大功率短波广播转动天线发射系统

我国首次引进的一套具有世界先进水平的500kW功率等级的带有转动天线的短波广播发射系统即将投入运行。该系统是由一部500kW功率等级的短波广播发射机和一套频率范围为6～26.1MHz的可以360°方向转动的天线组成,其控制系统可以按照播出节目、频率、输出功率、覆盖方向等要求进行系统的控制管理,并且以互为内锁方式实现整个系统的协调控制操作。本文从系统的组成、技术特性、转动天线的驱动和控制、主要部件等几个方面对该系统进行了介绍,希望能对我国有关方面的技术发展起到借鉴作用。     

LTE基站天线阵列设计

天线是移动通信系统的关键硬件设备之一。随着移动通信技术的飞速发展,系统越来越复杂,对天线性能的要求也越来越高。LTE作为第三代通信技术(3G)的长期演进技术,必将在未来的一段时间内对现代通信产生更大的影响,因而对于天线的工作频段、带宽、波束等相关指标也提出了更高的要求。对LTE频段±45°双极化宽带天线单元进行组阵设计和仿真分析,结果表明了该天线阵列工作性能良好。     

基于GA的智能天线系统前端扇区阵列设计

使用遗传算法(Genetic Algorithm)设计了智能天线系统前端的扇区天线阵列。该天线阵列用于TD-SCDMA基站系统中。依据智能天线系统扇区覆盖模式(即广播波束)对方向图的要求，利用GA的全局搜索性能，综合了阵列结构及单元激励相位。对该阵列结构使用GA模拟了智能天线系统工作模式(业务波束)下所要求方向图的阵列激励幅度和相位。给出了实际的智能天线系统前端扇区天线阵列结构，对智能天线技术的应用具有重要意义。     

UG在有源诱偏反辐射导弹天线设计中的应用

针对有源诱偏反辐射导弹天线的技术要求，介绍了如何应用UG软件的强大功能完成一种二维赋形散焦双弯曲反射面天线的设计工作。该天线结构紧凑，具有足够的强度和刚度，满足设计技术要求。     

双频贴片天线研究与设计

无线通信的发展对天线(尤其是贴片天线)的各项性能提出了新的要求。与此同时，双频天线的应用也愈为广泛。总结了贴片天线的主要双频解决方案，包括正交模、多贴片、电抗性加载以及空气缝隙双频贴片等方式，并提出了相应双频贴片天线的适用场合。最后，结合HFSS仿真设计了一个双频双贴片天线，讨论了该天线特性，并对双频天线未来的发展趋势进行了展望。     

新型共孔径导航天线

提出了一种新型共孔径导航天线。利用不同天线具有不同辐射空间的特点，在低频天线弱辐射区加载高频天线辐射区，两天线辐射区域互补的思路实现共孔径。仿真证明天线辐射性能不仅能够满足两种导航要求，同时两个天线端口之间的隔离度大于82 dB。该设计思路对减少机载平台天线的数量，提高系统集成度具有指导意义。     

一种新型天线测试设备的设计

介绍了一种新型天线测试设备－－天线极化转台及升降的设备的设计方法，讨论了关键技术和所采取的技术措施，并给出了它的主要技术指标。该设备的完全满足微波暗室天线测量技术的要求。     

一种小型化短波对数周期天线设计

针对短波天线小型化问题,通过分析燕尾型对数周期天线的工作原理,设计出了一种小型化短波转动对数周期天线.在小尺寸限制下,通过感性加载与L型加载集合的方式,有效地扩展了转动对数周期天线的最低工作频率.该天线可工作在3～30 MHz,而天线长度仅25 m.仿真与实际测试结果表明:该天线电压驻波比小于2.5,增益8 dBi,能够有效地进行2 000 km通信.     

