小型机载光电平台电磁屏蔽设计

复杂的战场电磁环境严重影响了机载光电平台的安全性、可靠性和技术指标。为了提高小型机载光电平台的战场工作效能,从屏蔽的角度出发,对其进行了电磁兼容性设计。首先阐述了电磁屏蔽的屏蔽效能,并分别从屏蔽材料的选择、ABS外壳屏蔽、缝隙处屏蔽及敏感单元双层屏蔽等方面对小型机载光电平台进行了电磁屏蔽设计。通过电磁兼容性试验对屏蔽效果进行了验证。试验结果表明,采取合理的屏蔽措施后,小型机载光电平台的视频图像显示正常;传导发射值降低了约20 dBV;电场辐射发射值降低了约10 dBV/m;并且其余各项试验均得到了不同程度的改善。为机载光电平台电磁兼容性设计提供了参考。     

光电侦察平台电磁屏蔽设计

为了使光电侦察平台满足现代战场复杂的电磁环境要求,对某型光电侦察平台进行了电磁屏蔽设计。电磁屏蔽技术是抑制辐射干扰、提高系统电磁兼容性的最有效手段之一。分析了光电侦察平台在进行电磁屏蔽时的技术难点,根据其特有的技术难点,提出了一些实际可行的解决措施。对改进后的光电侦察平台进行了电场辐射发射（RE102）试验测试。测试结果表明经过合理的电磁屏蔽处理,可使光电侦察平台电场辐射发射值降低约10 dBV/m,提高了光电侦察平台的电磁兼容性。综合采取屏蔽、接地及滤波等技术手段,可使光电侦察平台的电磁兼容性满足GJB151A-1997中的规定。     

屏蔽室传导电磁环境电平超标问题及解决方案

<正>在按照GJB 151B-2013《军用设备和分系统电磁发射和敏感度要求与测量》执行电磁兼容性检测时,经常存在屏蔽室电源线传导发射环境噪声抑制不足的问题。具体而言：国军标要求屏蔽室电磁环境电平应控制在至少低于传导发射项目规定的最严格限值6 dB,以避免电磁环境影响测试结果。实际屏蔽室建设过程中,若对电源线传导发射CE101(25 Hz～10 kHz)和CE102(10 kHz～10 MHz)两个项目的环境噪声电平控制不加以重视,则往往无法满足标准要求。该问题在400 Hz电源应用场景上尤其突出,是一个长期困扰屏蔽室使用者和系统集成商的技术难题。     

开关电源散热器的辐射发射

开关电源电路中,接地散热器提供了一条共模骚扰高频谐波电流的通路,使共模传导电磁干扰增加;非接地散热器切断了共模传导电磁干扰的通路,但增强了散热器辐射发射,射频辐射的增强能够引起设备误操作或者违反目前的电磁兼容性标准.文中分析功率开关管散热器产生辐射发射和共模传导电磁干扰的机理.采用有限元方法,通过电磁场数值计算,探讨非接地散热器的几何形状、尺寸和安装方式对其辐射发射的影响.数值计算结果表明:散热器面积越大、高次谐波频率越高,辐射电场幅值就越大,但是辐射电场幅值与散热器面积、高次谐波频率无线性关系;相同面积的散热器中,圆形散热器的散热效果最佳、辐射电场最小.因此,开关电源设计中,应根据散热效果、辐射EMI和共模传导EMI,综合考虑散热器面积、形状的选择,以及散热器是否接地.     

EMC检测领域中电磁干扰的机理与抑制

电磁兼容性(EMC)是指设备或系统在其电磁环境中符合要求运行,并不对其环境中的任何设备产生无法忍受的电磁干扰的能力。因此,电磁兼容检测及整改是一项非常重要的工作。本文主要介绍了传导,辐射发射超标产生的原因及整改抑制措施,并通过一整改案例对整改措施进行了有效的验证。本文对产品的辐射,传导发射超标的整改具有有效的参考作用。     

军用组合导航电磁辐射的分析整改及验证

军用惯性组合导航产品在按照GJB151B-2013标准进行电磁兼容测试时,发现电源线传导发射CE102与电场辐射发射RE102两项超出标准限值幅值,不满足交付条件.该文完成了对现有产品进行电磁兼容整改设计,首先针对问题频点进行分析,分析干扰源和耦合路径,再通过电源和接口滤波设计、电路优化设计、结构设计和线缆设计四个方向进行重新设计整改.对新设计的样机进行电磁测试,测试验证说明整改后电磁辐射满足标准要求.     

