宽带被动导引头天线系统性能分析

详细讨论了宽带被动导引头中的关键部件－超宽频带天线的性能，并在此基础上分析了三种具备大视角特性的被动测角方法。由于宽带天线没有确定的相位中心，因此不能采用通常的振幅和差式单脉冲法进行宽频带测角。本文提出的波束运算网络可用于一个宽带螺旋天线同时得到两个交叉波束的振幅－振幅式单脉冲系统中。此外，对比幅相干测向法中的测角模糊问题也进行了研究。     

双偏置格里高利天线赋形方法的研究

针对双偏置格里高利天线的赋形技术进行了研究, 给出了一种双偏置格里高利天线的赋形方法.通过全微分条件推导出了副反射面和主反射面的映射关系, 并结合能量守恒定律、反射定律和等光程条件, 求取天线主、副反射面的轮廓曲线.最后给出了一个设计实例, 仿真结果表明:利用文中的赋形方法能够有效控制口面场幅度分布, 实现预期的天线方向图.     

一种重新赋形副反射面的环焦天线设计

首先针对相同口径的环焦天线主反射面通用化需求,对双反射面天线的发展背景和环焦天线优点及赋形机理进行了简要介绍,然后提出了一种在不改变环焦天线的主反射面曲线的基础上,改变馈源照射角和重新赋形环焦天线副反射面曲线的设计方法,最后依据提出的设计方法给出了设计仿真计算,计算结果满足工程需求,避免了天线主反射面重新开模具,实现了环焦天线主反射面通用化,大大降低了天线的生产成本。     

天线正交加权改变天线方向图方法及其应用

指出了目前改变天线方向特性存在的问题和困难;在研究环形天线方向特性的基础上,提出了一种能够快速旋转天线方向图的新方法,即天线正交加权法.该方法可在天线不便旋转或不能旋转的情况下,通过对天线接收的信号进行加权处理控制天线方向图的旋转,达到天线方向图快速改变的目的.最后对该方法的推广应用进行了探讨.该方法具有可靠性高、精确...     

反射面天线与相控阵天线时域响应的比较

天线按照指定的频率和极化方式，以主波束特定的指向辐射平面波，然而脉冲的时域响应将取决于天线结构的设计，本对反射面天线与相控阵天线主瓣主副瓣的时域响应进行比较。     

抗干扰天线及天线阵列研究

本文对抗干扰天线及天线阵列进行了研究,提出了一种小型化的微带贴片天线,并使用该天线单元进行组阵。文中提出的立体天线阵列的主天线单元实现了宽波束和在低仰角方向上增益的改善,能够满足工程应用的需要。     

采用改进的标准场地法测量LPDA

采用改进的标准场地法针对LPDA和复合天线分别进行了测试和比较分析.分析了采用ANSI C63.5:2006测量对数周期天线LPDA和复合天线的自由空间天线系数Fa时,由相位中心引起的误差;对CISPR 16-1-6 (CDV)中的计算公式进行了改进,使得即使配对中的天线结构不相同也可以进行比较准确的测量;然后分别针对LPDA和复合天线进行了试验,并与使用CISPR 16-1-6(CDV)中垂直方法的测量结果进行了比较.结果表明:在200 MHz ～2 GHz范围内大部分频段小于0.6 dB,首末频点差别小于0.9 dB.为了便于工程应用,还提供了背景噪声的抑制措施、电缆的选用原则等.     

自适应性SLC的实际性能

本文论证了自适应天线旁瓣对消器(SLC)的对消性能取决于主、辅天线信号或干扰及有用信号的相干特性,而和统计相关性无直接关系。     

分形天线的特性分析及其在MIMO天线中的应用

分形最基本的特征是自相似特性与分数维,可以很好地应用于设计天线.与传统天线相比,在性能保持相近的情况下,分形天线表现出两个突出的优势:减小天线尺寸和使天线在多频带下工作.文中以Koch天线、分形树天线和分形环天线为例,说明了分形天线减小天线尺寸的优势;以Sierpinski基垫天线为例,说明了分形天线增加天线工作频带的优势.还对Minkowski分形天线阵列进行了分析,表明作为天线阵列单元的分形天线,可以提高天线阵的辐射特性.文中提出了将Minkowski分形天线应用于多输入输出(MIMO)天线中.     

改进型vivaldi天线

常规vivaldi天线存在后向辐射大,主辐射方向增益低的缺点.通过优化常规vivaldi天线贴片形式的方法,改变天线表面的电流分布,得到其改进形式-兔耳形vivaldi天线.对改进型vivaldi天线的电性能进行了分析,设计并制作了一付工作在6～18 GHz的改进型vivaldi天线,与常规vivaldi天线相比,天线增益在整个频带内均有显著的提高.     

标签天线弯曲对射频识别系统性能影响的研究

探讨了工作在微波段的无源射频识别(Radio frequencyIdentification, RFID)系统中标签天线的弧形弯曲对RFID系统性能的影响。分析比较了几种典型的半波振子标签线天线弧形弯曲的情况。通过理论分析确立标签天线的方向系数与输入阻抗为RFID系统性能的主要影响因子。弯曲振子天线特性参数由线天线分析软件NEC WinBasic数值模拟得到。分析结果表明,标签天线的弧形弯曲使得无源RFID系统的工作距离明显变短。因此,为避免此类问题有必要在RFID系统中考虑对于弯曲具有低敏感性的天线结构。     

微带磁流振子天线综述

文章综述了微带磁流振子天线的最新发展情况,从理论上对比了微带磁流振子天线和电流振子天线的辐射机理,阐述了微带磁流振子具有水平极化和高增益的新颖性,最后介绍了微带磁流振子在新型天线阵列、圆极化天线、高增益天线的应用。     

