一种新型高增益小型化四臂螺旋天线

针对卫星通信、卫星导航设备中四臂螺旋天线低仰角增益低、馈电网络尺寸不能满足安装要求的问题,设计了一种新型四臂螺旋天线,采用折叠式威尔金森(Wilkinson)移相馈电网络馈电,采用类八臂渐变式螺旋臂的方法提升天线低仰角增益。天线仿真和测试结果吻合良好,结果显示,在±60°~±90°低仰角范围内天线增益提高了1~2 dB,天线轴比保持在2以内,馈电网络高度降低了1.5 cm。该四臂螺旋天线具有低仰角高增益、圆极化特性良好、尺寸小等特点。     

陶瓷介质加载四臂螺旋天线

微波陶瓷介质加载的四臂螺旋天线,体积显著减小,而性能基本不变,是应用在小型化卫星导航定位设备中的理想天线。在介绍四臂螺旋天线结构组成、工作原理和发展过程的基础上,讨论了陶瓷介质加载四臂螺旋天线的特性和制作方法,并指出了存在问题和今后的研究方向。     

Ultra-wideband antipodal slot antenna with improved radiation performance

A novel antipodal wide-slot antenna for ultra-wideband (UWB) applications is proposed and studied in detail. The antenna is fed by a microstrip line terminated with a rectangular tuning patch. An antipodal structure is employed to improve the radiation performances. The return losses, surface E-field, current distribution, radiation patterns and gains of the antenna are numerically and experimentally investigated. Results show that the proposed antipodal antenna has an impedance bandwidth from 0.79 to 4.0?GHz, which is about 5:1. Compared with conventional rectangular wide-slot antenna, more stable radiation pattern with lower cross-polarisation level and flatter gain variation over a 3:1 bandwidth can be obtained. Thus, the proposed antenna should be more suitable for future UWB-multiple-input multiple-output applications using polarisation diversity than conventional UWB rectangular slot antennas.     

Circularly polarized patch antenna with simultaneously wide frequency tuning range and high gain performance

A tunable circularly polarized square patch antenna with parasitic elements is designed for a wide frequency tuning range and high gain characteristics. The proposed antenna is constructed by one main patch and four semi-elliptic parasitic units. By loading four varactor diodes and adjusting their capacitance values, the tunable feature is performed to reallocate the corresponding working frequency. Moreover, the diagonal corners of the antenna are cut and loaded with varactor diodes, which provide the appropriate perturbation between the two orthogonality modes of the antenna, so as to ensure the circular polarization characteristic in the entire operating tuning band. The experimental results demonstrate that the reflection coefficient and axial ratio are less than −13 dB and 3 dB, respectively. The proposed antenna features a relatively wide continuously tuning range of 24% within 1.9-2.3 GHz and a stable gain of over 7 dBi with a radiation efficiency of above 85%.     

基于卫星移动MIMO系统的天线相关性性能分析

研究了卫星移动MIMO系统中,上、下行信道存在阴影衰落和空间相关条件下的系统性能,利用围线积分、留数定理及特殊函数积分等方法推导了系统中断概率(OP),平均符号错误概率(SER)的闭合表达式。利用Monte-Carlo仿真分析了系统在不同相关系数、天线数目及调制方式下的性能表现。仿真结果表明,尽管阴影衰落和空间相关性降低了系统性能,但与单天线系统相比,卫星移动MIMO系统的OP及SER改善明显。     

单一卫星天线安装双馈源的研究

为解决双馈源卫星地面上天线的安装调试问题，根据几何光学原理，阐述并推导出确定焦点的基本公式和工程实用化公式，提出了选取最佳接收截获面的论点。     

Dual band monopole antenna based on metamaterial structure with narrowband and UWB resonances with reconfigurable quality

