基于串扰与干扰源相位同步的减小串扰研究

基于串扰信号相位改变与干扰源信号相位改变具有同步的特性,提出了一种在干扰线中点利用信号反相来减小串扰的方法。n条总线系统中,在编号为奇数(或者偶数)的传输线中点插入反相器,使每条传输线在前二分之一耦合长度和后二分之一耦合长度上获得的远端串扰信号幅度相等、相位相反,前后两部分耦合长度所产生的串扰信号经过自动叠加后,传输线上的远端串扰就会被抵消。仿真结果表明:所提出的方法能够明显抵消串扰。     

高速PCB中传输线串扰的研究与仿真

文章分析传输线串扰形成机理,使用Hyperlynx仿真软件构建串扰模型,分析影响近端串扰和远端串扰饱和的因素。仿真结果表明,传输线类型及耦合长度、线间距、攻击线数目、信号上升/下降时间、介质厚度、介电常数等因素对近端串扰和远端串扰均产生较大影响。最后在理论及仿真结果的基础上,总结出高速PCB设计中抑制串扰噪声的实用措施,具有一定的工程指导意义。     

基于HFSS的高速不连续性微带线串扰分析

建立了高速不连续性微带线HFSS(High Frequency Simulator Structure)串扰仿真分析模型,基于该模型对不连续性微带线在高频条件下的串扰问题进行了研究,得到了其近端串扰(S13)和远端串扰(S14),分析了信号频率、微带线厚度、微带线宽度、微带线宽度微带线拐角类型、微带线间距对串扰强度的影响。结果表明：不连续性微带线串扰强度随着信号频率的变化而呈现先增大后趋于平缓的趋势;近端串扰S13随微带线厚度的增大呈现递增的趋势;近端串扰S13随微带线宽度增大而增大;微带线拐角类型为圆弧时串扰最为明显;串扰强度随微带线间距增大而减小。基于研究结果提出了抑制不连续性串扰的方法。     

5类电缆性能测试的基本指标

结构化布线工程的最后一步是对布线系统的测试和评估，电缆的性能测试经常被忽视，基本指标有：近端串扰，综合近端串扰，衰减串扰比，等效远端串扰，综合等效远端串扰，回波损耗，延迟抖动等。     

高速数字电路PCB中串扰问题的研究与仿真

针对高速数字电路PCB中传输线间串扰的严重性,从精确分析PCB中串扰噪声的角度出发,在传统的双线耦合模型的基础上,采用了一种三线串扰耦合模型。该模型由两条攻击线和一条受害线组成,两条攻击线位于受害线的两侧,线间采取平行耦合的方式。利用信号完整性仿真软件Hyperlynx对受害线上的近端串扰噪声和远端串扰噪声进行了仿真。仿真结果表明,不同的传输模式和传输线类型、信号层与地平面的距离、耦合长度、传输线间距和信号上升/下降沿等因素会对受害线上的近端串扰和远端串扰产生较大的影响。在分析仿真结果的基础上,总结出了高速PCB设计中抑制串扰的有效措施,对高速数字电路设计有一定的指导意义。     

高速数字系统的串扰问题分析

在高速数字电路设计中,信号完整性问题越来越突出,已经成为高速电路设计工程师不可避免的问题.串扰问题是信号完整性问题中的重要内容.分析串扰产生的机理,讨论各种影响串扰的因素,建立了两线串扰模型并采用Mentor Graphic公司的信号完整性分析软件Hyperlynx进行了仿真实验.仿真结果表明:耦合长度、线距、信号的上升时间以及介质层对两线之间的串扰都有直接影响,在仿真研究的基础上针对以上因素的影响提出减小串扰的有效措施.     

防护线减小微带线间串扰的FDTD分析

随着信号转换速度日益提高,高速电路设计中的串扰问题也日趋严重。该文分析了使用防护线减小PCB微带线间串扰的效果,并运用FDTD对长耦合微带线进行了仿真验证。仿真结果表明,只要:(1) 添加有接地过孔的防护线并使过孔间距小于信号在RT/2(RT:传输信号的上升时间)时段内的传输距离;(2) 在满足线间距布线规则的前提下,将防护线适当加宽而又维持三条线(防护线和两条微带线)中两两之间的中心距不变,就能够有效减小线间的远端和近端串扰。     

PCB上串扰的耦合机理和优化分析模型

本文从频域与时域两个方面分析了PCB上的串扰的耦合机理,探究了耦合电容以及近端和远端电阻的影响。针对2-π串扰电路模型所提出的时域上的数学优化模型,明确了信号上升沿对干扰输出的影响。并且利用Hyperlynx软件包进行仿真,比较了耦合电容、耦合长度等的作用结果,仿真结果证明了理论分析的正确性。     

衬底材料对微带线间串扰耦合的影响研究

随着系统频率的提高,衬底材料特性已成为影响信号走线之间串扰的一个不可忽略的因素。该文基于传输线方程和频域S参数对两平行微带线间串扰耦合进行理论分析,并结合全波3维电磁场仿真工具对具有不同介电常数和不同厚度的衬底材料进行了仿真和分析,得到了微带线在不同衬底下的电场分布,以及近端和远端串扰随频率、衬底介电常数和厚度变化的曲线。随着频率的增大,远端串扰将大于近端串扰,并且随着衬底介电常数和厚度的增加,微带线间的串扰呈现正弦上升的变化趋势。     

“单端—差分”微带线串扰仿真分析

运用电磁场仿真软件分析"单端-差分"微带线结构的串扰问题。结果表明:增加单端干扰线和被干扰差分对的间距,可以同时减弱差分对的近端串扰和远端串扰;单端线和差分对间添加防护线可大幅减少远端串扰,且近、远端串扰均低于40 dB;改变防护线与单端干扰线及被干扰差分对的间距,差分对的近、远端串扰变化不大。     

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.     

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.     

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.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks