宽带信息化小区接入网建设及研究

分析了宽带信息化小区接入网采用FTTB／FTTC＋ADSL（VDSL、10BaseS、LAN）、FTTH等宽带接入技术的网络建设方案和宽带多媒体服务中心的建设,并对宽带信息化小区接入网建设提出了几点建议。     

智能小区与宽带接入网建设研究

伴随着我国通信技术以及计算机网络技术的不断发展,人们对智能化小区的要求也越来越高,主要体现在宽带接入网的建设方面。宽带接入网的建设是建设智能小区的关键举措,目前比较常见的宽带接入技术有WLAN、FTTx等,本文主要就这些宽带接入技术的优缺点进行分析,希望能够更好的解决智能小区的宽带接入问题。     

HFC接入技术在智能小区建设中的应用

简要描述了智能小区的基本概念和功能,着重分析了在智能小区建设中采用HFC接入方式的特点,详细介绍了利用HFC接入网构建智能小区宽带综合信息网络的解决方案。     

HFC接入技术在智能小区建设中的应用

简要描述了智能小区的基本概念和功能,着重分析了在智能小区建设中采用HFC接入方式的特点,详细介绍了利用HFC接入网构建智能小区宽带综合信息网络的解决方案。     

小区OLT建设必要性研究

全业务运营背景下,电信运营商正逐步加快宽带接入网的建设与优化,密集小区大量家庭客户的宽带接入催生了小区OLT的建设需求,文章通过对密集小区情况下集中式OLT和小区OLT建设的利弊进行比较并给出建设实例对比,指出了小区OLT建设模式的必要性。     

智能小区宽带通信接入网的实现

介绍了宽带通信原理及关键技术,并根据某小区宽带通信接入的需求分别介绍了该小区接入网的技术实现过程.     

基于GPON技术小区宽带接入方案的分析

GPON（Gigabit-Capable PON）是一种基于ITU-TG.984.x标准的最新一代宽带无光源综合接入标准。它具有高宽带、高效率、覆盖广的特点,并广泛运用于小区宽带网的建设中。因此,它是被称为实现接入网业务宽带化、综合化的理想技术。本文从GPON的定义出发,探讨了小区宽带接入采用GPON技术实现的可能性,并提出了基于GPON技术上实现小区宽带接入的具体方案。     

小区宽带通讯布线系统标准及产品质量验收检测

近年来，宽带接人技术与宽带接入网的建设受到我国电信行业制造商和运营高的高度重视，并且手段多种多样，如建立在电话线基础上的ADSL、vDSL等，基于光纤传输基础上的PON、APON、EPON等有源、无源光接人技术，光纤电视网、同轴电缆传输HFC系统及无线接入网，以及数据双绞线传输的以太网接人技术，其中ADSL接人和以太网接人被认为是普遍用于智能楼字企业网和小区宽带接人的手段。智能小区作为信息时代的产物，它应该通过建造一个宽带信息网络，把安防、     

宽带信息化小区建设

对于普通的用户来说,宽带网络的概念并没有实际的意义,用户真正感兴趣的是宽带能够带来什么样的服务。在宽带建设的初期,各个电信公司将注意力集中在宽带网络的基础建设上,与此相比宽带内容建设发展较慢,造成了网络建设投资巨大但用户稀少的局面。目前大家已经意识到宽带内容,尤其是宽带信息化小区服务内容的重要性。以下将介绍针对信息化小区的几项宽带业务：     

某宽带小区接入的选择及实现

文章从某小区数据接入网现状出发,对其宽带接入进行了设计,主要包括接入技术选择、组网方案及业务配置,满足了该小区用户的宽带业务需求.     

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.