舰载轻型天线稳定平台电磁兼容设计研究

基于电磁干扰和电磁兼容理论,针对舰载天线稳定平台安装位置处于恶劣电磁干扰环境和它在试验过程中因电源线尖峰信号及其传导发射和电场辐射等引起的电磁兼容问题,提出了采用压敏电阻和瞬变电压吸收二级管(TVS)进行瞬态抑制。采用屏蔽、滤波和接地等技术降低电场辐射以及采用合理的器件进行电磁兼容设计,这些措施在试验及实际应用中取得了很好的效果。     

电动车的电磁屏蔽仿真验证

以某电动卡车的电磁场辐射发射(9 kHz~30 MHz)严重超标为例,从主要辐射源的位置特点出发,在理论上分析了切断辐射源与被测天线间直视路径可带来的电磁辐射性能改善,借助电磁仿真软件建立了简化的测试环境模型,并设计和评估了整改方案及其效果。仿真结果显示,整改后,卡车的电场辐射发射降低至7 dB,磁场辐射发射降低至22 dB。     

某无人机载雷达电源模块传导发射EMC设计

CE102是无人机载雷达内场电磁兼容性测试重要项目之一,目的是定量测试雷达电源线10kHz~10MHz频段内对外骚扰强度。针对某无人机载雷达电源模块在内场进行CE102测试中多点超标的问题,在说明内部电路原理基础上对存在的干扰源进行了分析,根据电磁干扰基本原理有针对性地采取了一系列干扰源抑制措施和耦合抑制措施,改进后的电源模块传导发射电平在0.5~10MHz有超过30dB的下降,并通过了CE102测试。所采用的传导抑制措施容易实施且具有通用性,为类似机载电子设备工程设计提供了参考。     

车辆与驱动电机系统的辐射发射关联性研究

驱动电机系统与整车电磁发射特性的关联性研究作为当下的研究热点,对揭示整车电磁发射机理以及降低电磁发射强度有重要意义。首先论述了驱动电机系统、车速、动力电池系统对整车辐射发射的影响;其次论述了搭载不同驱动电机系统车辆以及搭载相同电机系统不同车型车辆的发射特性;最后从系统级电磁兼容性设计角度提出了驱动电机系统的电磁兼容性设计方法。     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and sub-pixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.     

INTEGRATION OF OPTICAL AND WIRELESS NETWORKS

正For a long time,optical and wireless systems/net-works are developed in separate communities witha few attempts for in-depth convergence.In fact,it prom-ises many advantages to combine the optical and wire-less technologies in the levels of systems and networks.Recently,both academia and industry have made manyefforts to enter a new phase of development to take op-tical and wireless systems as fully integrated networks.To provide high bandwidth and reliable service for bothfixed and mobile users,a well-designed network must     

社长序言（英文）

正Happy New Year!As we step into a new year,we take a look back at the key feature topics covered in China Communications over the past 12 months and set out our expecta-     

云计算专题（英文）

正Cloud computing is a novel computing paradigm that utilizes remote cloud resources to achieve a high-performance computation.Cloud provides infrastructure,platform and software as different on-demand services.China has made remarkable progress in cloudbased products and operating system technology.The government,enterprises and research institutions are all active in the development of cloud computing-related projects.Despite the progress,many important problems     

Call for Papers—Feature Topic,Vol.12,No.3,2015

正Smart Grid Communications The electric power industry is undergoing profound changes as the industry aims to capture the promise of a smart grid for a sustainable energy future.Enabled by the advanced sensing devices such as Phasor Measurement Units(PMUs),increasingly powerful