenna are also considered. Using components such as these it may soon be possible to construct receiver front ends for this wavelength range in integrated-circuit form.     

基于液晶的太赫兹反射式波束扫描天线

提出了一种基于液晶的太赫兹电控反射式移相器及其构成的波束扫描阵列天线。通过采用液晶调控的开槽结构移相器,解决了液晶调控过程中谐振层覆盖面不足造成的液晶取向不均、边缘效应和饱和电压增大等问题。设计了工作在380 GHz三开槽的移相器,对谐振频点的表面电流分布和谐振频点进行了仿真分析。数值计算结果表明当液晶相对介电常数在2.47~3.26范围内变化,377~392 GHz频率范围内移相器能够实现360°的相移。采用三开槽结构反射相移单元,设计了工作于380 GHz的电控波束扫描阵列天线,实现了30°范围内的一维波束扫描,主瓣增益大于20 dBi。     

An E-plane ferrite loaded simple waveguide radiator

Experimental investigations were conducted to examine the effect of dielectric loading on a ferrite loaded waveguide radiator (notch antenna). The antenna was made by symmetrically tapering an X-band waveguide. A cylindrical ferrite post was disposed at the apex of the notch and it was biased with a dc magnetic field. The antenna was tested for several notch angles namely 140/spl deg/, 120/spl deg/, 90/spl deg/, 80/spl deg/, 60/spl deg/ while ferrite was loaded with several dielectric sleeves, such as wood, polymer, pyrex. The dielectric loading with high permittivity material is found to give better radiation and scanning characteristics. The radial thickness of the dielectric ring is observed to affect the radiation.     

基于复合左右手材料的圆柱共形漏波天线设计

提出了一种基于复合左右手材料的平衡式圆柱共形漏波天线。天线单元由圆柱共形介质波导构成,通过在波导上表面蚀刻矩形缝隙槽结构,在引入串联电容的同时实现电磁波能量的连续泄漏,从而得到所需要的辐射特性。同时在波导结构中采用金属化通孔,引入并联电感, 实现了电磁波的左手传输特性。所设计的天线在平衡频点 15.6 GHz 处具有良好的边射特性。所提出的复合左右手漏波天线的阻抗带宽为 4.3 GHz(13.5~17.8 GHz),在天线阻抗带宽范围内天线主波束可以从-57°连续扫描到+30°。     

V频段圆柱龙伯透镜天线设计

设计并实现了一种V频段圆柱龙伯透镜天线.在平行平板波导间,根据龙伯透镜原理与介电常数等效原理,推导出了圆柱龙伯透镜天线的理论设计公式,并结合商业仿真软件高频结构仿真器(HFSS)仿真分析和优化,完成天线设计.仿真结果表明,该V频段圆柱龙伯透镜天线增益为21.4 dBi,波束宽度为1.56o,副瓣电平为-14.7 dB.根据设计结果,加工和测试验证V频段圆柱龙伯透镜天线的可实现性,实测结果表明,该天线增益为20.1 dBi,波束宽度为1.60o,副瓣电平为-11.1 dB,天线效率为45.7％,说明该天线具有一定的工程应用价值.     

一种宽带双极化波导阵列天线的设计

设计了一种适用于雷达、通信等领域的宽带双极化波导阵列天线。天线的垂直极化信号通过波导阻抗变换直接馈电实现,水平极化信号通过由垂直极化信号馈电、缝隙耦合的方式实现。设计的阵列天线在12 GHz～15 GHz的频带内驻波比小于2,交叉极化低于25 dB,单元增益在带内大于8 dB,波束宽度大于60°。加工天线后实测结果与仿真结果吻合,该种阵列天线既适合固定波束阵列天线,又适合具有相扫功能的阵列天线。     

Analysis of the characteristics of NRD waveguides loaded with periodic metallic strips by using the method of lines for millimeter wave filter and antenna application

In this paper, the propagation characteristics of NRD waveguide loaded with periodic metallic strips are analyzed in terms of the method of lines. Numerical results show that such structures are most suitable for millimeter wave bandstop filter and NRD waveguide beam scanning leaky wave antenna application.     

新型低剖面石墨烯THz 天线研究

提出了一种新型石墨烯THz天线,该天线由金属波导和周围多个石墨烯单元构成,相比于传统的金属天线,具有馈电简单、低剖面的特点。由于石墨烯在THz频率具有负的电导率虚部,因此会激发其局域表面等离激元共振。电磁波通过波导口向外辐射过程中,波导和天线单元之间强烈耦合,形成集体的电磁波振荡,由此天线单元之间保持了良好的相位一致性,最终使得远场的增益比单波导口增益增加了6.5dB,波束宽度则减小至21.2°,有效提高了天线的性能。通过改变石墨烯的偏置电压或者掺杂浓度还可以改变其工作频率,形成可调谐的石墨烯THz天线,未来可以应用于THz通信等方面。     

一种基于介质加载的地球覆盖波束天线设计

地球覆盖波束天线为低轨卫星与地面终端之间的数据传输建立了通道,文中研究了一种新型的介质 加载地球覆盖波束天线。基于介质加载的方法,文中提出了一种圆极化地球覆盖波束天线设计,该天线由馈电网 络、馈源和介质三部分组成,介质包括底部圆柱部分和顶部半球部分,馈源集成于介质内部。设计的地球覆盖波束 天线工作在C 波段,轴向0°~64°范围内增益在0 dBic 以上,40°方向增益为5. 2 dBic。天线尺寸紧凑,辐射波束具有 较好的空间截止特性,可满足立方星应用。     

Appling Weighted Thinned Linear Array and Pattern Reconfigurable Elements to Extend Pattern Scanning Range of Millimeter Wave Microstrip Phased Array

A weighted thinned linear array with pattern reconfigurable antenna elements is proposed to overcome the disadvantages of traditional millimeter wave phased arrays, such as, narrow scanning range, high grating lobes. The developed array can scan its main beam from φ = -76° to 76° in H-plane and has 3 dB beam coverage from φ = -88° to 88° with low grating lobes by shifting two operating states of the elements and adjusting the feed phases.     

The U-Band Pattern Steerable Active Patch Antenna

Combing the active antenna concept with the reconfigurable antenna technique, a pattern steerable active patch antenna is presented and designed in this paper. A Gunn diode is used to generate the millimeter wave signal and loaded at the centre of the patch antenna. This antenna system has a stable oscillation frequency f : 44.0GHz and operates as a quasi-Yagi patch antenna. The radiation patterns of the antenna can scan in the whole horizontal plane with 3-db beam width by using four reconfigurable states and the radiation main beam of each state directs to the elevation angle 59° in the elevation-plane. The antenna can be applicable to the millimeter wave half-duplex communication and identification systems.