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为了量化电磁干扰程度,指导电缆布线设计,并判断设计中给出的电磁兼容措施是否满足系统及系统间的电磁兼容性要求,采用Ansoft Maxwell电磁仿真手段,做了不同种类线缆之间的电磁干扰仿真分析,得出信号线缆屏蔽层在接地良好的情况下,主要对电场起屏蔽作用,磁场屏蔽需要使用高磁导率的金属隔板.本次仿真具有工程性强、应用时象新等特点. 相似文献
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关于合成孔径激光雷达中微弱光电信号的检测技术,分析了PIN光电二极管的主要噪声来源,设计了偏置电路和滤波电路;鉴于高频效应的影响,合理使用电磁屏蔽等措施。实验结果表明PIN电路的设计和电磁屏蔽的使用有效减小系统噪声,提高了信噪比,为合成孔径激光雷达的实际应用提供了依据。 相似文献
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电磁屏蔽是保证建筑物内部电子信息系统正常运行而不受雷电干扰的重要措施,这种作用大小用屏蔽效能来度量。通过对常见电磁屏蔽效能的几种测量方法的原理、适用范围、优缺点的对比分析,结果显示:在屏蔽室尺寸为1.5~15.0m之间的长方形,测试频率范围与雷电流频率基本一致时,大环法的屏蔽效能测试值能较好地反映电磁屏蔽的效果;采用大环法对非理想形状屏蔽体屏蔽效能的检测,一定程度上解决了非理想形状电磁屏蔽效能检测的方法问题,具有一定的应用和推广价值。 相似文献
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某雷达机柜的电磁兼容设计 总被引:3,自引:0,他引:3
以某雷达伺服接收机柜为实例,介绍了电磁兼容的设计与实现。从线路和结构角度综合考虑,结合电磁屏蔽理论,对系统内和系统间的电磁兼容性进行了分析控制,达到了整机电磁兼容的目的。 相似文献
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YOLOv5s是计算机视觉深度学习算法中一种高效的目标检测模型。相较于R-CNN系列算法,极大地提高了检测速度和准确率。本文基于该算法设计了一个广播电视值班人员到场检测系统,通过对机房拍摄到的画面进行实时处理分析,并在系统中加入区域黑场屏蔽、差错规避、入库数据统计删查、摄像头断线重连等几种有效机制,降低了系统检测数据,提升了系统的检测效率和检测精度,实现了对人员到场情况的自动检测并提醒。系统方案准确率高,且适用度广,极大提高了机房值班运行的可靠性,保证了安全播出。 相似文献
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介绍了一个运用计算机检测和控制的导弹安全点火自动检测系统。分析了目前检测方 法中存在的不足,提出采用计算机自动控制和智能判断技术设计自动控制检测系统,完成对导弹安全点 火装置各种性能和参数的检查和测量。详述了自动检测系统的功能和特点,阐述了系统的组成、硬件设 计、软件流程以及系统工作原理等,并从系统供电瞬时、控制电路抗干扰及系统自检等方面,论述了设计 中所解决的关键问题。 相似文献
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ZHANG Hong-xin L Ying-hua BAO Yong-fang L Jian-gangSchool of Electric Engineering Beijing University of Posts Telecommunications Beijing P. R. China 《中国邮电高校学报(英文版)》2005,12(3)
1 Introduction For its good shielding and flexibility properties ,braided shielding cable is widely used in modern com-munications[1 ~2]. Because there are diamond shapedholes onthe shield,the magnetic fieldthat generated bythe current onthe shield goesintothe cable throughtheholes. On the other hand,the magnetic filed that gen-erated by the inner conductor current penetrates theholesinto the outer space . The electromagnetic leakagewill occur due tothe diffusionthroughthe metal andthefield pe… 相似文献
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随着平台一体化及雷达系统微型化的发展,调频连续波(FMCW)雷达发射至接收的信号泄漏更为严重,信号泄漏已成为制约FMCW雷达系统性能的关键因素。为解决这一问题,提出了一种新型的射频对消方法以提高FMCW雷达的收发隔离度,利用FMCW雷达泄漏信号与回波信号在频域可分离特点,采用数字锁相环技术产生主动对消矢量信号,在给定FMCW雷达泄漏信号初值的条件下仿真分析对消比与相位误差、幅度误差的关系,建立了特定条件下的具有自适应功能的射频对消方案,并设计了验证电路以验证方案的可行性。验证结果表明该方法在1 GHz带宽内实现了优于25 dB 的对消比,且该对消电路具有低功耗、结构简单等优势。 相似文献
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Analysis on effectiveness of wave absorbers to improve DSRC electromagnetic environment on express highway 总被引:1,自引:0,他引:1
Electromagnetic (EM) wave absorbers have been used for improving the EM environment of an electronic toll collection system on an express highway or a wireless local area network system in an indoor environment. In this paper, an efficient multiray propagation model, which uses three-dimensional geometry and image techniques to trace multiple signal rays from transmitter to receiver, is employed to analyze the EM environment of a dedicated short-range communication (DSRC) system on an express highway. The validity of the model employed is discussed by a comparison with the results obtained by an experiment on the highways when a right-circular polarized transmitter and receiver are used. The analysis shows that the possible undesired communications between onboard equipment that acts as a receiver and DSRC beacon, which transmits the radio signals, is improved by increasing the EM wave-absorption capability of the sidewalls and the pavement of the highway. Another advantage of the employed model is that it is effective for investigating the location of wave absorbers to be set up on the highway, and it takes only a fraction of a minute for computation. 相似文献
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伪随机码调制连续波雷达泄漏信号抑制途径 总被引:1,自引:0,他引:1
介绍了连续波雷达针对泄漏信号的设计考虑和几种比较实用的泄露信号抑制方法。泄漏问题是连续波雷达设计必须考虑和解决的,接收前端增益应根据泄露信号电平来设计,天线的隔离度应保证接收机工作与线性状态。几种泄露抑制方法大多做过专题试验,可供参考。 相似文献
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随着电磁环境的日益恶化,电子元器件对电磁兼容的要求也越来越高。如何提高电线电缆的电磁屏蔽效果,减小电磁干扰也越来越受到电线电缆行业的关注。为此主要对电磁波、电磁干扰、屏蔽机理、屏蔽设计、屏蔽材料等内容进行了探讨。 相似文献
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The jammer cross modulation (XM) transferred from a transmitter (TX) CDMA leakage by a receiver circuit is analyzed using the Volterra series and statistical theory. The measured "double-hump" XM spectrum is explained based on the CDMA signal statistics derived using the proposed system model of a reverse-link CDMA signal. The analysis shows that the XM distortion is affected by the circuit behavior not only at the jammer and the TX leakage frequencies, but also in the CDMA signal baseband and at the sum and difference of the excitation frequencies. This theory was verified on a 2-GHz Si bipolar junction transistor low-noise amplifier whose out-of-band terminations were optimally tuned to significantly reduce its XM distortion. 相似文献
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《Electromagnetic Compatibility, IEEE Transactions on》1986,28(1):40-45
This paper presents experimental data that show an over-whelming dependence of system electromagnetic compatibility (EMC) on system cable effects, rather than leakage through cracks, seams, and other box (LRU and WRA) openings. A laboratory experiment compares cable-shield RF leakage from a pigtail-terminated cable with that of one that has been terminated peripherally. Theoretical justification for these empirical observations is presented. That a shielded conductor carrying an RF current i induces its own return current -i on the inside surface of the shield is proved. By confining this return current to the inside of the shield, external emissions are attenuated by the intrinsic shielding effectiveness (which can be quite a large number) of the shield. 相似文献