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Ka频段卫星通信地空链路的大气衰减 总被引:2,自引:0,他引:2
在卫星通信系统的设计中,设计人员往往更关心降雨对电波传播造成的降雨衰减,而易忽略在一般情况下晴空大气对卫星通信地空链路微波传播的影响。但是当系统的链路余度较小、天线仰角较低的情况下,应考虑晴空大气造成的衰减。论述了 Ka 频段卫星通信链路大气衰减的计算方法,给出了计算结果,可供从事类似工作的相关人员参考。 相似文献
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提出一种具有稀疏波纹结构的波纹喇叭天线,仅有2圈波纹,结构简单,易于设计加工。通过对天线参数的设计优化,可实现平顶波束赋形,在±40°的波束赋形范围内增益优于5 dBi,天线副瓣优于-30 dB,整个工作频段内驻波比(VSWR)优于1.8,适用于高轨卫星星间通信。通过对一个Ka频段样品的加工、测试和结果比对,验证了该设计方案的正确性。 相似文献
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随着对地观测技术的快速发展,遥感卫星空间分辨力的不断提高,星地链路传输的信息量越来越大,码速率越来越高,数据传输频段已经由传统的X频段扩展到Ka频段,以满足海量遥感数据传输的需求。但Ka频段低轨遥感卫星波束非常窄,遥感卫星地面接收系统需要具备良好的跟踪性能,才能实现系统稳定的捕获跟踪,保证接收数据的质量。文中通过对跟踪方式和跟踪精确度方面进行分析和论证,优化捕获跟踪流程,实现对低轨遥感卫星Ka频段的捕获跟踪。文中提出利用S频段跟踪引导Ka频段跟踪的方式,高低仰角采用不同的优化流程设计,结合高分辨力对地观测系统重大专项的先期研究内容和某地面接收站进行了设计验证,结果表明,可实现低轨遥感卫星Ka频段的捕获跟踪,待时机成熟,可进行工程应用。 相似文献
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Ka波段功率PHEMT的设计与研制 总被引:1,自引:1,他引:0
报道了Ka 波段功率PHEMT的设计和研制结果。利用双平面掺杂的AlGaAs/InGaAsPHEMT材料,采用0.2 μm 的T型栅及槽型通孔接地技术,研制的功率PHEMT的初步测试结果为:Idss:365 m A/m m ;gm 0:320 m S/m m ;Vp:- 1.0~- 2.0 V。总栅宽为750 μm 的功率器件在频率为33 GHz时,输出功率大于280 m W,功率密度达到380 m W/m m ,增益大于6 dB。 相似文献
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At the World Administrative Radio Conference (WARC)-92, the 2.6 GHz frequency band was allocated to a group of East Asian countries including Japan. This band is being studied for use in mobile multimedia broadcasting. This paper describes the outline of a system for 2.6 GHz band mobile multimedia broadcasting services, together with its requirements. In particular, the effects of the broadcasting signals attenuation due to shadowing by buildings and foliage, and the signals deterioration due to multipath propagation and fading, must be taken into account in order to realize the 2.6 GHz band system. This study considers the economic and technical constraints related to the modulation schemes, transmitting power, satellite antenna reflector aperture, the gain of the receiving antennas and the scale of the satellites. The configuration of satellite hardware systems based on the channel plan, channel bandwidth, and other specifications is investigated taking into account of these constraints. For example, a bit-rate of 4.8 Mbps can be provided when a 2-ton class satellite bus is utilized. This indicates that 2.6 GHz band services are technically feasible 相似文献
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Chun Loo 《International Journal of Satellite Communications and Networking》1998,16(3):137-145
This paper describes an analytical derivation of the performance impairment of a non-coherent FSK signal and a coherent PSK signal due to fading caused by weather conditions at Ka band. Analytical results on the effect of signal phase variation on a coherent PSK signal are included. Numerical values in terms of probability of bit error are given for the two digital signals. These results should be useful to a system designer of satellite communications systems at Ka band. © 1998 John Wiley & Sons, Ltd. 相似文献
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Verma Susheel K. Shankar Girja Singh Deepak 《Journal of Infrared, Millimeter and Terahertz Waves》1994,15(1):179-187
Journal of Infrared, Millimeter, and Terahertz Waves - A balanced upconverter curcuit has been developed in planar transmission line configuration using NEC GaAs beam lead Schottky barrier diodes.... 相似文献
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Susheel K. Verma Girja Shankar Deepak Singh 《Journal of Infrared, Millimeter and Terahertz Waves》1994,15(3):559-566
A balanced upconverter circuit has been developed in planar transmission line configuration using NEC GaAs beam lead Schottky barrier diodes. RF power output of +1.6 dBm SSB is obtained at Ka-band when up converter is driven by +17 dBm IF and +20 dBm LO signal. 相似文献
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A hybrid tile approach for Ka band subarray modules 总被引:1,自引:0,他引:1
Sanzgiri S. Bostrom D. Pottenger W. Lee R.Q. 《Antennas and Propagation, IEEE Transactions on》1995,43(9):953-959
A “thin” array construction using tile module architecture is presented in this paper. Several transmit-only tile modules operating at 30 GHz have been fabricated. The tile module involves a layered construction that contributes to reduced array thickness, weight, and cost. In such layered construction, the radiating aperture, active devices, and signal distribution functions are placed in different layers and involve vertical interconnections. The subarray module described involves a hybrid construction in which conventional wire bonding is utilized for interconnecting devices to the signal distribution layers. As in conventional modules, the devices are mounted on the carrier plates and fully tested before insertion in the module. The radiating elements which are integral to the module housing are connected to the devices through electromagnetic coupling. This hybrid construction is a first step towards a fully batch-processed tile module architecture. The construction approach and the performance results at the module and array level are presented 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1975,63(9):1371-1373
