无人机一站多机数据链技术

面向多无人机协同作战应用需求,在分析国内外一站多机技术体制的基础上,提出了一种基于数字多波束天线的一站多机数据链系统。系统中地面站作为地基无线路由器,单个波束构成的链路可以装载不同的波形及协议,实现多无人机协同工作,显著提高无人机的使用效能。分析了一站多机数据链系统军事需求并给出了系统的设备组成,重点从测控通信链路的角度分析了数字多波束天线、动态随机接入、链路动态重构、多无人机协同实时任务规划、网络协议体系等关键技术。相关内容可供无人机一站多机数据链系统顶层设计参考。     

应用无人机实现地面无线传感器网络通信中继的探讨

提出了应用无人机实现地面无线传感器网络远程通信中继的方案,对方案的可行性进行了分析,通过与卫星中继、有人机中继的比较具体论述了无人机通信中继的必要性和优越性。分析了系统的总体结构和作战信息链路,对整个系统的关键技术即数据融合技术和数据链技术进行了探讨,并针对战场应用提出了相关的设想,为应用无人机进行战场通信中继的预先研究奠定了基础。     

系留无人机中继通信系统研究

由无人机携带的通信中继装备(如基站、无线电台等)在提高网络容量、扩大网络覆盖范围方面具有巨大的潜力,但是却存在着因自带电源有限而飞行时间短、难以建立无人机与地面站间可靠通信链路等缺点,而系留无人机中继通信系统则可有效解决这些问题。文章描述系留无人机中继通信系统的构成,分析系留无人机中继通信系统的优势,指出系留无人机中继通信系统的缺点,介绍系留无人机中继通信系统的应用场景。     

通信

0317288无人机平台的超视距多链路中继〔刊〕/罗卫兵//遥测遥控.-2003,24(2).-32～35(C) 提出一种以无人机平台为基础的超视距多链路中继概念,它采用分层管理来提高无人机通信中继的灵活性和有效性,分析无人机通信中继的军事应用领域和主要应用优势,指出了平台存在的安全同题及提高低概率侦测(LPI)性能的措施。参6 0317289一种改进型扩频地址码ZCZ码的设计〔刊〕/狄旻//空军工程大学学报(自然科学版).-2003,4(2).-46～48(K)     

无人机无线电综合测控系统

<正> 无人机无线电综合测控系统是无人机系统的重要组成部分,采用地空视距链路,空中中继链路或卫星中继链路,分别实现对近程、短程、中程、远程无人机的遥控、遥测、跟踪定位和视频信息传输。系统由地面主测控站、机动测控站、视频接收站和机载设备等组成。     

中继式无人机自组网安全协议研究

为了提高无人机集群战术通信链路传输的连贯和安全,针对当今无人机自组链路网络的不足,提出了一种中继式无人机自组网安全协议.该协议将无人机集群划分为普通节点和中继节点,中继节点担任空间网络环境信息采集和分析的作用,并作为无人机集群协同化中心通过获得的信息为整个集群规划路径,此时新加入的无人机节点不会影响整个战术通信链路,保...     

应用于无人机中继测控链路的微波前端设计

当前无人机测控数据链系统多为点对点视距传输,当遇到需要扩展通信距离或存在障碍物遮挡时往往限制了链路的正常工作。针对此问题,提出了一种应用于无人机中继测控链路的微波前端设计方案。其空空链路与空地链路采用频率倒置的频分双工体制,有效避免了前向链路与返向链路的收发干扰,并实现了机载设备的硬件统型;通过软件注入便可完成对终端模式的在线切换,提升了系统应用的灵活性与鲁棒性,为保证复杂环境下无人机测控链路的实时传输提供了一种有效的解决途径。     

基于Google Earth的无人机中继布局优化软件

建立了一个无人机作为中继的通信网络系统,并通过对中继链路和高空中继覆盖区域进行几何建模,推导获得了无人机在一定飞行高度的信号覆盖区域。在此基础上,基于Google Earth和Visual C++6.0软件平台,开发了一套无人机中继系统可视化网络优化软件。测试结果表明,该软件操作简便且运行稳定,能够实现无人机的静态最优布置与动态飞行路径规划,对于解决网络节点高速和大范围移动导致的网络中断问题,具有重要的工程应用价值。     

多无人机测控系统研究

介绍了无人机侦察的作用和地位以及对无人机测控系统的要求,首重分析了实现多无人机测控系统需要解决的核心问题,提出了多无人机系统的空间定位方法,进一步深入探讨了中继式无人机系统的数据传输原理。     

无人机集群远程控制系统研究

无人机领域正在向着多机协同任务、集群任务的方向发展,但是目前无人机集群技术的研发多偏重于集群智能、集群算法的研究和无人机本身的设计,而缺乏对于集群任务下远程控制系统的研究。针对这样的现状,分析了无人机集群远程控制系统的必要性和需要实现的功能,从单机任务、多机协同任务、集群任务三个维度探讨了无人机远程控制系统的组成结构,并对无人机集群远程控制系统的整体架构和内部各组成模块的功能细节进行了详细介绍。该远程控制系统很好地符合了集群理论的技术特征需求,能够有效发挥无人机集群协作的优势。     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.