手机电磁兼容测试常见问题分析及相关性能改进

针对手机电磁兼容测试中经常出现的问题,包括静电放电抗扰度试验、电快速瞬变脉冲群抗扰度试验、辐射骚扰及传导骚扰性能测试中经常发现的问题进行了分析,并提出了相应的改善手机电磁兼容性能的建议。     

电能表带载脉冲群抗扰度试验

介绍了电能表在进行电快速瞬变脉冲群(EFT)抗扰度试验时的一种脉冲个数测量方法.以交流稳压电源给带负载电阻的电能表提供稳定电压,用独立的计数器和定时器来计算脉冲个数.这种方法解决了由检定装置给电能表提供电压和电流时,因检定装置受到电快速瞬变脉冲群干扰而导致试验失败的问题.     

电磁抗扰性的测量（二）

介绍了电快速瞬变脉冲群和浪涌的试验方法.     

本期导读

时光似箭,日月如梭,转眼2006年已经优美地划上了一个句号。感谢广大作者和读者对本刊的关注与支持,衷心地希望能够继续得到你们的关心和帮助。2007年,我们计划编辑的栏目有:第1期安全与电磁兼容,本期将针对快速瞬变脉冲群对电子产品的影     

远方推出频率达1MHz的快速群脉冲发生器

远方公司自主研发生产的EMS61000-4A快速群脉冲发生器日前通过鉴定，该仪器完全符合IEC61000-4-4：2004、EN61000-4-4以及GB／T17626．4-1998的要求，它产生的瞬变脉冲群具有极短的上升时间，最高频率可达1MHz。     

电快速瞬变脉冲群抗扰度误码率测试系统方案

很多电子通讯设备在出厂时都会做电快速脉冲群瞬变抗扰度试验,但一般都只是测试设备是否被高压脉冲群损坏。本文介绍自主设计的系统,可以在高压脉冲群干扰的同时测试被测设备的通讯误码率。     

高速RS-485收发器快速瞬变脉冲群测试系统的设计

随着物联网技术和智能仪表的飞速发展,RS-485在新的领域内得到了更广泛的应用,随之而来的,也对RS-485收发器的可靠性与误码率提出了更严苛的要求.针对RS-485收发器快速瞬变脉冲群的测试,通常是基于系统,例如在低速的智能电表中完成的.本文介绍了一种高速RS-485收发器快速瞬变脉冲群测试系统的设计,可以作为一个通...     

EFT测试空间辐射特性的仿真及实验验证

在分析电快速瞬变脉冲群干扰信号理论模型的基础上,采用CST软件建立了相应的仿真模型,提取了不同空间位置的辐射场强,并通过相应实验测得实际测试环境中干扰信号所产生的空间辐射场强。结果表明,实验结果与仿真结果具有一定的吻合性,这说明EFT测试过程中会在空间产生一定的辐射电磁场。     

动车组供电母线与传感器信号线间串扰仿真

为了定量研究动车组电源线对速度传感器信号线缆的串扰影响,提出了基于时域有限差分理论的耦合模型。基于该模型,在电源线上施加电快速瞬变脉冲群干扰,分析速度信号受扰后的失真情况,并通过仿真定量地分析了脉冲群的重复频率对速度传感器信号线内所传输的信号的影响,得出速度信号的误差与脉冲群的重复频率成线性关系的结论。     

EFT测试干扰机理和辐射特性分析

根据IEC 61000-4-4:2012推荐的数学表达式,在时域和频域上分析了电快速瞬变脉冲群的干扰机理。采用基于光纤传输的瞬态电磁场测量系统对电快速脉冲群试验辐射场强进行了测试评估。给出了容性耦合夹水平面0~200 cm和垂直方向0~50 cm(在坐标为50 cm处和100 cm处)的辐射场强分布。     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

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.     

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.