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空基测控中继是为解决地面测控设备作用距离受视距限制的问题而提出的,而相控阵天线是空基测控中继设备的技术难点。根据实际需求,提出了相控阵天线的设计方案,对阵列形式、天线的流形、阵元间距、阵列规模以及阵元形式等进行了详细设计,并对天线的接收发射性能进行了仿真,对跟踪控制技术途径进行了阐述。所设计的相控阵天线增益可以满足约130 km、2 Mbit/s遥测数据中继,解决远距离低空飞行目标的靶场测控问题。 相似文献
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目前基于阵元间强耦合效应已设计出超宽带相控阵天线,但是其规模较大。针对规模小或者在扫描方向上规模小,如何增强阵元间耦合而实现超宽带相控阵天线的问题,采用平衡对踵Vivaldi天线(BAVA)作为天线单元,优化天线单元辐射金属的形状,并采用镜像法布阵天线单元设计出一个小规模4×16的斜极化超宽带相控阵天线。仿真和试验结果表明,采用的方法可以增强小规模超宽带相控阵天线的阵元间耦合效应,实现频率0.8f0~2.0f0驻波比小于2,法向增益达17.34~23.0 dBi,在±45°范围内实现无栅瓣扫描。该小规模超宽带相控阵天线已在实际工程中应用。 相似文献
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从信干比角度考虑,传统的全向辐射体制系统很难实现远距离抗干扰通信,而相控阵体制的高增益、低旁瓣特征可以使系统获得一定的抗干扰能力。从信干比分析入手,引入干扰概率指标,给出了一种针对抗干扰能力的统计分析方法,并进行了仿真分析,结果表明,由于阵面规模直接决定了方向图特性,而天线阵的体积、重量、功耗、成本均随阵元数目的增多而增长,所以在总体设计时需要对阵面规模进行折中考虑。该方法已成功应用于系统硬件总体设计。 相似文献
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针对后续靶场多发齐射等新型试验任务的测控保障需求,提出了基于全空域覆盖多频段综合孔径天线阵列、分布式数据采集与传输、多功能通用“资源池”为基础的新一代靶场多功能综合测控系统。针对靶场遥测常用的S频段和安控常用的P频段,给出了双频段共阵面全空域覆盖相控阵的具体实现方式,并仿真分析了核心指标。仿真结果表明,全空域增益波动在1 dB内,第一副瓣电平均小于-13.0 dB。此外,该系统架构具有可扩展性。 相似文献
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为满足一种星载系统的需要,研制了一双圆极化多波束对数周期天线(LPDA)阵,给出了该阵列的分析和设计方法.利用CST MWS电磁场计算软件对阵列单元以及组阵方式进行仿真和优化,减轻了设计风险,节省了设计成本,所得结果与实物测试具有很好的一致性. 相似文献
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《中国对外贸易(英文版)》2008,(5):50-51
The overall strategic relationship between U.K. and China is "better than ever", China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future. 相似文献
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Guo Yan 《中国对外贸易(英文版)》2008,(5)
Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit. 相似文献
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《中国对外贸易(英文版)》2008,(6):62-65
Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service & trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,"In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves." 相似文献
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Zang Kejia 《中国对外贸易(英文版)》2008,(7):16-17
When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years' experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year. 相似文献
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Estaing, former French president, Valery Giscard d'Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself"French Confucian", then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually "Partners". 相似文献
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《中国对外贸易(英文版)》2008,(5):12
The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy. 相似文献
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"If you are considering to trade with companies in Japan or expanding your business to Japan we are ready to help from the very beginning."You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization 《中国对外贸易(英文版)》2008,(10):16-17
If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning." You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization (JETRO). JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China's Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING. 相似文献
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Guo Yan 《中国对外贸易(英文版)》2008,(12):62-63
Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship, 相似文献
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Liu Xinwen 《中国对外贸易(英文版)》2008,(7)
Last year,the volume of China's auto trade reached US$66.878 bil- lion,of which imports accounted for US$25.982 billion,a year-on- year increase of 24.45 percent;while ex- ports totaled US$40.896 billion,growing by 45.31 percent.The China Association of Automobile Manufacturers(CAAM) predicts that the number of autos sold in 2008 will break the 1 million barrier for the first time in history,representing an increase of about 20 percent. 相似文献
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Guo Yan 《中国对外贸易(英文版)》2008,(1):10-10
In the middle of last December, the key purchase contracts for coal used in power generation in 2008 were signed, reflecting a demand for more than 1.085 billion tons. It is important to note that the country's five biggest power producers, China Huaneng Group, China Guodian Corporation, China Power Investment Corporation, China Huadian Corporation and China Datang Corporation, had settled on the prices on their purchase contracts, and they are expected to consume 290 million tons of coal for generating electricity, 相似文献