电波传播与天线

Z99-51318-95 0012899角形反射器天线辐射方向图的优化[会]/张强//全国电磁兼容学术会议论文集.—95～98(C)本文用网络模型法分析了角形反射器天线的辐射特性。在分析中,结合脉冲点配法,采用了有效的节点约束方程。在分析的基础上,以角形反射器几何尺寸为参数,对天线方向图进行了优化,其计算结果与实测结果一致性良好。参9Z99-51326-139 0012900军事电子设备用毫米波和亚毫米波传输线[会]/赵芳灿//微波学会第三届全国毫米波亚毫米波学术会议论文集.—139～142(C)     

波纹角形反射器系统

一种新型的波纹反射单元的角形反射器(CR)系统已经制成,并提供了试验结果。该系统的性能优于平面单元的一般角形反射器。本文与相对应的平面角形反射器系统直接比较,给出了波纹角形反射器系统的半功率波束宽度(HPBW)、轴向功率、电压驻波比(VSWR)等试验数据。     

压缩天线测试场的特性

本文提出压缩天线测试场的原理,考虑了影响性能的主要因素,包括反射器边缘绕射,反射器表面精度,馈源辐射方向图和反射器焦距。已用一个三米直径的抛物面反射器研究了压缩天线测试场的实际性能,反射器边缘的绕射已用锯齿形边缘加以控制。这个压缩测试场已成功地用于测量频率为3GHz到40GHz、直径达1.2米的天线。     

无源反射器天线大观

这种天线成本低兼、制作方便,能改善VHF/UHF无线电接收机的性能。 一、反射器平面天线(Reflector Plane Antenna) 反射器天线就是一种偶极子(dipole)天线或多(multiple)偶极子天线,不过在其背后相距四分之一波长处还有一反射器平面(reflector Plane),具体见图1。这样的装置就将双向偶极子天线转换成无方向天线。由于反射特性的改变,反射器平面天线的增益比偶极子天     

适合于空间不同用途的大型可展开天线

本文描述了一种可在太空应用的12m大型可展开反射器天线的设计、研制和实现计划，这项工作正在进行中。反射器天线系统是欧洲航天局（ESA）交付给主承包商AleniaSpazio公司的一项合同中的主要内容。作为子承包商，俄罗斯NPOEGS公司负责其中的一个重要单元，即可展开反射器。Alenia公司和欧洲航天局共同提供对反射器无源交调（PIM）性能进行评估的试验设备和鉴定报告，目前，正在为反射器的环境试验做准备。在与一台曾经在MIR空间站上运行的天线进行比较后，已将来自格利高里天线设计的基本经验融合到该方案中。     

提高简单波段天线效率的方法

在本文中指出,广泛採用的对称波段振子的效率,可以由採用与振子平行的导线纲构成的平面反射器而得到显著的提高,导线与振子平行並与振子悬挂在公共的天线杆上。将由二波段振子並带有格子形的反射器所组成的天线与菱形天线比较表明,在波段内带反射器的波段振子的技术经济指标比菱形天线较好。     

大型航天器天线的热控制

为了满足航天飞行器射频性能的要求，必须使用大型、精密天线反射器。稳定性的要求也是以反射器的性能为基础的。反射器设计要求结构性能、热性能及电气性能设计具有智能化组合功能。设计必须将作用在射频信号上的任何热控制部件的不利影响减到最小。本文阐述结构的影响及作用在反射器热设计上的射频条件，并比较几种可能的热设计方案及具体设计分析。     

具有梯形有源振子的印刷引向天线研究

设计了一种采用平衡微带线馈电的具有梯形有源振子的印刷引向天线。对梯形印刷有源振子的阻抗特性进行了仿真,在此基础上进行了改进,首先是有源振子加载反射器,然后是有源振子加载引向器和反射器。仿真了天线的阻抗特性和辐射特性,并分别制作了天线实物进行测试。仿真与实验结果表明,有源振子加载引向器和反射器后的工作频带为2.0~2.45GHz,相对带宽达20.2%,带内增益为6dB 左右,且具有较小的尺寸（60 mm×65 mm）,可用于移动通信领域。     

用胶木板制作的卫星接收天线反射器

电视卫星接收天线用抛物形反射器完成反射聚焦电信号的功能,是大家比较熟悉的,但不是唯一能够完成上述功能的反射器。目前,世界上第一个依据菲涅耳透镜原理用胶木板制成的卫星接收天线反射器已由加拿大科学部罗伯特试制成功。这种反射器不仅成本极低且性能优良,某些方面使得传统的抛物形反射器望尘莫及,下面介绍它的原理及设计制作方法。一、菲涅耳透镜的理论要点 1815年法国物理学家菲涅耳首先发明了以他名字命名的菲涅耳透镜。通常菲涅耳透镜被     

喇叭反射器天线的电气性能

1.引言喇叭抛物面反射器天线分角锥形和圆锥形两种,这类天线的特点是频带宽、噪声低和便于操作,因此,卫星通讯地面站采用了这类天线。角锥形喇叭抛物面反射器天线是     

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。     

等离子体天线的基本特性仿真

等离子体天线具有隐身、动态重构等不同于金属天线的独特的物理性质,在卫星遥感、通信、导航领域具有潜在的应用前景。为了研究等离子体频率对天线特性的影响,采用三维电磁仿真软件建立了柱形等离子体天线模型,在此基础上,针对等离子体频率对等离子体天线的S11曲线、方向图、增益等性能的影响进行了仿真分析,并给出了相关结论。     

