高电流,高速缓冲器

图中所示电路是为相对大的脉冲型信号应用于一个标准阻抗(比方说50Ω)的情况而设计的。两个高速缓冲器的并联电路防止了在高负载和高驱动的情况下出现过热。使用的运算放大器是ＡｎａｌｏｇＤｅｖｉｃｅｓ公司的ＢＵＦ104型,带宽为110ＭＨｚ,旋转速率很高,为3000Ｖμｓ-1...     

SAD0820高速8位A／D转换器的设计与分析

ＳＡＤ０８２０高速８位Ａ／Ｄ转换器是一种具有跟踪／保持功能的８位高速微机兼容Ａ／Ｄ转换器，其转换时间为１．５ｕｓ，功耗为７５ｍＷ，用串并结构来实现Ａ／Ｄ转换器的高速。每４位ＡＤＣ分别由１５个比较器构成；单一电源工作，采用双层多晶硅ｐ阱ＣＭＯＳ工艺制作。     

结合D／A转换和FIR滤波的一种高速可编程CMOs接口系统

结合Ｄ／Ａ转换和ＦＩＲ滤波的一种高速可编程ＣＭＯｓ接口系统＝Ａｈｉｇｈ－ｓｐｅｅｄｐｒｏ－ｇｒａｍｍａｂｌｅＣＭＯＳｉｎｔｅｒｆａｃｅｓｙｓｔｅｍｃｏｍｂｉｎｉｎｇＤ／ＡｃｏｎｖｅｒｓｉｏｎａｎｄＦＩＲｒｉｌｔｅｒｉｎｇ［刊，英］／Ｈｅｎｒｉｑｕｅｓ...     

构建铜缆信息高速公路——EasyAccess DSL接入系统

全创通讯的ＥａｓｙＡｃｃｅｓｓＴＭＤＳＬ接入系统由安装在局端或光纤远端模块（ＯＮＵ）的ＡｃｃｅｓｓＥｘｐｒｅｓｓＴＭ１０００ＤＳＬＡＭ和安装于用户端的ＡｃｃｅｓｓＬｉｎｋｅｒＴＭ系列ＤＳＬＣＰＥ组成,在一条电话双绞线上,除了能为用户提供普通电话业务外,还能为用户提供高容量的交互式多媒体应用,如高速Ｉｎｔｅｒｎｅｔ访问、远程局域网访问、视频点播、视频流应用等等。ＥａｓｙＡｃｃｅｓｓＤＳＬ接入系统集成了采用ＤＭＴ调制方式的ＡＤＳＬ传输系统。ＤＭＴＡＤＳＬ传输系统由集成在ＡｃｃｅｓｓＥｘｐｒｅｓｓＴＭ１０…     

GaAs IC CAD及其在通信电路中的应用技术

介绍了自主开发的多个完整实用的ＧａＡｓ ＩＣ ＣＡＤ软件,包括微波无源元件建模、微波有源器件测试建模、微波毫米波ＩＣ ＣＡＤ、光电集成电路ＣＡＤ、ＧａＡｓ ＶＨＳＩＣ ＣＡＤ、微波高速ＭＣＭ ＣＡＤ等,并简要介绍了针对ＧａＡｓ工艺线的建库工作。以上软件和库已用于多个通信电路的设计。     

数字信号处理器在通信设备中的应用

数字信号处理器在通信设备中的应用张煦ＡｐｐｌｉｃａｔｉｏｎｓｏｆＤｉｇｉｔａｌＳｉｇｎａｌＰｒｏｃｅｓｓｏｒｓｉｎＣｏｍｍｕｎｉｃａｔｉｏｎＥｑｕｉｐｍｅｎｔ￥ｂｙＺｈａｎｇＸｕ数字信号处理器（ＤＳＰ）越来越多地得到广泛应用。它们是为高速、实时数值计...     

32kb／sADPCM中高速乘法器的设计

本文介绍了６０路３２ｋｂ／ｓＡＤＰＣＭ专用芯片中的高速乘法器的逻辑设计和提高运算速度的方法。通过优化设计，该乘法器运算速度高，电路简单，对芯片制造工艺要求不高。     

PADS-PowerPCB基于Windows的PCB集成设计系统

当众多的ＰＣＢ设计软件厂商刚刚开始推出基于Ｗｉｎｄｏｗｓ平台独立的ＰＣＢ设计软件的时候，ＰＡＤＳＳｏｆｔｗａｒｅＩｎｃ（比思软件公司）已经为广大的电子设计用户推出了真正的基于Ｗｉｎｄｏｗｓ环境的ＥＤＡ集成系统、ＰｏｗｅｒＳｕｉｔｅ集ＵＮＩＸ系统功能强大和Ｗｉｎｄｏｗｓ系统操作简便于一体，其核心软件ＰＡＤＳ－ＰｏｗｅｒＰＣＢ是基于Ｗｉｎ－ｄｏｗｓ的ＰＣＢ设计系统，具有规则驱动、动态布线、动态电性能检查、高速电路设计规则、全自动和交互式的簇布局工具和在线设计规则检查等特点，以下就详细介绍一下ＰＡＤＳ…     

ADC签约澳大利亚:世界最大的MMDS广播无线系统即将动工

全球领先的宽带综合服务网络设备、软件供应商———美国ＡＤＣ公司与澳大利亚最大的付费电视运营商Ａｕｓｔａｒ公司签约一个战略性项目 ,在澳大利亚布设当今最大的ＭＭＤＳ广播无线系统。系统中的双向传输设备将为澳大利亚６０多个城市提供高速网络和电话服务。工程于２０００年下半年开工 ,计划于２００１年第一季度投入使用。Ａｕｓｔａｒ的经理说 :“现有的基础结构不能为澳大利亚提供它们需要的服务。而Ａｕｓｔａｒ公司的目标就是为上百万的澳大利亚人提供一流的数字和语音服务。ＡＤＣ的Ａｘｉｔｙ 平台使Ａｕｓｔａｒ不受原有的同…     

GaAs IC CAD方法

本文重点论述ＧａＡｓ ＩＣ ＣＡＤ方法，包括：精确的ＧａＡｓ ＭＥｓＦＥＴ、ＨＥＭＴ和ＨＢＴ等有源器件模型；大、小信号模型参数提取；噪声模型；成品优化；高频、高速微带传输线模型；电路模拟与优化；砷化镓门阵等。还评述了ＧａＡｓ ＩＣ ＣＡＤ集成软件包及进一步工作。     

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.     

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.     

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.     

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.