基于SysML的作战计划可视化建模

为达到作战意图,必须建立直观、易于理解的作战计划.借鉴军事概念模型的建模方法,运用面向对象的工程开发思想,给出了基于SysML的作战计划可视化建模方法,提出了可视化建模规则,并运用Rational Rose平台进行实例说明.可视化作战计划将大大加深军事人员对计划的直观理解和对战场态势的总体把握.     

Influence of the word length and input power on nonlinear crosstalk induced by hybrid optical amplifiers

In this paper, the influence of the word length (WL) of a pseudo-random bit sequence (PRBS) and the input laser power on nonlinear crosstalk induced by the different hybrid optical amplifiers (HOAs) has been examined. It is found that the crosstalk is strongly dependent on the WL and very sensitive to the relative powers of the input signals at 0.2 nm and 0.4 nm of the channel spacing. It is shown that the proposed hybrid Raman–EDFA induces lesser crosstalk as compared to other HOAs. The performance of Raman–EDFA HOA is also investigated for 16 × 10 Gbps dense wavelength division multiplexed (DWDM) system at 0.2 nm of channel spacing.     

Design of Fully Balanced Analog Systems Based on Ordinary and/or Modified Single-Ended Opamps

The system architectures, which allow a high performance fully balanced (FB) system based on ordinary/modified single-ended opamps to be implemented, are investigated and the basic and general requirements are formulated. Two new methods of an FB analog system design, which contribute towards achieving both a high performance IC system implementation and a great reduction of the design time are presented. It is shown that a single-ended system based on any type of opamp (rail-to-rail, constant g _m , etc.), realized in any technology (CMOS, bipolar, BiCMOS, GaAs), can be easily and effectively converted to its FB counterpart in a very practical way. Using the proposed rules, any FB system implementation with opamps (data converter, modulator, filter, etc.) requires only a single-ended system version design and the drawbacks related to a conventional FB system design are avoided. The principles of the design are pointed out and they are verified by experimental results.     

基于下视图像的打击效果评估系统研究

研究了打击效果评估的基本概念及该技术在国外的发展与应用情况,提出了基于下视图像的毁伤特征提取方法与典型目标毁伤评估准则。从物理级、功能级和系统级三个层次对打击效果评估进行了描述,提出了基于变化检测的物理级毁伤效果评估方法、基于自动目标识别的物理级毁伤评估方法和基于专家知识库的功能级毁伤评估方法,开发实现了基于下视图像的典型目标打击效果评估系统。仿真结果表明,所提出打击效果评估方法是有效的。     

任务规划系统验证方法研究

基于对国内外任务规划系统的研究,从研究任务规划系统的划分入手,分析各种任务规划系统的工作内容和工作环境,从运行环境、工作方式、规划内容和部署方式等四种方式对任务规划系统进行了划分。最后从工程研制角度和使用角度,提出了任务规划系统的验证方法和验证流程。指出任务规划系统的验证可划分为硬件验证、软件测试和系统级试验,可通过设计各种想定对各验证项目进行验证。     

基于RF MEMS开关的新型双频带功率放大器

RF MEMS开关具有低损耗、低功耗、尺寸小和易于集成等优点而被广泛应用于各种可重构射频电路及系统中。通过分析比较电容并联式和串联式RF MEMS开关两种电路结构的射频性能,设计了一种基于RF MEMS开关的新型功率放大器,使用RF MEMS开关控制匹配网络来实现双工作频带的转换。结果表明,设计的功率放大器在2.35GHz和1.25GHz两个工作频带下,功率附加效率(PAE)和输出功率(Pout)可分别达到72%、67%及40.8、42.7dBm。该功率放大器具有较高的功率附加效率和输出功率,适用于多频带的射频系统,对RF MEMS器件在可重构系统中的应用具有一定参考价值。     

Research and design of a novel current mode charge pump

To meet the demands for a number of LEDs, a novel charge pump circuit with current mode control is proposed. Regulation is achieved by operating the current mirrors and the output current of the operational transcon ductance amplifier. In the steady state, the input current from power voltage retains constant, so reducing the noise induced on the input voltage source and improving the output voltage ripple. The charge pump small-signal model is used to describe the device's dynamic behavior and stability. Analytical predictions were verified by Hspice sim ulation and testing. Load driving is up to 800 mA with a power voltage of 3.6 V, and the output voltage ripple is less than 45 mV. The output response time is less than 8 μs, and the load current jumps from 400 to 800 mA.     

美军作战实验室发展现状及其启示

对美军联合作战实验室,及其下辖的陆军作战实验室、海军战斗中心、空军作战实验室、海军陆战队战斗实验室、空间作战实验室等的体系结构、发展现状及其近期进行的作战实验情况进行了概述,对作战实验所采用的主要技术手段,特别是ACTD进行了深入分析.通过借鉴美军作战实验室在武器装备发展和战斗力提高的巨大作用和影响,提出了构建完善的作战实验室体系,创新发展武器装备手段;重视仿真模拟手段,提高部队技术、战术水平的观点,立足防空作战实验室的自身定位,提出了创新联合防空新战法的目标.     

High-Speed High-Precision CMOS Current Conveyor

In this paper a new class-AB CMOS second generation current conveyor (CCII) based on a novel high-performance voltage follower topology is proposed. Post-layout simulation results from a 0.8 m design supplied at 3.3 V show very low resistance at node X (<50 ), high frequency operation (100 MHz), high precision in the voltage and current transference and reduced offset. As application examples, a V-I converter and a current feedback operational amplifier (CFOA) have been implemented. The latter presents slew-rate levels higher than ±100 V/s.     

A review of recent progress in holmium-doped silica fibre sources

In this paper we present a review of holmium-doped silica fibre based sources. We discuss recent demonstrations of an efficient cladding-pumped fibre geometry and the impact it has made on the power scaling of these sources. We discuss the wavelength region that is addressable by holmium-doped silica based devices and highlight the advantage over thulium-doped fibres in terms of atmospheric transmission. Finally we review the development and current status of the pulsed and CW operation of holmium fibre sources and discuss the future development potential of sources in the ns-fs pulse-width range.