利用DECT技术构成的新型无线本地环路

无线本地环路系统是近年来兴起的接入系统之一，它具许多有线系统所没有的优点，本文提出了一种新型的无线本地环路系统，它将一点多址技术和ＤＥＣＴ无绳电话技术有机地结合在一起，以全无线方式数字化地实现了整个用户环路。它针对本地环路的特点，有效地降低系统成本，在我国有很好的应用前景。     

无线本地环路系统

无线本地环路系统（ＷＬＬ）是近年来发展起来的新技术，它向用户提供具有市话有线用户环路同等功能的电话业务，是一种低成本的无线传输系统。本文将介绍无线本地环路技术 发展背景、特点，并介绍无线本地坏路系统概况，最后介绍Ｍｏｔｏｒｏｌａ公司的ＰＡＣＳ（Ｐｅｒｓｏｎａｌ Ａｃｃｅｓｓ Ｃｏｍｍｕｎｉｃａｔｉｏｎｓ Ｓｙｓｔｅｍ）系统及我国发展无线本地环路技术的策略。     

数字无线本地环路

简要介绍了无线本地环路的基本概念，采用的数字技术，ＴＤＭＡ和ＣＤＭＡ无线本地环路系统的结构，并指出无线本地环路在减少成本，灵活入网，扩展网络等许多方面的优势，对几种无线本地环路的容量作了比较，对无线本地环路的前景作了展望。     

多址技术与无线本地环路系统容量分析

随着我国电信事业的发展，用户接入技术已成为人们所关注的问题，无线本地环路系统是用无线方式在有线网和用户终端之间传送信息的通信设备。多址技术是无线本地环路的重要技术环节，本文讨论多址技术与无线环路系统容量这一问题。     

多址技术与无线本地环路系统容量分析

随着我国电信事业的发展，用户接入技术已成为人们所关注的问题，无线本地环路系统是用无线方式在有线网和用户终端之间的传送信息的通信设备。多址技术是无线本地环路的重要技术环节，本文讨论多址技术与无线环路系统容量这一问题。     

无线固定接入系统

无线固定接入系统陈万复无线固定接入系统又称为无线本地环路系统。它把无线技术的特点和传统电话端局的功能结合起来，提供一种迅速简单的网络连接手段。简单地说，就是用无线电波把电话局交换机的用户接口和用户设备之间连接起来。它既为传统的有线电话网提供了一种十分...     

无线本地环路技术

所谓无线本地环路(WLL）,就是采用无线技术,接入本地公众网,向用户提供电信业务,通过建立无线本地环路系统,可使已建立电信网的运营商利用现有的交换机资源,快速开展和经济地提供电信业务,避免与有线线路安装和维护有关的瓶颈;对新业务运营商来说,无线本地环路系统可使之能因电信政策变化获得更多的机会,在市场竞争中有立足之地。     

应用扩频技术传送多媒体信息的无线本地环路系统研究

文章介绍无线本地环路的概念，对现存的无线本地环中技术中做了比较，在此基础上提出一种采用扩频技术传输多媒体信息的无线本地环路，并对系统做了原理上的说明。     

无线接入网

本文描述了接入网概念、无线接入技术和无线接入网－无线本地环路及其种类，并详细介绍了先进的ＱＣＴｅｌＴＭ（ＣＤＭＡ）无线本地环路系统。     

无线本地环路（WLL）技术及发展趋势

本文介绍无线本地环路（ＷＬＬ）系统的基本结构及其相关技术，指出无线本地环路ＷＬＬ的优势和关键技术，并就ＷＬＬ的现状和发展趋势作出分析。     

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.