低RCS雷达天线技术的研究和应用

设计和使用具有低ＲＣＳ性能的雷达天线是一项涉及到多项研究领域的课题，一直为国内外所关注。随着对天线散射机理的深入分析，一些创意较新的天线ＲＣＳ减缩技术被提出，如本文介绍的以抑制天线模式项散射为主的选频副反射面和馈源滤波罩等技术，这些技术不但具有较好的低ＲＣＳ性能而且具有较好的适用性，频率选择表面（ＦＳＳ）技术已被广泛地用于卫星多频段通讯，而在低ＲＣＳ雷达天线技术方面同样也具有极其重要的应用价值，ＦＳＳ方面的研究成果有效地改善了使用ＦＳＳ的低ＲＣＳ天线的性能，而低ＲＣＳ天线技术发展的需要又反过来对ＦＳＳ提出了更高的要求，本文对国内外在ＦＳＳ研究方面的成果和发展趋势也作了分析和介绍。     

基于LTCC技术的UHF RFID标签天线设计

RFID标签天线的性能直接影响到整个系统的性能.传统制作方法及偶极子结构使天线在尺寸、增益等重要指标上很难有所突破.依据所涉及的UHF RFID系统的设计参数要求和标签天线高性能、小尺寸的目标,提出了一种基于LTCC技术的新型片式天线结构.它由两层嵌入在LTCC基板中的金属线构成,平面尺寸仅为0.89 cm×1.018 cm.测试结果证明,天线性能达到设计要求.此外,该天线具有全向性好,性能稳定等优点.LTCC技术也为实现UHF RFID标签的全集成化奠定了基础.     

双环天线在3G基站中应用的研究与改进

双环天线在3G基站中的应用是一种新的探索与尝试。本文对双环天线在3G基站中应用的方向图特性、阻抗匹配以及宽频带性能等进行了仿真研究与分析。为了更好地抑制第一副瓣电平,提出了对双环天线进行改进的方案。通过仿真检验,改进后的双环天线能抑制第一副瓣电平约1.4dB。应用改进的双环天线设计了一种基站天线,测试的结果均达到了指标要求,证实了双环天线在3G中的适用性。     

Icosahedrons microstrip antenna network architecture proposal for new USS telecommunication subsystem

The paper presents a new antenna network subsystem architecture developed for application on board wireless communication subsystem. Founded research work results demonstrate the success of mathematical modeling and simulation of the proposed Icosahedrons Microstrip Antenna Network Architecture. Antenna elements are simulated, prototyped and tested. The Icosahedrons Microstrip Antenna Network is developed to meet the visibility requirements during inter small USS satellite radio communications.     

Design of Wide-Band Microstrip Antenna Array at Millimeter Wave Frequencies

This paper describes the Design of Broadside 8-Elements Microstrip Antenna Array at Ka-Band using corporate feed. Array is designed for the Broadband applications for 32 GHz to 36 GHz (4 GHz Bandwidth). The Gain of the Antenna Array is 18 dBi and the 3-dB Beamwidth in E - & H - Plane is 18 degree and 27 degree respectively with minimum sidelobe level of 15 dBc. Antenna test results show a close agreement between the designed and measured values. The Antenna Array has been printed on 10 mil RT-Duriod (ε_r = 2.22) substrate.     

基于天线选择的MIMO—HARQ技术研究

在移动通信技术迅速发展的今天,差错控制技术在保证通信可靠性方面起到越来越重要的作用,因此本文研究了多输入多输出系统中基于天线选择技术的混合自动请求重传技术。发送端的数据经过CRC校验,信道编码、调制,然后经过串／并变换之后发送出去,接收端接收到信息之后经过相反的处理,然后反馈相关的重传信息给发送端,重传时在发射天线集中选择最优的天线组合进行数据重传。本文提出了基于准信道信息的QR分解天线选择算法,研究结果表明,基于QR分解的天线选择算法与穷尽搜索的最优天线选择算法性能相当,但是运算量却少了很多,因此更加适合于运用到现代移动通信系统中。     

用于CDMA中的智能天线技术研究

讨论了应用于CDMA中的智能天线技术,并且利用高阶统计量和累积分布函数的概念,分析了在多径干扰条件下智能天线的性能.     

