一种具有宽角轴比特性的圆极化天线

分析了微带圆极化天线的工作原理,提出了一种双层电磁耦合型馈电结构以取代传统的馈电结构.通过优化L型微带馈电形状、馈线与辐射单元间的间距以及馈线阻抗匹配等措施,实现了一种具有宽角轴比特性的微带圆极化天线,并对其样机的增益、轴比和电压驻波比进行了测试,测试结果表明天线性能达到了预期研究目标.     

LTCC宽频圆极化环形微带贴片天线研究

设计了一种低温共烧陶瓷( LTCC)宽频带圆极化环形微带贴片天线.该天线采用环形辐射贴片结构,在环形内部利用L型匹配支节连接以拓展带宽.通过使用威尔金森功分器加移相器对辐射贴片馈电,使耦合馈电端口的正交电场相位差90.来实现微带天线的圆极化.该天线设计剖面厚度仅2.4 mm.仿真结果显示该天线工作于1.268 GHz时,实现阻抗带宽超过80 MHz,天线的轴比小于1.5 dB且增益达到4.9 dB.实测结果与仿真结果相近.     

具有稳定相位中心的三馈点圆极化微带天线

介绍了一种具有稳定相位中心的圆极化微带天线。理论分析证明：采用幅度相等,相位相差120°的三馈电方式,圆形微带天线能获得圆极化辐射特性。中心对称的三馈点设计,天线可获得很高的相位中心稳定度。仿真结果显示：此天线相位中心的稳定度小于1 mm.测试结果表明：在2.18~2.66 GHz频带内该天线轴比小于3 dB,相对带宽19.83%。     

Ferrite‐based wideband circularly polarized microstrip antenna design

In this paper, a wideband, circularly polarized patch antenna is proposed that leverages the unidirectional resonant modes of a circular patch mounted on top of a grounded dielectric‐ferrite substrate. The proposed antenna is fed via the proximity coupling method and several parasitically coupled patches are placed on a dielectric superstrate to enhance the impedance bandwidth of the antenna. The resonant modes of the structure rotate only in the clockwise or counter clockwise directions. In the frequency range where the effective permeability of the ferrite layer is negative, the resonance frequencies of these modes differ significantly, which produces a large axial ratio (AR) bandwidth. For the proposed antenna, the numerical results show the 10 dB impedance bandwidth to be around 44% and the 3 dB axial ratio bandwidth to be higher than 64%.     

一种新型宽波束圆极化微带天线的设计

设计了一种新型宽波束圆极化微带天线,该天线采用四探针馈电,馈电网络由威尔金森功分器和传输线移相器组成,使四个馈电探针的相位依次相差π/2,实现了右旋圆极化辐射。通过Ansoft HFSS仿真结果表明：该微带天线结构简单、极化纯度高、全向性能好、轴比小于3dB的圆极化带宽达到27.7%,高于一般的微带圆极化天线（轴比小于3dB带宽约为15%）。天线可以很好地满足GPS通信的技术要求,也可用于无线局域网。     

E-shaped patch with reactive impedance surface for high gain and broadband circularly polarized antenna

A low-profile circularly polarized (CP) antenna with high gain and broad bandwidth is aimed at 5-GHz Wi-Fi applications using a symmetrical E-shaped patch. Initially, the radiating element is modeled as a symmetrical E-shape. An array of 4 × 4 rectangular patches are arranged periodically to make up a reactive impedance surface (RIS) structure. Furthermore, the RIS structure is deployed in the middle of a symmetrical E-shaped radiating patch and a perfect electric conductor (PEC) ground plane. As a result, the broadband CP is achieved with high gain. The above-mentioned combinations have achieved a −10-dB reflection coefficient bandwidth of 21.4% (4.92–6.1 GHz) and a 3-dB axial ratio (AR) bandwidth of 15.5% (5.25–6.1 GHz), and the antenna has attained a gain of 7.45–7.53 dBic.     

