比较NEBS与CE认证中的EMC要求

在CE认证的基础上,从EMC方面介绍分析NEBS要求(按Level3级)与其区别,以便改进现有设计并在产品中考虑到NEBS需求,更好地满足北美市场的需要.主要比较静电放电、辐射抗扰、电快速瞬变/脉冲群、浪涌(冲击)、传导抗扰、稳态电力线感应抗扰度、DC电位差抗扰度、AC/DC失效测试、机架EFT测试、机架浪涌测试,以及传导发射、辐射发射等项目.     

TS9980测试系统S1测量不确定度的评定

文章从对比介绍随机误差与系统误差开始,引入测量不确定度的概念,并分析了测量误差与测量不确定度的区别.文章以EMC测试中的抗扰度测试为背景,详细进行了一次音视频产品抗扰度特性测试的不确定度分析.说明了测量不确定度在测量结果的表达中具有重要的作用.     

抗扰度测试

在开发实验室中进行辐射场抗扰度测试非常困难,但现在已经开发的大量小测试室却能解决这个问题。EMC指令(EMC Directive)提出了商用设备对射频场抗扰度的测试要求,这对大多数生产厂家来说是一个全新的要求,他们发现标准的抗扰度测试过程非常麻烦和昂贵。另外还需要可校准的无反射屏蔽室以保证被测产品在均匀、可重复的场中完成测试。     

欧盟发布新版EN61326标准 增加新要求

首先,新版标准规定了辐射抗扰度测试的频率范围是80MHz～2．7GHz。而在以前,标准中并没有专门规定测试频率范围,只是要求选择测试频率范围。除此之外,新版标准伍电压跌落和短时中断（VDI）测试等级上有所变化。最后,标准对由EN61426-1管理的产品的EMC抗扰度性能指标提出了明确的定义。在原有的标准中,厂商也可以任意选择抗扰度性能指标。     

电信设备及其技术

Y2000-62358-71 0016650非屏蔽电信端口上发射与抗扰度用的极限、测试方法和阻抗稳定化网络=Limits,test methods and ISNs foreminion and immunity on unshielded telecommunicationports[会,英]/Stecher,M.//1999 International Sympo-sium on Electromagnetic Compatibility(EMC’99).—71～74(PC)Y2000-62358-75 0016651采用 ISDN 基本接口的电信设备的 EFT/B 抗扰度测试情况=EFT/B immunity test conditions of telecommu-nication equipment using ISDN basic interfaces[会,英]/Kanno,S.& Miyashita,S.//1999 International Sym-     

电信网络设备9～150 kHz的传导EMC要求

介绍了在国际电联SG5中对于低频9～150kHz的传导骚扰和抗扰度的试验等级和测试方法。这对于电信设备的低频EMC又提出了新的要求，可供其它产品EMC标准借鉴。     

EMC认证的检验项目

家用电器产品EMC认证进行的EMC检验项目包含电磁发射(EMI)和电磁抗扰度(EMS)两个方面。电磁发射(EMI)的检验项目有:①.连续干扰电压(150kHz～30MHz);②.断续干扰电压(150kHz、500kHz、1.4MHz和30MHz);③.干     

EN 61000-6-1标准升级

通过与 EN 61000-6-1:2001的比较,介绍最新的欧盟电磁抗扰度通用标准 EN 61000-6-1:2007,指出相关电磁抗扰度测试项目和测试规格的更新,为电子产品出口企业和 EMC 测试实验室提供参考。     

提高集成电路电磁兼容性的研究方法

为提高集成电路的电磁兼容性能,科研人员一直致力于测量方法、预测寿命和工艺技术等领域的研究.文章基于已发表的50余篇文献,从电磁屏蔽、芯片布局优化、滤波、扩频、测量优化、发射预测、抗扰度预测和EMC感知组件选择等方面,综述了近几年IC EMC领域的最新研究成果,旨在为IC EMC设计人员提供参考.     

复合无线电设备的电磁兼容要求

大量的具有多种无线电发射技术或功能设备的出现,对现有的电磁兼容(EMC)测试提出了一个新的课题,即如何使用或联合使用现有的各个产品族或技术领域的EMC标准来规范或进行EMC测试.文中归纳了复合无线电设备的种类和复合状况,根据不同的组合类型,对如何进行骚扰和抗扰度测试提供了参考思路和依据,并列举了各种类型复合无线电设备的实例.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.