Minkowski and Hilbert curves based hybrid fractal antenna for wireless applications

In this paper two types of fractal antennas are designed, one by superimposing Hilbert curve on Minkowski curve known as Hilbert Minkowski Antenna (HMA) and other by superimposing Minkowski curve on Hilbert curve known as Minkowski Hilbert Antenna (MHA). Both antennas are compared in terms of performance parameters like gain, S₁₁(dB), radiation pattern, current distribution and VSWR at all resonant frequencies. Both antennas are designed using HFSS software. FR4 material is used as a substrate material. Prototype of both antennas are designed, fabricated and tested at Vector Network Analyzer (VNA). It is found that Hilbert Minkowski Antenna has better performance in terms of Gain while Minkowski Hilbert Antenna is better in terms of number of frequency bands. A comparison between the characteristics of individual Hilbert and Minkowski curve based antennas is done with the characteristics of hybridized (MHA and HMA) antennas. It comes out that MHA and HMA have more number of frequency bands than individual Hilbert and Minkowski curve based antennas. A comparison has also been done between simulated and measured results of both antennas. Simulated and measured results for both the antennas are in agreement with each other.     

第三代移动通信系统TD-SCDMA中的智能天线技术

简要介绍了由我国提交并被国际电联接受的第三代移动通信标准TD-SCDMA系统及其特点。详细阐述了智能天线的概念、自适应算法和波束形成方法。深入分析了智能天线在TD-SCDMA系统中的应用以及使用他的有关问题，最后对智能天线的应用前景进行了展望。     

A Novel Approach towards the Designing of an Antenna for Aircraft Collision Avoidance System

TCAS/ACAS (Traffic/Aircraft Collision Avoidance System) is an airborne system designed to increase cockpit awareness of nearby aircraft and to service as a last defense against mid-air collisions between the aircrafts. In the existing system, four monopole stub elements are used as TCAS directional antenna and one blade type element is used as TCAS Omni-directional antenna. The transmission and reception frequencies of the TCAS antenna are 1.03G Hz and 1.09G Hz respectively. The existing TCAS 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 in identifying the possible threats. In this paper, the focus is on the design and development of a novel Microstrip Antenna Array which can be used for TCAS/ACAS application. Two proposed antenna models are presented here – a Unit Element Dual Feed Microstrip Dual Patch Slotted Antenna and a Compact Microstrip Antenna Array. These are designed in CST tool to meet the current needs of aircraft Collision Avoidance System and to overcome the possible limitations associated with the existing techniques. The performance and other antenna characteristics have been explored from the simulation results followed by the antenna fabrication and measurement. A good Reflection Coefficient and VSWR with proper 50 Ω Impedance Matching, narrow Beamwidth, perfect Directional Radiation Pattern, high Gain and Directivity at the operating frequencies make this proposed antenna a good candidate for TCAS application. The proposed antenna would be expected to meet the requirements of the advanced avionics standards in terms of design simplicity, lightweight and high performance.     

Low profile meander line Printed Quadrifilar Helix Antenna

In this paper, a new approach of meander line technique for Printed Quadrifilar Helix Antenna (PQHA) is studied. Compared with other meander line techniques, this approach has lowered the axial height of antenna greatly and improved the efficiency of model-building in simulation proc-essing. We have focused on the analysis of radiation pattern, axial ratio, and design graph for the Meander line Printed Quadrifilar Helix Antenna (MPQHA). Finally, we have reduced successfully 67% size in geometry compared with traditional PQHA method, and obtained rather reasonable results.     

智能天线及其在TD-SCDMA中的应用

首先从智能天线的基本原理、技术特点出发,阐述了智能天线技术具有很好地解决CDMA移动通信系统中频谱资源与需求的矛盾,提高系统容量等特点。然后重点介绍了在TD-SCDMA中采用智能天线的优点、实现方案及其出现的新问题。最后,提出了智能天线发展的方向。