一种新颖的超宽带平面等角螺旋天线的设计

分析了平面螺旋天线的研究方法,并设计了工作于2～12 GHz 的新颖的超宽带平面等角螺旋天线,由天线的宽带特性指标和平衡结构特性,天线两臂的辐射部分设计了一种带环状贴片的天线辐射结构,使圆极化轴比带内小于3 dB,天线馈电部分设计了一种阻抗为指数渐变和梯形渐变相结合的双线形式微带线宽带巴伦,并可采用50 W 同轴探针馈电,使带内反射系数小于-10 dB。测试结果表明,馈电的微带巴伦和天线带环状的结构形式都表现出良好的宽频带和圆极化特性。     

圆锥对数螺旋天线的设计和验证

介绍了圆锥对数螺旋天线的特点、原理和设计方法,制作了一种3∶1带宽的圆锥对数螺旋天线,并对实物进行测试验证,测试结果与仿真结果吻合较好。测试结果表明:该天线具有较好的非频变特性,在较小的口径下(直径为1/3最低工作频率波长)实现了良好的前后比,并具有较好的圆极化特性,±60°宽角轴比小于4d B。     

一种S 波段印刷四臂螺旋天线的分析与设计

本文主要分析了一种S 波段的印刷四臂螺旋天线。并设计了一宽波束右旋圆极化介质加载的印刷四臂螺旋天线, 馈电网络采用的是具有两级隔离电阻的威尔金森功分器。该天线的仿真结果与实测结果吻合良好。仿真和实物测试结果表 明,该天线在3.05GHz-3.45GHz 工作频率范围内,具有较好的心形方向图、3dB 波瓣宽度达到160°、全方位角的增益大于 -2dB,轴比小于5dB,驻波比小于1.4。通过机电一体化设计,该四臂螺旋天线具有良好的电气性能,成本低。     

平面螺旋天线及其宽频带巴伦的设计

研究了平面等角螺旋天线设计方法。该天线采用渐变线宽带巴伦馈电,实现了不平衡馈电到平衡馈电的转换, 使得在整个频段内的反射损耗小于-10dB。同时通过在天线一侧设置圆台背腔,实现了天线非频变的单向辐射特性,其 增益达7.5dBi。仿真及测试结果显示,该天线具有良好的驻波比及宽频带辐射特性,满足实际使用要求。     

一种宽带微带八木天线的设计

针对传统八木天线体积过大,难以与其他载体共形,相对带宽很窄的问题,设计了一种宽带微带八木天线。天线采用一种比较简单的馈电方式减小天线的尺寸,利用附加寄生贴片、振子耦合枝节和金属化孔的方式展宽频带和改善天线的阻抗匹配。使用Ansoft公司高频结构仿真器(HFSS)对天线进行仿真设计和优化,并对实物进行测试。最后结果表明,所设计、制作的天线频段在1.81~2.57 GHz内,电压驻波比(VSWR)小于2,相对带宽为31%,在2.4 GHz频率处的增益大于9 dB。仿真和测试结果显示,该宽带微带八木天线基本达到设计要求。     

一种小型化宽带宽波束平面四臂螺旋天线

设计了一种GPS/北斗频段的小型化具有宽带宽波束宽轴比特性的平面四臂螺旋天线。该天线分为馈电网络和辐射体两个部分,馈电网络采用平行双线差分馈电,引入180 o相位差,从而减少了一级功分器,使馈电网络的平面尺寸减小一半;辐射体部分采用平面结构,每个天线臂采用倒F 形式,逆时针旋向印制在介质基板上,中间增加了空气层来增大天线的增益,这种平面结构大大降低了天线的高度。馈电网络的信号通过馈电金属柱传输至辐射体。通过电磁仿真软件Ansoft HFSS 仿真和优化,并制作了实物。测试结果表明:中心频率1. 57 GHz 处的相对带宽(VSWR<1. 5)达到12. 7% ,增益达到3. 38 dBi,俯仰面的半功率波瓣宽度为110 o,俯仰面的3 dB 轴比宽度为132 o,方位面的不圆度为0. 5 dB。     

一种共形宽带圆极化螺旋天线的设计

为满足共形天线低剖面特性的要求,设计并制作了一种低剖面的圆极化阿基米德螺旋天线.天线利用单臂阿基米德螺旋结构实现圆极化辐射,并采用同轴探针馈电.实测结果表明,天线在2～ 11.4 GHlz的频率范围内回波损耗小于-10dB,轴比小于3dB的频率范围为2.5～8.4 GHz.该天线结构简单,工作频带宽,且剖面极低,可作为...     

