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新一代GPS卫星信号的研究 被引量:2
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作者 冯永新 周丹 +1 位作者 刘芳 潘成胜 《火力与指挥控制》 CSCD 北大核心 2009年第9期41-45,52,共6页
随着GPS现代化建设进程的不断推进,改善导航与定位精度、扩大服务覆盖面和改善服务持续性,提高系统安全性和抗干扰性、注重兼容与扩充等技术相继得到了应用与实施。为此,在分析新一代GPS卫星信号改进与变化的基础上,从包含新的信号调制... 随着GPS现代化建设进程的不断推进,改善导航与定位精度、扩大服务覆盖面和改善服务持续性,提高系统安全性和抗干扰性、注重兼容与扩充等技术相继得到了应用与实施。为此,在分析新一代GPS卫星信号改进与变化的基础上,从包含新的信号调制体制、新的军用伪码信号及其增强型应用,考虑兼容和新需求的民用伪码及新频段增设等方面进行了较为系统的归纳与深入地研究,进一步通过仿真分析验证了新一代GPS卫星信号的先进性和拓展性,从而为发展我国天基导航系统提供依据。 展开更多
关键词 GPS BOC TDDM 交互调制
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电缆电视科普讲座(十三)——第八章 电缆电视系统故障及其排除
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作者 董书佩 《电视技术》 1988年第11期43-45,共3页
电缆电视的故障表现在电视屏幕上虽然最直观,但却很杂复,往往是各种故障现象的综合反映。电视接收机接在电缆系统输出处,屏幕上所反映的故障现象有以下三个方面的原因:1.信号在空间传播过程中距离较远或者受到各种阻碍和干扰等;
关键词 左重影 干线放大器 电缆电视系统 输出电平 电视传输系统 电视信号 导频信号 交流声干扰 滚道干扰 输入电平 分配系统 天线馈线 天馈线 互调干扰 交互调制
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对CDMA和TACS网间干扰的探讨
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作者 杨其芳 《通信世界》 2000年第14期28-29,共2页
关键词 CDMA 联通 宽带发射 载频 TACS 杂散干扰 互调干扰 交互调制 阻塞干扰 强干扰阻塞 基站
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A low power quadrature up-conversion mixer for WSN application
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作者 吴晨健 Li Zhiqun 《High Technology Letters》 EI CAS 2013年第3期228-232,共5页
This paper presents an up-conversion mixer for 2.4GHz wireless sensor networks in 0. 181xm RF complementary metal-oxide semiconductor (CMOS) technology. It is based on a double-balanced Gilbert cell type. With two G... This paper presents an up-conversion mixer for 2.4GHz wireless sensor networks in 0. 181xm RF complementary metal-oxide semiconductor (CMOS) technology. It is based on a double-balanced Gilbert cell type. With two Gilbert cells it was applied quadrature modulation. Operational ampli- tiers are used in this design to improve the conversion gain under low power consumption. The mixer design is based on 0.18txm RF CMOS process. And the mixer test results indicate that under 1.8V power supply, with input frequency 2.4 - 2.4835GHz, the conversion voltage gain is 1.2 - 2dB. When the output frequency is 2.4GHz, its power gain is -4.46dB, and its input referred 1 dB com- pression point is -11.5dBm and it consumes 1.77mA current. 展开更多
关键词 MIXER low power Gilbert operational amplifier
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Influence of Air-Jet Vortex Generator Diameter on Separation Region 被引量:3
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作者 Ryszard Szwaba 《Journal of Thermal Science》 SCIE EI CAS CSCD 2013年第4期294-303,共10页
Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (v... Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (vane type) vortex generators and transpiration methods of suction and blowing. This investigation concerns interaction control using air-jets to generate streamwise vortices. The effectiveness of air-jet vortex generators in controlling separation has been proved in a previous research. The present paper focuses on the influence of the vortex generator diameter on the separation region. It presents the results of experimental investigations and provides new guidelines for the design of air-jet vortex generators to obtain more effective separation control. 展开更多
关键词 shock wave boundary layer separation control streamwise vortices air-jet vortex generator
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