In this article, an Ultra Wide Band (UWB) monopole antenna based on Metamaterial (MTM) unit cell with reconfigurable feature has been developed. The proposed antenna covers 3.1–10.6 GHz for UWB applications and it has a reconfigurable narrow-band for L-band (1.27 GHz) and wireless applications. The gaps in Split Rings Resonator (SRR) element are made for the Left-hand capacitance and Ω-shape strip layer by four via junctions are used for Left-hand inductance. The antenna is printed on FR-4 low cost substrate with relative permittivity of 4.4 and thickness of 1.6 mm. The total size of the antenna is 40 mm × 40 mm. The simulation is carried out using HFSS commercial full-wave software. In addition, the experimental results are presented and compared with simulated results. The antenna gives a maximum peak gain of 6 dBi with Omni-Directional radiation pattern and high efficiency of more than 70%. By embedding four switches in Ω-shape strip layer, a reconfigurable antenna has been successfully designed for wireless applications with sufficient qualification. The monopole part covers the UWB spectrum and the CRLH is responsible for the controllable narrowband resonance. The simulation and experimental results are confirmed by the numerical results.     

一种远程动中通卫星天线的设计与实现

卫星移动通信系统具有覆盖区域大、通信距离远、通信机动灵活等优点。卫星移动通信为远程动中通技术的发展、实现全球的无缝连接提供了契机。介绍了一种高性能、低轮廓Ku频段远程动中通卫星天线的工作原理,提出了动中通天线空间维和功能维概念,应用了喇叭天线阵波导馈电技术,给出了动中通天线设计与集成方法,分析了动中通天线可靠跟踪的关键技术并进行了设计实现。测试结果表明天线性能优良。     

基于阵列天线的多用户联合检测算法和性能研究

本文研究了将智能天线与多用户联合检测结合使用的原理、方法和实现过程。文中详细讨论了多用户的CDMA系统在阵列天线接收时的信号模型和实现联合检测的算法模型，重点分析和论证了在使用智能天线的情况下，将该模型进行优化和简化的可行性，研究了将两者结合使用后系统所具有的性能和存在的问题，最后给出了对主要性能的仿真结果。     

非整数倍采样情况下的定时恢复研究

针对宽带卫星通信系统中非整数倍采样的定时恢复问题,介绍了一种整数倍变换法—将非整数倍采样信号进行速率整数倍变换后再进行定时估计,并提出了一种新的定时恢复方法。这种新方法对采样数据直接进行定时估计,然后再内插出同步信号。通过对两种方法的分析比较可知,新方法的实现复杂度更低,定时恢复性能更好。     

基于FAD天线的TD-LTE与TD-SCDMA协同优化方法研究

2013年中国移动面临着全网20万站点的建设规模,TD-LTE网络规划和网络优化面临很大压力。本文针对TD-LTE与TD-SCDMA共FAD智能天线场景提出了智能天线广播波束成形方法,采用独立的广播波束成形参数,降低两系统的RF耦合度,最终做到两系统独立优化,最后给出两系统协同优化方法与流程。     

船载卫通站天线控制单元引导计算异常的解决

某船载卫通站天线控制单元( ACU)在一次任务海域使用捷联惯导( SINS)作为数据源引导计算时出现了卫星捕获异常情况。针对该问题,从分析船载卫通站卫星捕获原理入手,详细比对了各类引导源的数据格式与异同点,结合以往工程经验进行问题排查定位,提出了相应的解决方案并完成了ACU软件的修改完善和测试验证。试验结果表明,采用所提方法,问题定位准确,解决方案简单有效、可行性强,可为类似问题的解决提供参考。     

相控阵结合伺服辅助的车载动中通天线跟踪方法

天线跟踪功能是车载动中通系统( SOTM)提供无线通信能力的前提,相控阵天线能提供较好的跟踪性能,但是存在波束扫描范围有限的问题。为实现相控阵天线全方位跟踪能力,提出了一种相控阵+伺服辅助的方法。给出了算法数据处理流程,并完成了原理样机设计。根据原理样机工作原理给出了跟踪角误差计算公式,测试结果与计算结果相符。测试结果表明：在(57.88~115.76)。/s角速度下,通信链路信噪比损失小于0.5 dB。     

