基于光通信技术的相控阵雷达波控系统设计

本文针对相控阵雷达波束扫描特点,提出了一种基于光通信技术的波控系统设计方案,对远程时序信号光传输、时钟同步信号光传输、交叉点矩阵开关等技术以及波束形成和单元校正算法进行了描述,详细介绍了系统的同步设计,为光通信技术在大型相控阵系统中的更广泛应用提供设计参考。     

微波光子技术在雷达相控阵中的应用分析与展望

近年来,微波光子技术在雷达、通信和电子对抗中的应用得到了越来越多的关注。本文简单介绍了微波光子技术的发展情况和优势,对微波光子技术在雷达相控阵工程应用中存在的光电/ 电光转换损耗大、集成度低、通道一致性差、成本高昂等问题进行了探讨,给出了微波光子技术在雷达相控阵中三种典型的应用场景,并针对目前存在的问题,提出了促进微波光子雷达相控阵推向工程应用的关键技术,包括高效的电光/ 光电转换、高性能的射频光传输和光电混合集成等。希望通过关键技术的突破,促进微波光子技术在雷达相控阵中实现大规模工程应用。     

色散光纤在X波段光控相控阵雷达技术中的应用

介绍了色散光纤在X波段雷达信号的光控相控阵中的应用——光纤延迟线,建立了光控相控阵雷达通信系统的模型,采用外调制的方法把微波雷达信号调制到光信号上,运用光学软件Optiwave来建立光控相控阵雷达的仿真系统。其结果可以为色散光纤在X波段光控相控阵雷达技术中的应用提供参考。     

光控相控阵雷达发展动态和实现中的关键技术

本文讨论了光控相控阵雷达的原理和发展现状,介绍了光控技术在宽带宽角扫描相控阵雷达中的应用和优点,详细阐述了不同光实时延迟线(OTTD)的主要构成原理和技术特点,讨论了雷达微波信号的光调制技术和探测技术现状,指出了光控相控阵雷达技术可能的应用方向.文中重点讨论了光控相控阵雷达实现中需解决的关键技术,包括总体设计方案中的系统指标分配,雷达阵面结构设计时光器件温度特性的考虑,微波信号光纤传输中的幅相一致性、动态范围、非线性相位等,OTTD设计加工中的波束切换时间、插入损耗、隔离度、延时精度等.针对OTTD加工中难免存在的加工误差,文中提出了子阵OTTD与阵元移相器联合波控的方法.     

光电技术在相控阵雷达中的应用

介绍了光电技术在相控阵雷达中应用的可能性，讨论了用光电技术解决相控阵雷达中的信号分配问题最后，简述了系统对光电器件的要求。     

光纤技术在雷达系统中的应用

列举了光电子技术在现代雷达中的应用，并重点介绍光纤技术在相控阵雷达中的应用，指出了设计光纤传输系统的关键是设计合适的光纤传输适配器和使各路数据信号同时到达。针对相控阵雷达，具体介绍了子阵适配器和处理机适配器以及多路信号不同路径传输后的延时设计。该系统采用模块化的光纤传输适配器，可实现数据的实时传输和控制，并具有可扩展性，同时文中还介绍了一种较为实用和简单的方法，来解决光纤传输相控阵雷达系统同步信号的问题。该系统在实验过程中工作良好，在相控阵雷达系统中具有很大的工程意义。     

相控阵技术对电子情报侦察影响研究

针对相控阵雷达技术引起的射频信号复杂多变的问题,提出一种基于对雷达射频信号进行动态信号级仿真的雷达侦察数据分析方法.对典型相控阵雷达系统应用的相控阵雷达技术进行了分析,并运用Matlab 7.0仿真工具软件对相控阵雷达射频信号进行了实时信号级仿真,获得了射频信号模型,分析了相控阵技术对电子情报侦察的影响.     

微波新技术在现代相控阵雷达中的应用与发展北大核心CSCD

随着应用需求的不断发展和变化,相控阵雷达朝着超宽带、多功能、高性能和高集成的方向发展。为了适应这些发展需求,微波技术作为相控阵雷达重要的技术基础,也必须不断向前发展。本文首先论述微波技术与相控阵雷达之间的关系;接着介绍微波新技术在现代相控阵雷达中的典型应用,涵盖新型相控阵天线技术、新型收发组件技术、高性能微波固态发射技术、高集成综合馈电网络技术、射频隐身技术和微波光电子技术等多个方面;最后分析微波新技术在相控阵雷达中的应用前景和发展趋势。     

基于下变频TOF-TDC的飞秒级微波光子延时测量技术研究

提出了一种基于下变频的飞行时间-时间数字转换(TOF-TDC)原理的微波光子传输链路延时抖动测量技术,并详细地阐述了该技术的基本原理、系统构架以及参数设计等.该技术能以飞秒量级的测量精度以及大延时测量范围对信号延时抖动进行测量.环境因素导致的延时抖动严重地影响了高频模拟微波光传输相位传递,进而制约其在光控相控阵等领域中的广泛应用.所提出的延迟抖动测量技术从本质上解决了光传输链路在电子战、宽带雷达等宽带应用场合中稳相传输所遇到的一个基础性问题,具有很大的应用推广潜力.     

光子晶体及其在光通信中的应用研究

介绍了光子晶体的概念,分析了光子晶体在光通信中的主要应用,讨论了光子晶体光纤的光传输性质以及由光子晶体构造的光通信器件,指出了光子晶体对未来光通信技术发展的重要意义。     

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.