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美国、澳大利亚 美、澳联合开发新型GPS天线,有望提高市区导航精度 据GPS WORLD网站报道,美国空军工程学院和澳大利亚堪培拉的Locata公司联合开发出了一款新型GPS天线,名为“VRay”。这种“球状”天线,采用“波束赋形”技术,能够有效地降低多径干扰等影响因素,从而改善导航系统在城区、室内等环境的定位精度。而与传统的赋形天线相比,这种天线克服了需要多套接收链路单元的缺点,只利用一套接收单元在几十个天线元之间高速切换,从而有效地降低了天线尺寸和成本。     

基于GPS一机多天线的大坝形变监测系统

GPS多天线系统是将微波技术，计算机实时控制技术，大地测量数据处理和定位算法有机的结合起来，仅用一部GPS接收机互不干扰的接收到8个GPS天线传输来的信号，并通过后处理软件包实现2-3mm定位精度，本文介绍了作者开发的GPS一机多天线控制系统在大坝形变监测中的应用。     

功率倒置算法在GPS接收机天线抗干扰中的应用

GPS接收机天线易受其它射频信号干扰,传统的做法已不能满足高精度用户的需求.为了提高导航定位精度,在GPS天线抗干扰设计中引入了功率倒置算法.功率倒置算法具备在不明确干扰信号相关背景的情况下能够有效抑制干扰,据此设计了采用功率倒置算法的GPS天线接收模型,并对半物理实物进行了相关仿真,取得了较好测量精度.     

四线螺旋结构GPS接收天线的设计

介绍一种基于微带馈电方式的四线螺旋结构GPS接收天线。该天线自带移相器和匹配网络，结构紧凑可靠。实验结果表明，该天线具有良好的阻抗匹配和辐射特性，天线参数符合实用GPS天线的需要，是一种实用GPS接收天线。     

车载定向天线云台随动系统设计

在无线图像传输通信系统中,要获得较高的接收增益,需要定向接收天线对准信号发射源。本文针对由指挥车和被控车辆组成的应用平台,利用磁罗盘和GPS的定向、定位技术设计了车载定向天线云台随动系统。在该系统中,定向接收天线和磁罗盘固定在指挥车云台上,GPS接收机天线安装在指挥车上。通过随动系统控制云台转动,     

一种有限空间内中短波宽带接收天线设计

一种适用于全球数字广播DRM系统移动终端的中短波宽带接收天线,能够集成于接收机机壳表面,在机壳表面的三维方向上分别设计有Hilbert分形天线、弯折线天线、多环环形天线,将三种天线在馈电端相连,向射频前端电路馈电.Hilbert分形由于其自相似性和空间填充性,应用于天线设计能够实现多频带、低谐振频率等特性.通过计算和大量实验,研究了这种天线的尺寸缩减特性和灵敏度特性.测试结果表明:与专业公司提供的两款DRM接收机天线相比较,该中短波宽带接收天线在1～20 MHZ频率范围内,以缩小的尺寸获得了高的接收灵敏度.     

导航卫星跟踪体制及精度分析

采用卫星仿真工具包对全球卫星导航系统包括GPS、Galileo、Compass等导航卫星星座的地面站天线方位、俯仰跟踪特性进行了仿真分析,以大口径地面接收天线为例讨论了可行的地面站天线座架形式和跟踪体制.并综合常规卫星通信抛物面天线精度分析方法和测控雷达天线的精度分析方法对跟踪精度进行了系统的分析,分析结果可作为今后类...     