单点馈电高增益圆极化三角形微带贴片天线设计

提出了一种单点同轴线馈电小型化高增益圆极化三角形微带贴片天线的设计方法。通过在三角形贴片的中心开一个十字形槽获得圆极化及尺寸缩减,同时在接地板上开三个同尺寸三角形槽提高天线的增益,通过调节三角形槽的尺寸在保持圆极化的情况下准确调节天线的谐振频率。HFSS仿真数据表明,当天线工作于2.43 GHz时,阻抗带宽和圆极化带宽分别为120 MHz(4.9%),30 MHz(1.2%),增益为3.5 d B。与传统的小型化方形贴片天线相比,该天线具有更小的贴片面积和更宽的工作带宽。     

一种全向圆极化微带天线

介绍了一种平面结构的全向圆极化微带天线。天线由两个带有简并分离单元的矩形贴片组成，两个贴片背靠背地分布在共面波导的上、下两面。天线基片宽度较窄，导致天线在方位面内实现全向辐射。设计并实测了一个工作于Ku波段的天线，实测的阻抗带宽达到5．4％，天线在方位面的圆极化轴比均小于2．8dB。该研究为下一步进行毫米波全向圆极化天线的研究奠定了基础。     

一种宽频宽角圆极化一维相扫天线阵

基于改进型Vivaldi天线单元,采用4单元十字交叉组合构成圆极化天线,并通过增加耦合金属立柱改善天线轴比,设计了一种超宽频宽角覆盖圆极化直线阵。该天线在1.25-4.1 GHz频段电压驻波比(VSWR)小于2,在1.6-3.6 GHz频段轴比小于3 dB,在垂直扫描方向具备宽角覆盖能力,具备较高的工程应用价值。     

X波段二维宽带宽扫背腔微带天线

设计了一种X波段背腔微带天线,采用探针和口径耦合相结合的馈电方式实现了小单元间距下单层微带贴片的宽带工作,并弱化了馈线寄生辐射对方向图的扰动。设计加工了8×8单元的天线小阵。实测结果表明,该天线在设计要求的2GHz带宽内驻波小于1.5,驻波小于2的相对带宽25%;方向图测试结果表明实现了方位向45°、俯仰向30°的扫描,增益22.8dB,天线效率大于80%,可满足二维宽带宽扫瓦片天线的实际应用需求。     

A circularly polarized slot antenna for high gain applications

A coplanar waveguide fed slot antenna for wideband circular polarization is designed and experimentally validated. The rectangular slot is excited using a stepped feed line terminated on a circular disc shaped tuning stub. To obtain circular polarization, inverted L-shaped strips are attached to the ground plane at the opposite corners while a rectangular slit is cut in the circular disc. The combined bandwidth (3-dB axial ratio and 10 dB impedance matching) achieved is 48% (4.35–7.1 GHz) under simulation and 40% (4.75–7.1 GHz) in measurement. The gain of the antenna is next enhanced by the application of a double layered square loop frequency selective surface. The frequency selective surface is used as a reflector placed beneath the antenna at an optimum distance. An improvement of about 4 dB is seen in the measured peak gain over most of the operating band. Experimental results are presented to characterize the antenna and the frequency selective surface and they are found to be in good agreement with the simulated results.     

一种新型单馈点宽带圆极化微带天线的设计

介绍了一种新型单层单贴片圆极化微带天线。该天线采用同轴线单点馈电,通过在圆形贴片上开C型缝的方法实现圆极化辐射并同时展宽了天线的阻抗带宽。仿真结果显示,该新型天线工作于C波段时,3dB轴比带宽为2.6%（124 MHz）,VSWR〈2的阻抗带宽达到10%（477 MHz）。证明了在贴片上开C型缝是展宽带宽和实现圆极化的有效方法。     

双频圆极化微带天线小型化设计

研究了一种单馈条件下双频圆极化微带天线的设计方法,通过开槽的方式实现了小型化,采用辐射边加载实现了阻抗带宽的展宽,采用电磁仿真软件HFSS进行了仿真,得到了天线的VSWR、AR以及增益等指标,对这些指标进行分析后,证明了该天线设计方法的可行性与正确性。     

一种新型布局的圆极化微带天线阵优化设计

提出了一款高增益低副瓣新型圆极化微带天线阵。单元天线采用叠层切角圆极化微带结构,通过八边形边界布局和顺序旋转交叠组阵技术,实现了天线阵方向性图的对称性和圆极化辐射性能的最优化;馈电网络采用威尔金森功分器和最大平坦式阻抗变换器实现不等功分宽带阻抗匹配,通过改进馈电方向寻求对称结构,简化了馈电网络的设计。制作了天线阵实物并进行了测量。测试结果表明:天线在3.2~4.6 GHz频段内S₁₁<-10 dB,阻抗相对带宽36%;在3.8~4.5 GHz频段内顶点轴比小于3 dB,圆极化相对带宽17%;在4~4.4 GHz频段内天线增益均在15 dB以上,最高增益达17 dB。     