The feasibility of full-band low-noise instantaneous amplification in Ka band has been demonstrated using a staggered-gain amplifier technique. A simplified analysis of the overall gain variations in this two-stage amplifier is used to calculate the minimum isolation levels needed to meet a maximum allowable ripple. Using this technique, 10 ± 2.2-dB gain has been obtained from 26.6-39.4 GHz. 相似文献
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研究了在Ka频段上,宽带微带到波导的转换技术。转换通过波导-脊波导-绝缘子探针-微带线的方式实现。这样的实现方式具有插入损耗小、可密封、装配一致性好、可靠性高的优点。文中给出了转换的设计方法及脊波导参数的计算公式以计算转换的各项参数。设计完成后采用电磁场软件进行优化仿真,并根据仿真结果制作实物进行测试。最后给出了转换实物的测试数据。从测试数据可以看到,转换在整个Ka频段内具有良好的性能,插入损耗小于0.3 dB,驻波小于1.5。还可针对具体使用频段进行优化,以进一步提高性能。文中提出的转换完全能够满足实际工程应用,具有良好的应用前景。 相似文献
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基于0.25μm GaAs pHEMT工艺设计了Ka波段单片压控振荡器,该压控振荡器采用源极正反馈结构,变容管采用源极和漏极接地的pHEMT管。通过优化输出匹配网络和谐振网络以改善输出功率和相位噪声性能,使用蒙特卡洛成品率分析对本设计的成品率进行分析和改进。版图仿真结果显示:芯片输出频率为24.626.3 GHz,输出功率为(10±1)dBm,谐波抑制大于19 dB,芯片尺寸为1.5 mm×1 mm。 相似文献
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A new flow control scheme improving performance of the future broadband satellite networks is proposed and analyzed in this paper. The proposed scheme is particularly suitable for the Internet-based services in broadband satellite networks. The complexity of the proposed scheme is comparable with the existing flow control techniques, as it does not require the additional information to be provided by either the satellite or the Earth stations. The throughput and the satellite queue size performances of the proposed scheme are mathematically analyzed and simulated. The results show the significant improvement in the proposed scheme comparing with the conventional window-based and rate-based flow control techniques. Such a scheme can be used in the future satellite networks, which are an important component in the global information infrastructure (GII). 相似文献
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M. J. Willis B. G. Evans 《International Journal of Satellite Communications and Networking》1988,6(3):301-311
Fade countermeasure techniques that can be applied to Ka band satellite communication systems are reviewed. Considered in detail are diversity, adaptive forward error correction, fade spreading, up-link power control and adaptive TDMA. The techniques are compared for their effectiveness at Ka band, and recommendations are made for operating systems. The two important control techniques of fade detection and fade control are discussed in terms of their ease of implementation for each countermeasure technique. Details of a planned experiment to evaluate the application of fade countermeasures to VSAT networks via the Olympus satellite are presented. 相似文献
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Paolo Chini Giovanni Giambene Sastri Kota 《International Journal of Satellite Communications and Networking》2010,28(1):29-57
Satellite systems represent a significant solution to provide communication services to mobile users in under‐populated regions, in emergency areas, on planes, trains, and ships. In all these cases, satellite systems have unique capabilities in terms of robustness, wide area coverage, and broadcast/multicast capabilities. This paper surveys current mobile satellite networks and services from different standpoints, encompassing research issues, recent standardization advances (e.g. mobile extension for DVB‐S2/‐RCS, DVB‐SH) and some operational systems (e.g. Globalstar, Inmarsat BGAN, Iridium, and Thuraya). The last part of this paper is devoted to qualitative and quantitative comparisons of the different mobile satellite systems to understand their characteristics in terms of services, capacity, resource utilization efficiency, and user mobility degree.Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Robert Howell Paul Thompson 《International Journal of Satellite Communications and Networking》1992,10(2):71-79
Measurements of slant-path attenuation and crosspolar discrimination, obtained from four satellite measurement programmes carried out at the BT Laboratories, Martlesham Heath, England, are described. The measurements covered frequencies in the range 11.3 GHz to 30 GHz, path elevations ranging from 8.3° to 29.9°, and were made using both circularly and linearly polarized signals. Cumulative distributions, derived from the measured data, are extrapolated to frequencies of 12.5, 14.3, 19.8 and 29.7 GHz and then combined to give statistics for a database of more than 20 years. 相似文献
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G. Jerinic J. Fines M. Cobb M. Schindler 《Journal of Infrared, Millimeter and Terahertz Waves》1985,6(2):79-130
GaAs IMPATT diodes are capable of generating 2 to 3 W simultaneously with 18–22% efficiency in the 33 GHz to 46 GHz frequency band. The design of the amplifier circuits which utilize these devices is discussed. The circuit design is based on a 3-step closed form algorithm. The first step is a passive circuit characterization with an automatic network analyzer. In the second step, a computer is used to generate diode device lines. The third step is load line synthesis for predictable operation. The resulting performance is described. 2 W over a 2GHz bandwidth was achieved simultaneously with a minimum gain of 12 dB. 相似文献