MMDS天线技术及其应用

近年来，由于我国有线电视的迅速发展，ＭＭＤＳ多路微波分配系统的传输与分配技术得到了广泛的应用。ＭＭＤＳ天线是ＭＭＤＳ系统的重要组成部分。为满足全方位、大范围内的区域覆盖或特定异形扇区覆盖或多点定向传输的需要，形成了各种全向和定向ＭＭＤＳ发射天线及接收天线。笔者通过对现有微波天线技术和工艺的分析发现，ＭＭＤＳ发射天线一般采用波导缝隙阵列式天线、圆柱形同轴振子阵列式天线、喇叭天线、抛物盒式天线等形式；ＭＭＤＳ接收天线多采用矩形栅状抛物面天线及圆形网状抛物面天线。这几种天线都具有电气性能好、结构简单、…     

一种基于多阵元天线的GPS抗欺骗干扰方法

首先在研究GPS欺骗干扰特性的基础上,寻找转发欺骗干扰和自主生成式欺骗干扰的共同特点;其次,利用多阵元接收天线的DBF技术和RAIM算法,提出一种针对GPS欺骗干扰的抗干扰方法;最后,通过试验验证该方法的可行性.试验证明该抗GPS欺骗干扰的方法针对性强,对抗欺骗干扰效果较好,可应用于民用和军用GPS接收机抗干扰当中.     

新型多星卫星接收天线

本文综述了基于菲涅尔原理聚焦的新型多星卫星接收天线,包括菲涅尔区相位修正结构的聚焦特点,多星卫星接收天线的实现形式、各自的特点及研究状况等。实践证明:接收多颗卫星信号技术的应用,必将取得较好的经济效益和社会效益。     

Optimization of PIFA-IFA combination in handset antenna designs

As commercial needs have expanded the functions of the wireless cellular handsets, multiantenna development in one handset has become more and more common. This paper addresses a multiantenna solution for the wireless handset application. A planar inverted "F" antenna (PIFA) was designed as the main antenna of the handset to cover the 800 MHz band (824 MHz-894 MHz) and the 1900 MHz band (1850 MHz-1990 MHz). A side-mounted inverted "F" antenna (IFA) was designed as the 1575.42 MHz global positioning system (GPS) antenna. The location of the feed/ground pins of both antennas affected not only the total antenna efficiency, but also the polarization of the GPS IFA. The length of the GPS IFA affected the isolation between the two antennas and the specific absorption rate (SAR) of the PIFA at the 1900 MHz band. A three-dimensional efficiency measurement of the prototypes in both free space and against-head position will be presented. Measurement of SAR and its distribution will also be presented to demonstrate the impact of the IFA on the near field of the PIFA.     

Environment effects and system performance characterisation of GPS antennas for mobile terminals

The GPS antenna on mobile terminals suffers from multipath effects owing to reflection, diffraction and scattering of the incident wave in a radio environment. A traditional approach to evaluate the GPS antenna performance in a real multipath environment is therefore insufficient. Presented is a new technique to characterise these environmental effects and the system performance of GPS antennas on mobile terminals.     

卫星移动通信地球站天线发展综述

自20世纪90年代以来,卫星移动通信的迅猛发展推动了天线技术的进步.本文在介绍卫星移动通信地球站天线的分类和系统要求的基础上,着重阐述了几种定向天线的具体形式及技术特点,最后根据作者在该领域多年的研究经验指出了未来移动地球站天线的发展方向和有待研究的关键技术.     

Comparative study of high-performance GPS receiving antenna designs

The FAA decision allowing the use of the global positioning system (GPS) as a radio navigation and landing help system in the United States commercial airports boosts the need for a high-performance GPS receiver which provides the demanded precision. The design of the receiving antenna is one of the most important parts in the design process, as it has to face significant challenges including uniform coverage of all satellites and the rejection of the multipath signals. The rejection of the multipath signals is accomplished by specifying restrictive criteria to the GPS antenna. This includes a high rejection of the cross-polarized signals and a radiation pattern with a sharp slope for low-elevation angles; that is, near the horizon. The feasibility of using different types of antennas to satisfy restrictive criteria such as dual-frequency coverage (L1 and L2 frequencies), -15 dB cross-polarization rejection, and a beamwidth of more than 130° is discussed. The antenna designs examined in this study include patch antennas, helical antennas, and conical spiral antennas. Two different receiver designs were also examined including a single-antenna system with a hemispherical coverage and an antenna array which may provide independent sectoral coverage or the desired beamwidth. It is shown that a design based on a conical spiral antenna backed with absorbing material may be used to satisfy all the desired specifications. This result was confirmed experimentally     