Broadband Active Receiving Patch With Resistive Equalization

The active integrated antenna (AIA) concept has been applied to design a broadband receiver front-end. A design procedure for active broadband patch antennas based on resistive equalization is presented. The use of the AIA has allowed the design of efficient RF front-ends by increasing its effective gain, noise figure, and merit . In addition to improving the classical parameters, the resistive equalization technique allows enlarging the bandwidths of the active antenna parameters versus the corresponding ones in passive antennas. A receiving patch antenna (with one amplifying stage) with a measured noise figure lower than 0.6 dB in a bandwidth over 38% and an effective gain improvement of 13 dB over the corresponding passive antenna has been achieved. The -parameter has also been measured for both the active and passive antenna, resulting in a relative planar of 16 dB/K, with a ripple of 0.5 dB, over a 30% bandwidth for the active antenna versus a of 22 dB/K for a typical front-end with a passive antenna over 20% bandwidth.     

The Performances of the Antennas in Active/Passive Compounded Guidance Part II: Compounded Antennas Schemes and Performances of Active/Passive Guidance

The second part of a two-part paper discusses two kinds common-caliber compound antennas techniques for active/passive guiding system. One is the triple-antenna compound technique which two spiral antennas are utilized to find the direction of a radiative source in passive amplitude-phase monopulse subsystem and the other is used in pulse-radar. The next is the double-antenna technique which one antenna is for passive amplitude-monopulse direction-finding and the another is for pulse-radar. The mutual influence among these antennas is analysed in details and the better one in the scheme is pointed out finally in this paper.     

复权重天线馈电网络的发展现状

近年来,在新兴的通信技术与军事技术的驱动下,多模天线单元与非常规天线阵成为天线技术中的研究热点。这类天线包括各种新型的用到复权重馈电网络的多模天线单元、相位中心连续可移动虚拟天线阵、阵元方向图分集天线阵等等,它们都有重要的应用前景。然而复权重馈电网络的现行解决方案是在馈电网络各支路中级联移相器和可变增益放大器,通过复杂的有源电路甚至有源系统实现。已有方案存在结构复杂、成本高、功耗大等缺点。因此,研究结构简单、低成本、低功耗的无源复权重馈电网络,尤其是可电调无源复权重馈电网络,具有重要的科学意义与广泛的应用价值。文章在这方面提出了若干新的设想。     

移动通信中的天线技术

介绍了移动通信中天线的新技术．阐述了全向高增益天线、多频段天线、极化分集天线和智能天线的实现技术以及在移动通信中的应用。     

岸基远程高频表面波雷达小型宽带天线系统的设计

从高频表面波雷达天线工程的角度出发,基于对数周期天线的设计理论,优化设计了一副小型 宽带发射天线;基于端射阵理论,优化设计了一副小型宽带、具有大前后比的双鞭天线,并以此作为阵列天线的基本单元组成六元均匀线阵。文中分析了收发天线的工作原理,并给出了计算机模拟结果。     

Broadband active microstrip antenna design with the simplified realfrequency technique

This paper deals with the design of broadband active microstrip antennas where the amplifier is integrated with the radiator. Theoretically sound definitions for gain and noise figure of the active antenna are introduced, and their relationships with the definitions for the composing circuit and radiator parts are explained. A sequential design procedure is presented that allows the straightforward and optimal design of transmitting and receiving antennas with multiple active stages, taking into account input and output matching, the gain-versus-frequency curve as well as the noise performance. The theoretical concepts are illustrated with two examples: one of a transmitting active antenna and one of a receiving antenna. The former one is a two-stage design that achieves nearly 25% of bandwidth with regard to gain and matching and 24 dB gain improvement as compared to the matched passive antenna. The second one is a receiving antenna (one stage) with a measured noise figure of 1.2 dB in a bandwidth of over 17% and a gain improvement of 11.9 dB over the corresponding passive antenna. Finally co- and cross-polar radiation patterns in E- and H-plane prove that the antennas also have favorable radiation characteristics in a wide bandwidth (at least 18%)     

新型定向超宽带天线

基于圆片单极天线是一种结构简单的超宽带天线,研究了一种新型的超宽带天线,它将4个圆片单极天线垂直交叉放置作为馈源并采用平板反射面,实现定向以及双极化或圆极化特性。分析了2种变形形式:将平板反射器换为抛物面反射器,实现高增益特性;将圆片振子变形,实现更宽的低频端阻抗带宽。通过电磁仿真软件,计算了天线的S参量和辐射方向图随频率的变化规律。分析表明文中的天线对于传统的圆片单极天线有了有效的改进,实现了超宽带、定向辐射、双极化、圆极化、高增益等不同的特性,它们在卫星通信和移动通信中具有良好的应用前景。     

Active Integrated Antenna Design Using a Contact-Less, Proximity Coupled, Differentially Fed Technique

A novel contact-less, differential feeding technique suitable for integrated active antenna design is demonstrated. This technique utilizes an odd mode signal to generate fringing fields on either side of a microstrip gap under the antenna. This allows electromagnetic energy to be efficiently coupled from the transmission lines to the radiating antenna. In a balanced integrated antenna amplifier configuration, the proposed non-contact feeding method removes the need for any balun or power combining network. Hence in theory, a compact RF front-end design with lower losses can be realized. This feeding method has been successfully applied to the design of simple passive microstrip patch antennas and active integrated antennas (AIA). Simulated and measured results are also included to validate the proposed feeding concept and antenna designs. The performance of the proposed differential feeding technique on a simple microstrip patch antenna has been systematically studied. The study suggests that the proposed proximity method is broadband in nature, allowing antennas operating at different resonant frequencies to be swapped without the need to change the feed dimensions and without degrading the matching performance