基于空间耦合注入的EMP防护器件评估

针对电磁脉冲防护器件的防护效果测试方法,国内外现有测试标准中均是通过传导注入(直接注入或耦合注入)标准试验波形的方式,对防护器件性能进行评估测试.文章对比介绍了现有的测试方法及注入的脉冲波形参数,并从防护器件的实际应用场景出发,提出了一种利用实验室EMP(强电磁脉冲)辐照试验系统评估防护器件的防护效果的新方法.通过高空核电磁脉冲(HEMP)试验模拟装置在实验室内获得要求的均匀场分布,使用射频天线模拟系统前端耦合路径,产生GJB 151 B-2013要求的瞬态脉冲电流,通过对比耦合路径中串入防护器件前后的电压值评估其防护性能.该方法注入的脉冲波形具有较高的逼真度,可为武器装备的电磁脉冲防护设计提供有效的参考,避免出现"过设计"或"欠设计".两型防护样机的测试验证表明:空间耦合注入法得到的测试结果一致性较好,具有可行性.     

移动装备的电磁脉冲防护模块测试方法研究

介绍美军标MIL-STD-188-125-2军用移动电磁脉冲防护标准,分析标准规定的脉冲电流注入的测试要求。研究电磁脉冲防护模块的测试方法,并进行探索性的加载试验。结果表明,防护模块响应时间和限压比等参数符合设计指标,加载试验中防护模块保护了后端的负载,起到了防护的作用。     

信号线滤波器的电磁脉冲防护性能试验

为检验信号线滤波器对电磁脉冲在信号线上产生的传导干扰的抑制能力,针对不同型号的信号线滤波器进行脉冲电流注入(PCI)测试,注入电流峰值分为100 A、200 A和500 A三个等级.测量滤波器输出线残余电流,计算相应电流抑制比,并对滤波器输出线和滤波器外壳之间的绝缘电阻进行测量.试验结果表明,100～500 A之间的注入电流就可以使信号线滤波器输出线与滤波器壳体发生绝缘击穿.因此,试验过程中需要关注滤波器的非线性效应,每个等级注入试验后要及时检查滤波器功能是否正常.     

屏蔽室线缆滤波器雷电防护性能评估

加装滤波器是抑制屏蔽室电源线和信号线传导干扰的常见方式之一。为研究屏蔽室线缆滤波器雷电冲击下的防护性能,分别进行了六种型号信号线滤波器和五种型号电源线滤波器不同等级的雷电脉冲注入试验。通过监测滤波器输出端残余电流,并测量滤波器输出线和壳体之间的绝缘电阻来评估其防护效果。试验表明:信号线和电源线滤波器雷电脉冲注入时的残余电流多数大于同等级核电磁脉冲注入时的残余电流;电源线滤波器在雷电脉冲注入时的残余电流峰值可达上千安培,传统线缆滤波器对雷电脉冲和核电磁脉冲传导干扰的防护能力有限;试验中应重点关注滤波器的非线性效应,特别是高等级电流注入时残余电流低于限定值而低等级电流注入时残余电流超出限定值的情况。     

基于阻抗失配的快沿方波脉冲防护研究

针对快沿方波电磁脉冲的防护问题,分析了不同半导体防护器件的阻抗变化对电磁脉冲的响应时间、端口传输功率的影响,得出了阻抗失配具有良好的方波电磁脉冲抑制作用和响应速度快的特性;为提高功率容量,采用了微带滤波器,通过1/4波长原理,仿真、设计、制作了1/4 波长微带带通滤波器,频率范围3.2 ~6.2 GHz,插入损耗臆1.8 dB,阻抗为50 W,在1 GHz 处的带外抑制为30 dB;利用高频噪声发生器(INS-4040)产生的快沿方波脉冲对其进行测试,结果表明此微带带通滤波器对快沿方波脉冲具有很好的抑制作用,同时具有亚纳秒的响应时间。     