ADC量化位数对阵列天线GNSS接收机的影响

在处理全球卫星导航系统（Global Navigation Satellite System,GNSS）卫星信号时,针对模数转换器（Analog-to-Digital Converter,ADC）量化位数不同导致输出的信号信噪比下降的问题,推导了阵列天线波束形成后输出信号的信噪比理论计算模型,分析了ADC量化位数对阵列天线抗干扰GNSS接收机的性能影响。在7阵元天线且ADC量化位数为10的条件下,理论模型分析和数据仿真结果表明最大抗干扰能力约为85 dB。通过确定ADC量化位数与抗干扰GNSS接收机抗干扰能力之间的关系,其结论为工程应用中抗干扰GNSS接收机的ADC选型和设计提供了理论依据。     

前馈偏置卡塞格伦天线低轮廓设计

低轮廓卫星通信天线不仅具有很好的应用前景,而且具有重要的理论研究价值。前馈偏置卡塞格伦天线不仅具有较高的效率,而且可实现Ku频段和Ka频段双频段共用。给出了前馈偏置卡塞格伦天线实现低轮廓设计的3个步骤:合理配置各参数,使天线高度达到可以满足要求的值;进行椭圆口面赋形设计,达到天线电气所需要的等效口径面积;选择主面的旋转轴,保证主面转轴后电气性能和天线高度变化不大。     

TD-LTE网络中小型化天线的应用研究

本文应用无线网络规划仿真的方法,对小型化天线在TD-LTE网络中应用的性能进行了评估。根据目前小型化天线指标恶化程度的现状,在理想蜂窝结构以及实际现网工程中,通过仿真对比,给出了小型化天线在实际TD-LTE网络中的应用建议。     

倒装焊结构对太赫兹对数周期天线的影响

设计了一种倒装焊结构,用于340GHz的肖特基二极管探测器。探测单元是基于砷化镓（GaAs）工艺设计的。薄膜陶瓷支撑层旨在为太赫兹检测单元提供封装。通常,导电胶用作天线和输出电路之间的附接。分别对倒装焊结构和无倒装焊结构（类引线键合结构）模型对太赫兹接收天线性能的影响进行研究。为了比较的目的,使用相同的测试系统表征FC结构模型和无FC结构模型（引线键合结构）。通过引线键合与倒装焊测试增益的结果比较,表明倒装焊结构可以作为大规模太赫兹检测阵列封装的低成本解决方案。     

基于左手材料提高微带天线方向性的研究

左手材料是介电常数和磁导率全为负值的新型人工合成电磁材料,在其中传播电磁波的群速度与相速度方向相反。利用左手材料的平板透镜聚焦特性,可以改善天线的辐射性能,提高天线的方向性。在此利用左手材料这一特性设计出基于左手材料的微带天线。研究结果显示,加载左手材料以后的微带天线半功率束宽减小29°。验证了左手材料能够提高天线方向性这一特性。     

Design and investigations on a compact,UWB, monopole antenna with reconfigurable band notches for 5.2/5.8 GHz WLAN and 5.5 GHz Wi‐MAX bands

This article represents a microstrip line–fed novel circular monopole antenna with ultra‐wideband (UWB) characteristics. The compact antenna provides reconfigurable notches at WLAN (5.2/5.8 GHz) and Wi‐MAX (5.5 GHz) frequency bands. The band rejection is achieved by etching an open‐ended L‐shaped slot in the ground plane, which effectively mitigates the interference between WLAN, Wi‐MAX, and UWB systems with an effective patch area of 36.26%. The proposed antenna operates from 3.05 to 12.11 GHz with VSWR 2 except at stopband (3.89‐5.93 GHz) to filter the WLAN and Wi‐MAX signals. The simulated return loss, gain, and radiation pattern of the proposed antenna has been experimentally verified with the fabricated one which holds a good agreement.