具备阻抗和低副瓣宽带特性的脊波导缝隙阵列天线设计

设计了一种16×8脊波导缝隙阵列天线,线阵阵面分成两个子阵,馈电采用同轴馈电与耦合缝隙馈电结合的两级馈电方式,辐射缝隙分布为泰勒分布。天线设计采用近场诊断方法和阻抗过载技术进行优化。天线实物加工测试结果表明,天线在X频段驻波带宽(VSWR≤1.5)为7.3%,最低副瓣达到-25.8 dB,副瓣电平带宽(SLL≤-19 dB)为6.2%。与已有文献相比,该天线同时具备阻抗宽带特性和低副瓣宽带特性,工作频带内具有增益均大于16 dBi的高增益特性。     

一种32元宽频带印刷偶极子天线阵列

基于椭圆形印刷偶极子设计了一种宽频带天线阵列,阵列单元与馈电网络均印制在同一介质基板上,易于加工和集成.对影响天线性能的阵列结构参数进行了分析,得到了能够获得较佳电性能的结构参数.对天线进行了仿真分析与实际测试,仿真与测试结果一致性较好.测试结果表明,该阵列在2.32～5.48GHz频率范围内电压驻波比小于2.0,且在该频率范围内具有定向辐射特性,最低增益为17.7dB,最高增益为22dB,相对带宽达到81％.     

超宽带多极化跟踪天线及馈源的设计

随着空间技术的快速发展,对目标飞行器的跟踪与信息截获变得越来越重要。为了实现对目标飞行器的跟踪和信息截获,文中设计了一种超宽带、多极化、高增益的跟踪天线及馈源,采用基于印制板设计的对数周期天线作为单元,并使用八个单元组成圆环阵作为反射面天线的馈源,对结构和馈电幅相进行设计,从而实现线极化比幅跟踪、左旋圆极化接收、右旋圆极化接收三种工作方式。仿真结果表明:单元天线驻波小于2的相对带宽达到147%,次级方向图的圆极化轴比小于4 dB,交叉波束的交叉电平基本稳定在-3 dB~-8 dB。对该跟踪天线进行加工,并进行天线系统测试,实际测试结果与仿真吻合很好。     

一种小型化超宽带MIMO天线设计

提出了一种基于槽天线的小型化、高隔离度的超宽带(Ultra Wideband, UWB)多入多出(Multiple-Input Multiple-Output, MIMO)天线.该MIMO天线由两个槽天线单元构成, 为了增加天线阻抗带宽, 每个槽天线单元由末端带有圆形贴片的微带线和末端为圆形的槽线两部分耦合馈电.采用在地板上开槽和方向图分集方法, 减少地板表面波和空中电磁波影响, 达到提高天线隔离度的目的.数值仿真和实验结果表明:该天线在3.1~11 GHz频段内满足端口反射系数|S₁₁| < -10 dB, 隔离度|S₁₂|在7~11 GHz频段内小于-25 dB, 在3.1~7 GHz频段内小于-16 dB, 并根据仿真和测试S参数计算了包络相关系数.     

新型快速波导缝隙天线设计方法

对馈电网络和天线的散射矩阵进行级联,推导了互耦条件下阵列天线输入端口散射参数和天线实际激励分布的计算方法。基于该方法,提出了一种新型快速波导缝隙天线设计方法,并设计了一副12 元宽边纵缝一维波导缝隙天线。测试结果表明,在9. 82 ~10. 21 GHz 内反射系数和副瓣电平分别优于-15 dB 和-28 dB。测试结果与计算、仿真结果吻合良好,验证了该方法的准确性和有效性。     

Analysis and design of wide band Microstrip-line-fed antenna with defected ground structure for Ku band applications

A wide band Microstrip antenna is proposed for Ku band applications with defected ground structure. A circular shape defect is integrated in the ground plane. A novel equivalent circuit model is proposed for Microstrip patch antenna with defected ground structure. Accurate design equations are presented for the wideband Microstrip antenna and theoretical analysis is done for the proposed structure. The proposed antenna has an impedance bandwidth of 56.67% ranging from 9.8 GHz to 17.55 GHz, which covers Ku-band and partially X-band. The antenna shows good radiation characteristics within the entire band, and has a gain ranging from 5 dBi to 12.08 dBi. Minimum isolation between co-polar and cross-polarization level of 20 dB and 15 dB is achieved in H-plane and E-plane respectively. The simulation of the proposed antenna is done on HFSS v.14, and measured results of fabricated antenna are in good agreement with the theoretical and simulated results.     

新型小尺寸带引向器波纹开眼对拓型Vivaldi天线

基于传统对拓型Vivaldi天线, 提出一种新型小尺寸对拓型Vivaldi天线.采用波纹、开眼和引向器等结构来展宽天线的工作带宽, 并分别对这三种结构对带宽的影响进行了分析.利用HFSS仿真优化得到的结构参数, 分别在两种介质材料上, 加工并测试了带引向器波纹开眼对拓型Vivaldi天线, 实测与仿真结果吻合.仿真与测试结果表明:两种介质上的天线工作频带均包含3~20 GHz, 尺寸仅为42.56 mm×40.16 mm×0.813 mm, 带内回波损耗S₁₁低于-10 dB, 带内增益均大于3 dBi, 最大增益达7.3 dBi, 交叉极化均小于-15 dB, 50%以上的频带交叉极化小于-20 dB, 最小可达-25 dB, 天线具有稳定的方向图, 良好的波形保真度, 是一种宽波束天线.     