强激光打靶产生电磁脉冲特性与传导防护研究

为了降低电磁脉冲的场强大小,加强强激光打靶产生电磁脉冲的传导防护性能,提出了强激光打靶产生电磁脉冲特性与传导防护研究。由于强激光打靶产生电磁脉冲对各种电子设备和电气设备都会造成一定威胁,采用双指数函数,分析了强激光打靶产生电磁脉冲的时域波形频谱,完成了强激光打靶产生电磁脉冲的特性研究;为了消除强激光打靶产生的电磁脉冲波,分析了电磁脉冲理想滤波器的衰减特性,并利用电磁脉冲滤波器的衰减计算公式,设计了电磁脉冲滤波器;利用电磁脉冲滤波器的衰减特性,在强激光打靶产生电磁脉冲过程中安装了屏蔽体,通过计算强激光打靶产生电磁脉冲的传导防护效能,实现了强激光打靶产生电磁脉冲的传导防护。仿真结果显示,提出的传导防护方法与其他两种方法相比,电磁脉冲的传导防护性能更好。     

大电流作用下电缆转移阻抗非线性特性研究

为了研究屏蔽电缆受外界电磁脉冲作用可能产生的非线性效应,提出了屏蔽电缆表面转移阻抗的大电流注入测试方法.建立了大电流注入测试系统,通过注入测试方法获得了不同电流等级下电缆转移阻抗曲线,对比了两类屏蔽多芯电缆的芯线电磁脉冲耦合情况.实验表明:加入一层铁磁性屏蔽层的多芯电缆在注入电流峰值超过2kA时,芯线耦合电压会呈现非线性效应.并分析了该现象产生的原因.     

强电磁脉冲对计算机电缆的注入毁伤效应研究

为研究强电磁脉冲对计算机系统电缆端口的毁伤效应,通过电磁脉冲耦合注入方式分别对未加装防护电路和加装防护电路的VGA视频端口进行电磁脉冲毁伤试验,详细记录了VGA视频端口的测试结果。通过试验数据表明,计算机电缆接口的毁伤阈值相对较低,而增加专用的电磁脉冲接口抑制电路后,计算机视频电缆接口的抗强电磁脉冲打击能力明显提高。     

基于脉冲电流注入的差分芯片敏感度研究

采用脉冲电流注入(PCI)技术,对差分信号接收芯片(DS26C32ATM)的敏感阈值进行研究。试验结果表明,随着脉冲源电压的增大,传输线上的注入电流增大,差分信号接收芯片接口电路受到电磁脉冲干扰,发生损伤。对损伤芯片进行失效机理分析,定位故障。针对失效机理分析结果,对差分信号接收芯片进行加固防护研究。试验结果为后续差分芯片的抗电磁脉冲干扰的性能试验提供可靠依据。     

HEMP 传导型防护模块测试系统的设计与实现

依据GJB 3622-1999 标准,针对高空核电磁脉冲(HEMP)传导型防护模块的测试需求,设计了一套线-地脉冲电流耦合注入测试系统,完成了高空核电磁脉冲的产生、测量系统的搭建和射频EMP 保护器的测试。该系统脉冲上升沿tr ≤10 ns,脉冲半宽度500 ns≤ thw ≤550 ns,设计指标完全符合GJB 3622-1999 标准的要求。为测试方便,设计脉冲发生器中的高压源在0 ~50 kV 范围内人工调节,并实现了油绝缘火花隙开关遥控放电。测试系统采用电流探头(罗氏线圈)、电压探头、数字存储示波器等设备进行电流和电压的采集,利用所测数据计算出被测防护模块的电流抑制比(SEI),从而完成对传导型防护模块的性能测试以及毁伤阈值测试。本测试系统性能稳定,可靠性高,测试数据准确可靠,目前已经在工程实践中得到了广泛应用,取得了很好的效果。     

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.     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.