民航西北卫星网络综合保障研究

通过作者两年内对卫星设备运行保障工作的实践,结合民航西安TES卫星设备和KU卫星设备在实际运行中所遇到的两种典型故障,探讨卫星设备在信息网络综合保障中故障的分析和处理方法。     

卫星地球站上行干扰的排查与分析

0.前言 某卫星地球站（下文中简称“本站”）装有使用亚太6号C频段转发器的TES远端站设备、使用鑫诺1号卫星C频段转发器的TES远端站和PES远端站设备,以及使用亚洲4号卫星Ku频段转发器的TDMA设备。     

塔里木油田TES卫星远端站故障浅析

本文对塔里木油田卫星网络中的TES卫星远端站设备的故障进行了研究。描述了设备产生故障的表象,重点分析了故障的成因和排查故障的方法。     

TES网络系统

TES网络系统是休斯公司结合中国实际情况研制开发的一种VSAT通信网络，基于卫星的以全数字话音传输为主、兼具中低速数据通信的网状网，系统结构见图1。TES系统由许多节点（或称远端站Remote）和一个网络控制系统（NCS）组成。网络控制系统NCS提供网络管理与控制，是整个网络的核心，可位于任一TES节点。节点有两种类型：TES远端站及TES网关。TES网关支持多条信道进入公共网。TES系统支持网络内任意两个远端站间直接进行话音、同步及异步数据通信。远端站间直接传输话音和数据，因此卫星传输延时最小。系统中话音电路采用按需…     

浅析C波段卫星远端站系统维护工作

对民航C波段卫星TES系统和PES系统对工作原理以及系统结构功能进行阐述,根据实际工作经验,浅析C波段卫星远端站系统维护工作内容,从而提高了卫星系统的应急保障能力。     

卫星导航星座在轨测试系统总体技术研究

卫星导航系统主要由空间段导航卫星、地面段运行控制系统和接收机组成。在轨测试是在导航卫星发射入轨后对其各项功能及指标进行全面检验,判断是否满足卫星导航系统运行的要求。导航卫星在轨测试设备具有与地面运行控制系统相同的信号体制和基本功能,专业用于导航卫星的在轨测试。介绍了导航卫星在轨测试设备的组成,简单分析了利用该设备进行导航卫星在轨测试的方法,提出了一套行之有效的针对导航卫星在轨测试的方案。     

海上钻井平台通信UPS电源解决方案

近几年来,随着海洋石油在海上勘探、开发规模的不断扩大,海上钻采生产对通信的要求越来越高,除常规的短波通信设备外,TES卫星系统、程控交换机、计算机网络等通信手段在海上作业得到了广泛应用。通信是生产和指挥系统的中枢,也是船台应急、安全的重要保证。船用UPS就是要对上述设备提供优质、可靠的不间断电源,所以通信电源系统的质量和可靠性对船台是非常重要的。     

民航卫星通讯网络的定位和管理

民航卫星网是采用美国休斯公司的VSAT网,自1995年正式建立以来,远端站已发展到100多个,而且由于运行良好,每个远端站均进行了扩容,是目前民航系统节点最多,功能最强的通信网络之一.民航卫星网是由语音卫星通信网(TES)及数据卫星通信网(PES)两个独立网组成的.语音通信是通过单路单载波/按需分配(SCPC/DAMA)一跳完成接续;数据通信采用时分复用/时分多址(TDM/TDMA)两跳完成数据传输.全网均采用星状网和网状网相结合的拓扑结构,极为符合目前民航各类业务要求,具备了作为大型通信网的实力.     

广播电视卫星传输（连载六）

1．2．2．3运行可靠性 卫星业务对传输可靠性的要求越来越高．高功放设备是卫星传输系统中关键设备之一．其运行可靠性是维护工作者最为关注的问题。随着新技术的发展、新材料的使用和制造工艺的提高．目前高功放的运行可靠性有了极大的提高．应该说目前3种类型的高功放设备运行可靠性已经不逊于卫星系统中其它各种设备了。     

导航卫星有效载荷在轨测试系统设计研究

导航卫星有效载荷在轨测试是卫星入轨后的重要试验,通过在轨测试实现对导航卫星运行状态的全面检测。在轨测试系统可以全面模拟地面运行控制系统的功能,是检验导航卫星功能和性能指标的专用测试设备。针对导航卫星的工作原理对有效载荷的构成进行了简要介绍,根据被测对象,提出了在轨测试系统的设计方案,描述了系统设备组成及各设备的功能特点,并对在轨测试系统中的关键技术的实现进行了分析。     

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.     

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.     

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.     

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.     

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.