数字锁相实现ADSL系统中的时钟同步

文章提出了一种ADSL系统中基于离散多音调制解调结构的时钟同步方法。该方法根据锁相环的原理，充分利用了系统的现有结构，不需要专用的锁相环，降低了系统复杂度。实验结果显示，该方法精度高，自适应和抗干扰能力强。     

全相位FFT算法在机械传动测试系统中的应用

为了提高机械传动系统的测试精度和实时效果,构建了基于DSP及全相位FFT算法的机械传动测试系统,该系统由以DSP为核心的数据采集及处理的硬件结构和以全相位FFT算法为核心的数字信号处理软件组成.实验证明该系统具有抗干扰能力强、测量精度高、实时性好等特点.     

煤矿用远程数据采集与传输系统的设计与实现

介绍了煤矿用远程数据采集与传输系统的工作原理和软硬件实现方法,提出了改善数据远程传输方式的措施.现场试验数据表明,该远程数据采集与传输系统性能稳定,抗干扰能力强,具有一定的实用价值.     

某导弹测试设备电路板智能检测系统设计

针对某型导弹测试设备电路板故障缺乏行之有效检测方法的现状，设计了某导弹测试设备电路板智能检测系统。首先简单介绍了电路板检测原理，结合该设备电路板的结构和工作特点，建立了某型导弹测试设备电路板故障检测的模型，阐述了该系统硬件各功能模块的设计方案和系统软件实现方法；以典型的光电转换电路的测试为例，对电路板智能检测系统的进行了试验；试验结果表明，该系统能解决导弹测试设备电路板检测困难、测试效率较低的问题，提高了检测的效率和故障定位的能力，其性能稳定可靠，操作使用方便，结果显示直观；结合试验积累的经验，从两个方面对下一步继续研究进行了展望。本文网络版地址：http：//www.eepw. com.cn/article/273266.htm     

电源测试系统的设计和实现

介绍了一种基于虚拟仪器远程电源自动化测试系统，首先阐述了系统的工作原理，然后根据基本测试功能和主要技术指标设计了电源自动化测试系统，阐述了其组成模块测试接口箱和工控机测试装置的结构和设计方法。最后对测试系统软件进行了详细讨论。测试系统软件是在Windows环境下利用Borland C^ Builder5开发的，采用了模块化编程方法，该系统采取了抗干扰措施，大大提高了测试精度和测试效率，经过现场调试，现已投入运行，实现了电源系统的远程自动化测试。     

基于线性霍尔的摩托车曲轴转角测量研究

针对摩托车曲轴转角的高测量精度的要求,设计了一套基于线性霍尔元件的角度测量系统。文中给出了角度测量的原理,系统组成结构以及传感器信号的处理方法。实验平台测试证明该系统有效提高了曲轴转角的测量精度,且具有频率响应快,抗干扰能力强等特点。     

弹载红外图像实时编码器的设计

设计了适用于某型号导弹红外图像实时传输系统的关键部件图像数据编码器。为保证编码器的各项性能指标达到弹载设备的严格要求,本文重点在体系结构设计、芯片选型、PCB设计、系统抗干扰能力增强等几方面采取了多项针对性措施。设计与测试结果表明,该编码器结构简单,体积小,质量轻,功耗低,满足导弹研制任务对图像编码分系统各项指标要求。在工程实用中,该编码器性能稳定,工作可靠。     

炮弹引信动态信号自动检定系统设计

提出了一套引信动态信号自动检定系统的设计方法,该方法可使瞬态信号检测更加简单准确且易扩展。实际引信测试证明,该检定系统可靠性较高,而且抗干扰能力较强。     

电容放电式火工品发火电压检测仪

针对电容式放电火工品发火电压检测自动化生产的要求,设计了一种基于电容放电式的火工品发火电压检测仪,该系统硬件平台以单片机STM8为核心,集成了数控步进调压电源,电容放电发火电路模块,并设计了放电开关驱动电路以提高开关导通速度,提高电容能量的释放效率。实验结果表明该测试仪能模拟电容放电式火工品的发火过程,操作简便,满足其测试精度。     

基于CPLD的柔性直流输电信息传输系统的设计

设计了一种基于CPLD的信息传输系统,用于柔性直流输电阀控系统与下级子模块之间的数据交换.通过采用高速元件、冗余电路设计、软件算法优化等措施,使得该系统能够在保证数据快速响应的前提下,运行在高电压和强电磁干扰环境下.给出了系统设计的硬件原理图、软件流程图和测试波形.实际测试结果表明,该设计方案简单可行、抗干扰能力强,可以满足柔性直流输电系统信息的可靠快速传输.     

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.     

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 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.     

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.     

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