紧凑型共面波导馈电的超宽带印刷天线设计

针对超宽带天线设计的重要性,基于微带天线和电磁散射理论,设计和分析了一种新的紧凑型共面波导反馈超宽带印刷天线。天线采用逆L型和U型非对称的辐射单元结构,以便最大程度地展宽天线带宽。与以往所提出的共面波导馈电天线相比,该天线具有尺寸小、近线性阻抗、高增益、宽频带、准全向性辐射模式和低成本等特点。并且,该天线的主要性能参数达到了一个较好的平衡。仿真和测量结果保持一致。该天线能满足多种宽带无线通信应用的要求。     

Brewster angle effect on the performance of omni-directional circular dielectric grating antenna-improved perturbation analysis

The radiation characteristics of the omni-directional periodic leaky wave antenna operating in TMol mode is investigated by the improved perturbation method with a particular attention directed to the Brewster angle effect on the performance of the antenna, and some interesting results are given.     

一种新的平面椭圆单极子超宽带天线

研究了超宽带天线的设计,提出了一种适合天线特征的设计方法。该文所提出的天线设计,讨论的是超宽带天线的综合特征,主要是基于频域的传递函数对各个参数的测量,即波形相关性、波形宽带拉伸比、波形相对增益。仿真结果表明,天线的整体性能和特征表现均很好,特别是在天线孔径方面有更好的表现。通过对这些参数的测量可定量地描述超宽带的传输性能。     

Self-phasing antenna array techniques for mobile communicationsapplications

This paper provides a summary of the basic concepts of retrodirective antenna arrays. Originally this class of antenna was developed in the 1960s for direct satellite-to-ground transmission of high-power microwave energy. The explosive growth of mobile communications has, in the authors' opinion, reopened the debate for alternative applications of retrodirective array techniques. Advances in microstrip antenna design coupled with the availability of integrated circuit amplifier and mixer components permit minimum-complexity retrodirective antenna arrays to be constructed. Several different planar retrodirective antenna architectures are presented and their basic operational characteristics given. A novel application for co-operating retrodirective antennas in a duplex communication link with inherent space division multiple access capability is also described. Finally some of the operational parameters which could ultimately limit the performance of this class of antenna are discussed     

移动通信天线远场三维测试系统集成技术

针对现有及未来5G移动通信天线空间辐射特性测试需求和特点,设计了一套分布式天线远场三维测试系统,集成于高性能微波暗室内。发射天线采用多工位设计,高效率地实现了远程无人值守测试。基于U型测试转台实现了待测天线的三维方向图一键测试,具备双测试通路多频点多端口测试功能,有效提高了天线测试效率。系统软件具有较强后处理能力,将测试理论知识有效地应用于工程实践,如软件时域门和远场修正技术等,可获取更为精确的测试结果。以运营商提供的定向基站天线作为系统性能验证鉴定天线,通过与其在其它优良测试远场获取的测试数据进行对比。结果表明,本系统能够较好地满足运营商对目前移动通信天线测试场地及设备的测试要求,具备一键测试、多功能、宽频带、高精度、高效率等特点,易于拓展具备5G移动通信天线空间辐射特性的测试功能。     

Design and development of a unit element microstrip antenna for aircraft collision avoidance system

Aircraft/traffic alert and collision avoidance system (ACAS/TCAS) is an airborne system which is designed to provide the service as a last defense equipment for avoiding mid-air collisions between the aircraft. In the existing system, four monopole stub-elements are used as ACAS directional antenna and one blade type element is used as ACAS omnidirectional antenna. The existing ACAS antenna has some drawbacks such as low gain, large beamwidth, frequency and beam tuning/scanning issues etc. Antenna issues like unwanted signals reception may create difficulties to identify the possible threats. In this paper, the focus is on the design and development of a unit element microstrip antenna which can be used for ACAS application and to overcome the possible limitations associated with the existing techniques. Two proposed antenna models are presented here, which are single feed and dual feed microstrip dual patch slotted antenna. These are designed and simulated in CST Microwave Studio tool. The performance and other antenna characteristics have been explored from the simulation results followed by the antenna fabrication and measurement. A good reflection coefficient, Voltage Standing Wave Ratio (VSWR), narrow beamwidth, perfect directional radiation pattern, high gain and directivity make this proposed antenna a good candidate for this application.     

Phased array antennas for mobile communications

An antenna system including antenna elements and a tracking method is considered a key technology in mobile communication systems. A phased array antenna has been considered the most favorite candidate because of many attractive characteristics such as a low and compact profile, high-speed tracking and potentially low cost performance for vehicle antennas in mobile communications. On the other hand, it has several such disadvantages as beam steering error, loss in feed lines and an increase of noise level in a receiving frequency band. Some of phased array antennas have already been used in satellite communications, and some of them are under development. This paper overviewed basic performance and some examples of phased array antennas for especially satellite mobile communications.     

TV Antenna Performance Evaluation with RF Pulse Techniques

One of the most critical performance characteristics of a TV antenna system is its ability to transmit a ghost-free picture. RF pulse techniques have been developed to evaluate this performance characteristic. Such measurements can be made to simulate the actual operational conditions of the antenna system very closely. During the past years, several RF pulse-measuring methods have gained acceptance here and abroad. The principles of some of these techniques are presented here and their advantages and limitations are evaluated. Additionally, some instrumentation problems are presented and precautionary steps indicated.