一种新型宽带双极化微带贴片天线的设计

摘要：运用口径耦合理论、腔模理论、反相馈电技术和多层贴片结构设计出一种新型的P波段（中心频率为0．75GHz）宽带双极化微带贴片天线。天线的两个极化端口采用共面馈电;馈电网络设计中采用短路耦合线实现反相馈电。仿真结果表明该天线两个极化端口实际增益均达到8．5dB,水平极化端口在0．64-0．85GHz频率范围内驻波比小于2,相对带宽为28％;垂直极化端口在0．68-0．85GHz频率范围内驻波比小于2,相对带宽为22．6％,两端口隔离度高于53dB。     

Conical-reflector antennas

The mechanical advantages of a singly curved conical reflector are demonstrated by the experimental test of a furlable 1.83 m conical-Gregorian antenna at 16.33 GHz. The measured gain of 47.5 dB corresponds to a net efficiency of over 57 percent. A ray-optics analysis of conical-reflector antennas is presented, and data useful in the design of conical antennas is given. The conical-Gregorian antenna, in which a subreflector is used in conjunction with a conventional horn feed, is considered in detail. A physical-optics analysis of the conical-Gregorian antenna is used to investigate diffraction and other effects, and to analytically confirm the high performance of the antenna. It is concluded that conical antennas are a valuable addition to available antenna-design concepts.     

集成鳍线为脊的新型圆锥及方锥TEM喇叭及其在目标瞬态特性中的应用

发明了一种共面波导到鳍线的宽带过渡结,采用该结构方式馈电,研制了一种新型超宽带集成鳍线辐射器,把此种鳍线作为圆锥ＴＥＭ喇叭或者方锥ＴＥＭ喇叭的脊,成为超宽带鳍线加脊的ＴＥＭ喇叭,该种喇叭及其脊的形式均为国内外首创。     

Planar millimeter-wave antennas using SiNx-membranes onGaAs

Planar aperture coupled microstrip antennas for 77 GHz are demonstrated for the first time. As far as possible standard GaAs monolithic microwave/millimeter-wave integrated circuit (MMIC) technology is used to realize the antennas. The antenna patches are suspended on a thin dielectric SiN_x membrane on GaAs substrate. Therefore a novel plasma-enhanced chemical vapor deposition (PECVD) process step for the fabrication of the membranes is developed and described. The single antenna patches are coupled to a microstrip line through an aperture in the ground metallization. The method of moments in spectral domain is applied to design the patches. The feed network of a 3×1 antenna array for homogeneous excitation is simulated and optimized with a microwave design system (MDS). From reflection measurements the operation frequency of this triple patch antenna is determined to be 77.6 GHz. The farfield antenna characteristics are measured in an anechoic chamber, showing good agreement between simulated and measured results and a co- to cross-polarization isolation better than 30 dB     

Coplanar Waveguide Fed Printed Antenna with Compact Size for Broadband Wireless Applications

A novel and simple coplanar waveguide fed compact antenna is introduced in this paper. The antenna structure combines the advantages of CPW with those of the broadband antenna and simplifies the structure of the antenna by reducing the number of metallization level to construct uni-planar antenna. Prototype of the proposed antenna have been constructed and studied experimentally. The measured results agrees well with the simulated prediction and shows a broad bandwidth of 6 GHz ranging from 3.5 GHz to 9.5 GHz with VSWR ≤2 (return loss ≤−10 dB), which is equivalent to 92.3% impedance bandwidth centered at 6.5 GHz. The proposed antenna shows stable radiation characteristics, gain and axial ratio of less than 1 dB over the whole operating bandwidth. Furthermore, an extensive parametric study was performed to realize the relationship between the resonance frequencies of the broadband antennas and different parameters which is helpful for advancement of the antenna design.     

Dual‐polarized MIMO antenna system for WiFi and LTE wireless access point applications

In this paper, a dual‐polarized multiple‐input multiple‐output (MIMO) antenna system suitable for indoor wireless access point is proposed. The presented MIMO antenna system consists of two coplanar‐waveguide‐fed monopole antennas with orthogonally polarized modes. According to the closely spaced structure of the MIMO antenna system, the mutual coupling between the ports is a big challenge. Therefore, a new structure of parasitic element is introduced in order to improve the mutual coupling between the ports. For the purpose of validating the simulated results, the antenna prototype has been fabricated and measured; the comparison of the results shows that there is an acceptable agreement between the measurement and simulation results. The proposed design covers the frequency bands of WiFi (2.4 GHz), Worldwide Interoperability for Microwave Access (2.3 and 2.5 GHz), and Long‐Term Evolution (LTE; 1.5 and 2.6 GHz) applications with a reflection coefficient less than −10 dB and a mutual coupling coefficient better than −15 dB. The MIMO antenna system provides an envelope correlation coefficient less than 0.15, polarization diversity gain more than 9.985 dB, and quasi‐omnidirectional pattern within the expected frequency band. In addition, LTE downlink throughput measurements show that the proposed antenna system delivers data rates close to the theoretical maximum for quadrature phase shift keying, 16 quadrature amplitude modulation (QAM), and 64‐QAM modulations. Copyright © 2014 John Wiley & Sons, Ltd.