共查询到19条相似文献,搜索用时 109 毫秒
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总结了在卫星通信中椭圆波束天线的应用场合,分析了各种椭圆波束天线的性能及其优缺点,给出了如何提高椭圆波束天线效率及极化性能的方法,并探讨了这类天线在卫星通信中的发展趋势。 相似文献
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本文概述九十年代通信技术的新动向,主要讲卫星通信、移动通信、光纤通信以及公用和专用通信网传输技术的发展趋势。文中着重指出各种有前途的新技术,包括卫星通信的星上点波束天线,小孔径天线地面终端,与ISDN兼容;数字移动通信的蜂窝微区(micro-cell),个人便携通信的无线接入交换网;光纤通信的掺铒光纤放大器,DFB调谐单频激光管,多量子阱(MQW),光电子集成,外差检测,密集FDM多路载波通信;以及公用通信网数字化、综合化、宽带化组成B-ISDN,同步光纤网,同步数字体系,异步转移方式;专用通信网的局域网(LAN和MAN),光纤分布数据接口,分隙环(slotted ring),分布排队双总线等新建议。 相似文献
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本文简要介绍了星座通信星载多波束天线的应用现状和发展趋势,分析比较了几种典型多波束天线的性能特点,提出了数字波束形成(DBF)技术应用于星座通信系统星载多波束天线的可行性方案,针对星座通信系统特点,对数字多波束天线的关键技术问题进行了初步探讨. 相似文献
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Shingo Ohmori 《电信纪事》1999,54(1-2):93-102
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. 相似文献
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Zixuan Ren Jin Jin Wei Li Yafeng Zhan 《International Journal of Satellite Communications and Networking》2023,41(4):374-391
The current satellite communications (SatComs) systems are composed of a large number of satellites, beams and terrestrial devices. Due to their multinode dynamic nature, the usage of frequency resources is variable, complex and difficult to characterize. In particular, with the development of satellite-borne phased array antenna technology, SatCom beams carrying different frequencies are directionally and dynamically distributed in global scale. Mapping and locating the spatial beam distributions of communication satellite (comm-satellite) are the bases of intersystem cofrequency interference mitigation and spatial frequency reuse. In this paper, we design a data selection–multiparameter fitting iteration (DS-MFI) algorithm on the basis of ground-based omnidirectional antennas. The proposed approach can effectively map the spatial distribution of comm-satellite's beam, including satellite transmitter position, equal-gain off-axis angle, and beam pointing in azimuth and elevation. Simulation results verify the effectiveness of the proposed approach for satellites with fixed or steerable beams at different altitudes. Furthermore, the results become increasingly accurate as the dense of ground omni-antenna increases. 相似文献
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提出并实现了一种利用卫星信标信号来实施基于相控阵天线的波束跟踪算法。该方法适用于采用相控阵天线技术的各种卫星"动中通"天线,克服了卫星信标信号强度弱,检测困难的弱点,提高了跟踪信噪比,同时采用了软件无线电方式解调可以提供最大的灵活性。跟踪算法的最大优点是没有任何陀螺仪的辅助,极大地提高了天线在各种极端运动环境下的适应能力。算法最终在自行研制的Ku波段相控阵移动卫星天线系统上获得验证。 相似文献
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This paper presents the parametric design and analysis of multiple-beam reflector-antenna systems employed for satellite communications. It is based on extending the earlier work of Rao (see IEEE Antennas and Propagation Magazine, vol.41, no.4, p.53-59,1999) by taking into account the efficiency of the horn and pointing error of the satellite in the design of the multiple-beam antennas (MBAs), and by analyzing the edge-of-coverage directivity and co-polar isolation (C/I) performance. Design and analysis equations are developed for the multiple-beam antennas using offset parabolic-reflector antennas by including various design parameters such as the number of reflectors, the number of frequency cells, the focal-length-to-diameter (F/D) ratio, the horn efficiency, and the pointing error. The analysis employs a quasi-Gaussian beam representation for the primary and secondary patterns in order to take into account the effect of the sidelobes. Results of the analysis given in this paper agree well with rigorous computations based on physical optics analysis of the antenna radiation. Design curves showing the impact of horn efficiency on the C/I performance of multiple-beam antennas are presented for various frequency-reuse schemes. 相似文献
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一种实用新型宽波束圆极化天线 总被引:1,自引:0,他引:1
圆极化天线是一种应用非常广泛的天线形式,尤其是在卫星通信和卫星定位设备中,随着这些系统的发展,对天线提出了越来越高的要求,低剖面、宽波束覆盖的圆极化天线越来越受到追捧,本文提出了一种新型宽波束圆极化天线—双臂螺旋天线,该天线3dB 波束宽度可达160°以上,具有结构简单、尺寸小、性能稳定等优点,可以广泛应用于各种军用、民用通信领域。 相似文献
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超密集低地球轨道卫星通信网络能弥补传统地面网络频谱资源稀缺、覆盖范围有限的不足,有潜力提供全球大规模接入的高速率服务。由于卫星的高速移动性,卫星通信对天线性能,如波束控制能力和天线增益等,也提出了更为严苛的要求。因此,对一种新型的超材料天线——可重构全息超表面(reconfigurable holographic surface,RHS)辅助卫星通信展开了研究。RHS采用全息原理对超材料单元进行电控,从而实现波束成形。基于 RHS 的硬件结构和全息工作原理,提出了一种 RHS 辅助多卫星通信方案,该方案同时考虑卫星跟踪和数据传输。同时,设计了全息波束成形优化算法以最大化和速率。仿真结果验证了所提方案的有效性并表明了相较于传统相控阵天线,RHS提供了一种成本效益更高的卫星通信支持方式。 相似文献
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卫星光通信终端CCD成像光斑弥散圆尺寸选择 总被引:2,自引:0,他引:2
利用CCD对自由空间传输的激光进行成像,可得到入射光束的角度信息以实现对发射光束的控制。卫星光通信中,提高对入射光束角度偏差实时测量的精度,可以有效地提高终端的光束跟踪性能,进而有效地保持激光链路的稳定。通过分析角度偏差检测原理,建立了卫星光通信中跟瞄装置测角性能分析模型。分析了测角精度与CCD成像光斑弥散圆尺寸之间的关系,并通过模拟实验进行了验证。结果表明,在卫星光通信系统设计中,综合考虑测角精度要求、终端功耗限制等因素,选择CCD成像光斑相对尺寸在2到3之间为最佳。 相似文献