Circularly polarized co-designed filtering annular slot antenna

In this paper, a compact circularly polarized co-designed filtering annular slot antenna (ASA) is proposed. The antenna comprises a distributed capacitor-loaded annular slot radiator to produce circular polarization (CP) radiation, which is seamlessly integrated with a microstripline bandpass filter (BPF) to enhance out-of-CP-band suppression. Two tightly coupled arc branches protruding into the annular slot are used to provide the required perturbation capacitance. The filter is designed by employing three concentric arc-shaped coupled microstripline resonators. The ground plane is shared by the annular slot radiator and the filter to reduce size occupation. It is found that the proposed antenna can not only yield high frequency selectivity, but also obtain widened CP bandwidth under the assistance of the filtering circuit. An antenna prototype has been fabricated and measured, showing that the antenna achieves a 10 dB return loss impedance bandwidth of around 13.7%, enclosing a 3 dB axial ratio (AR) bandwidth of more than 10.6%. Details of design considerations and experimental results are presented and discussed.     

一种以空气为基板的圆极化微带天线的设计

设计了一种以空气为基板的超高频（UHF）圆极化矩形微带天线。该天线通过在微带贴片四周与中心开槽,减小了天线尺寸,实现天线圆极化的性能。进一步研究了天线的参数对圆极化性能的影响,通过天线参数的优化,使天线达到了良好的圆极化性能。     

宽带宽波束圆极化微带八木天线

提出了一种具有两级双贴片引向器结构的双馈圆极化微带八木天线.通过移除部分接地板结构,有效地增大了天线在端射前向的圆极化增益和波束宽度.等幅异相的同轴双馈模式使得该天线具有较宽的工作频带.数值仿真与实验结果表明:该天线同时满足驻波比R vsw≤1.5及端射方向轴比RA≤3 dB的相对带宽为11％.天线在俯仰面仰角0°至80°的范围内具有良好的圆极化辐射特性,方位面主极化半功率波瓣宽度达到88°,同时具有较高的辐射前后比.良好的工作特性表明此天线可作为机载或弹载通信的备选天线.     

低剖面可承载UHF/L双频共口径圆极化定向天线

为了满足毫米波高密度、宽角扫描共口径相控阵天线对高性能、紧凑型天线单元的需求,提出了一种宽带Ku/Ka共口径天线单元设计方案. Ku频段双极化天线采用“十”字形贴片作为辐射体,一对正交放置的缝隙用于激励两个正交工作模式. Ka频段天线为探针馈电的磁电偶极子天线,加载的4个小贴片起调节匹配和方向图的作用. 同时,Ka频段天线对Ku频段天线起寄生加载作用,在有效降低Ku频段天线谐振频率的同时扩展阻抗带宽. 仿真结果表明,Ku频段天线水平和垂直极化分别工作在14.4~17.6 GHz和14.4~17.4 GHz,−10 dB阻抗带宽分别为20% 和18.7%;Ka频段天线工作在30~40 GHz,−10 dB阻抗带宽大于28.5%,测试结果与仿真结果吻合良好. 所提出的共口径天线单元具有尺寸小、带宽宽的特点,其横向尺寸为8.5 mm×8.5 mm（0.45λ×0.45λ,λ为Ku频段中心频率16 GHz对应的波长）. 本文为高密度、宽角扫描共口径相控阵天线提供了新颖的天线单元设计方案.     

双圆极化共形相控阵天线研究

设计了一种基于十字缝隙耦合双圆极化微带共形相控阵天线。首先设计了微带天线单元,分析了天线各结构参数对天线性能的影响。通过电桥向偏馈于十字缝隙上的馈线馈电,实现等幅、相差90°馈电,电桥的两个端口分别获得旋向相反的圆极化信号。然后对天线单元进行了测量,结果表明天线轴比小于3dB 的带宽为16%,驻波小于1.5 的带宽 为17%,波束宽度大于87°。最后对5×5 共形相控阵天线进行了仿真与测量,结果显示天线可以扫描60°,适合用作载体共形的卫星通信天线。