平台导引头隔离度寄生回路特性分析

平台导引头隔离度的存在不仅降低了导引头跟踪精度,其引起的隔离度寄生回路对导弹制导系统存在严重的影响。通过对平台导引头隔离度产生机理进行分析,分别建立了弹簧力矩和阻尼力矩引起的隔离度模型,在此模型的基础上利用劳斯判据分析了隔离度寄生回路稳定边界,并研究了寄生回路对制导系统有效时间常数和有效比例导引系数的影响。结果表明:为了保证隔离度寄生回路的稳定,需要限制制导控制系统主要参数的取值范围;在寄生回路的作用下制导系统有效时间常数和有效比例导引系数与原设计值发生偏差,需要重点关注。所得结论可以为导弹制导控制系统初步设计以及导引头总体指标确定提供理论参考。     

基于STUKF的激光平台导引头干扰力矩在线补偿方法研究

隔离度会降低导引头输出信息的精度,增加导弹的脱靶量。针对激光平台导引头的隔离度问题,首先建立了考虑隔离度寄生回路的制导系统模型,经分析确定干扰力矩为引发隔离度的主要原因,并提出采用滤波算法对其进行估计补偿的方案。之后依据平台导引头的基本结构与干扰力矩的产生机理建立了用于在线辨识隔离度的非线性滤波模型,采用强跟踪无迹卡尔曼滤波算法（STUKF）补偿建模误差,解决了干扰力矩难以精确建模的问题,以对其进行在线辨识与前馈补偿。最后对所提方法进行了数学仿真与半实物仿真实验论证,实验结果表明:所提方法可增强导引头光轴对弹目视线角速度的跟踪能力,改善导引头输出制导信息的品质,并有效地抑制隔离度,达到提升系统制导精度的目的。     

TD-SCDMA系统二级合路的隔离度要求

目前,在大部分热点公共服务场所都采用了集约化建设,将2G和3G将近十个系统都统一纳入POI平台,各系统端口间的隔离度达到80~90dB,同时采用收发分缆的方式,进一步提高收发间的隔离度,可以满足杂散、阻塞和互调干扰的要求。但是鉴于TD-SCDMA为时分双工系统,通常采用二级合路的方式将其接入上行合路平台,这就要求对TD-SCDMA系统的合路指标做进一步分析。特别对1880~1920 MHz频段,由于接近3G/FDD的1920~1960 MHz频段,更需要采取进一步措施以保证满足隔离度的指标要求。     

新建铁塔系统平台方案研究

首先介绍铁塔公司合理分配平台的重要性,然后阐述三大运营商的建设策略,并从隔离度角度,分析三大运营商的覆盖需求;从受限频段角度说明三大运营商的站间距规划,最后重点说明分场景各系统的平台分析,并给出铁塔公司网络规划的建议.     

WLAN与异系统干扰及隔离度的研究

结合了干扰隔离度的工程要求对系统间干扰进行分析,通过建立系统间干扰隔离度的模型,重点研究了2.4 GHz频段上WLAN系统与异系统间的隔离度,最后采用MCL算法得到系统间的天线隔离度要求及天线间空间隔离度的指标。     

LTE系统干扰隔离度计算及干扰案例分析

本文首先介绍了LTE干扰分类和干扰分析方法,然后详细给出了LTE干扰隔离度计算流程和计算方法,以及根据干扰隔离度计算隔离距离的方法,并以LTE 800M系统为例,给出其干扰隔离度和隔离距离计算过程和结果.最后通过两个LTE干扰案例,示例干扰分析过程和解决方法.     

TD-LTE系统干扰分析

文章对TD-LTE的系统内外干扰的机理进行了系统分析,并结合标准中的设备性能最低要求计算出典型情况下系统间隔离度要求,以及隔离度的实现方法。     

WCDMA系统与其他无线系统共存时隔离度分析

首先分析了WCDMA系统与其他无线系统共存时所需的隔离度,然后给出了满足一定灵敏度损失标准时,系统所需隔离度的计算方法,最后详细介绍了WCDMA系统与GSM系统共存时,系统之间所需隔离度的计算。     

微波/毫米波天线在复合布阵中的隔离度研究

通过简化模型以及建立仿真模型来分析微波/毫米波天线在复合阵列中的隔离度情况.首先分析了同频率阵元之间的隔离度问题,对单独两个微波圆锥脊喇叭的两种间距和单独两个毫米波角锥喇叭的两种间距进行了S参数分析.然后又对不同频率阵元之间的隔离度问题进行了分析.结论对微波/毫米波复合阵列的设计和性能分析具有很好的参考价值.     

干扰隔离度的计算及其对有效利用静止卫星轨道.频谱的应用

作为一种新的解析手段的干扰隔离度概念是解决任意不均匀参数的卫星轨道/频谱拥塞问题的一种有效途径。本文首先论述广义干扰隔离度方程的建立和有效隔离度(A I.)及所需隔离度(R.I.)的基本概念,进而讨论其计算方法。最后列举有关数值计算结果及一些理解性示例阐明如何借助此隔离度概念进行规划协调以降低干扰及增加轨道/频谱利用能力。本文所介绍的方法对协调估计、频谱及轨道间隔的分配以及对国内和国际应用的不均匀参数卫星系统及网路的性能预测和设计均相当有用。     

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.