Slot stripline circular-polarization antennas for a few-element antenna array for a high-accuracy receiver of signals from global navigation satellite systems

New radiators for slot stripline leaky-wave circular-polarization antennas for high-accuracy GLONASS/GPS receivers have been developed. The main technical characteristics of antennas with new radiators have been theoretically and experimentally studied. It is shown that application of the new radiators improves the axial ratio, increases suppression of the cross polarization, increases the stability of the antenna phase center, and thus can increase the GLONASS/GPS positioning accuracy. The results of the analysis of the GLONASS/GPS positioning accuracy with the use of these antennas in an angle-measuring receiver and as elements of a few-element antenna array are presented.     

Novel integrated GPS/RKES/PCS antenna for vehicular application

This letter presents the design of a novel integrated global positioning system (GPS)/remote keyless entry system (RKES)/personal communication system (PCS) antenna for vehicular application. The GPS (1575.42 /spl plusmn/ 1.023MHz) antenna element is a corner truncated microstrip patch providing circularly polarized broadside radiation pattern. The normal mode helical and monopole antennas are combined into one for RKES/PCS (447.7375MHz/1750-1870MHz) services. The proposed antenna satisfies all the bandwidth and gain requirements for GPS and RKES/PCS services. Good radiation characteristics for vehicular application have also been obtained.     

基于DSP的GPS双天线实时姿态测量系统实现

实现了基于DSP的GPS双天线实时姿态测量系统，采用Kalman滤波估计载体的位置，速度和初始模糊值搜索距离，然后采用FASF和LAMBDA解算整周模糊度和直接法计算载体的姿态。给出了基于DSP的硬件实现，相对于传统的模糊度解算方法，所采用的整周模糊度解算方法具有效率更高，更便于实时和动态应用的特点，实现了与多天线GPS姿态测量系统相当的精度。对GPS姿态测量技术的工程应用和理论研究具有一定的参考价值。     

一种双频GPS天线设计

使用差分双频GPS定位技术可以实现厘米级定位精度,在此技术中GPS天线的相位中心稳定性是实现高精度定位的一个关键环节.利用仿真软件分析设计了一种缝隙耦合微带天线(ACMA),制作了试验天线,天线的测试结果表明,天线相位中心稳定性良好,可以满足差分双频GPS定位系统要求。     

Multipath-rejecting GPS antennas

Multipath interference limits the speed and accuracy of determining position by differential Global Positioning System (DGPS) techniques. A geodetic surveyor for example, requires multipath interference rejection of about 36+20log₁₀sinϵ dB, where ϵ is the elevation angle of the satellite being observed. Signal processing in a GPS receiver cannot satisfy this requirement. A receiving antenna is required that can sufficiently reject signals arriving from below the horizon. Available antennas have inadequate rejection, and brute-force methods of improving them, e.g., by enlarging their ground-planes, are impractical. A compact, ground-planeless, dual-band GPS antenna with improved multipath rejection has been designed and field-tested. This antenna resembles a vertical post rather than a horizontal platter; within its 0.1-m diameter, 0.4-m tall randome is a vertical array of turnstile elements. In field tests, a three-element array antenna rejected multipath better than a 0.5-m diameter ground-plane antenna by an average of 5 dB. A five-element array antenna appears superior to a 0.9-m diameter ground-plane antenna     

箭载共形相控阵天线波控系统设计分析

为完成适用于天基测控的箭载共形相控阵天线对波束指向控制的需求,分析了箭载天线波控系统的设计要求与任务,论述了平面相控阵天线波控系统的实现方法,并根据波控系统基本原理推导出基于阵因子函数的箭载共形相控阵天线波控算法。针对运载火箭天基测控这一新需求提出了基于查表法的集中式波控设计方案,给出了系统设计方法。样机测试结果表明,该波控系统方案正确、可行,满足工程需求。