基于帧格式的调频遥测信号检测方法分析

针对航天器测控特点,低信噪比信号检测是实现航天测控系统目标快速捕获的关键技术。为了解决调频遥测信号低信噪比检测难题,介绍了采用正交矢量瞬时测频方法的调频遥测信号解调方法,分析了调频遥测信号帧格式,在此基础上提出了基于帧格式的调频遥测信号匹配滤波检测法。仿真结果表明所提方法能实现在低信噪比条件下调频遥测信号的高概率检测。     

基于FPGA的PCM-FM遥测中频接收机设计与实现

本文设计实现了一款基于FPGA的PCM-FM遥测中频接收机,在FPGA中实现遥测信号解调、位同步、帧同步等功能,系统码速率、帧长、帧同步码可灵活设置。接收机硬件结构简单,主要包括FPGA、ADC、电源转换芯片、USB接口芯片等常用器件,可单板实现,达到低成本、小型化设计要求。性能测试表明,中频接收机满足设计指标要求,目前该接收机已服务于多个项目。本文网络版地址：http：//www.eepw.com. cn/article/274756.htm     

基于VBScript的遥测数据处理技术研究

飞行器的遥测数据帧格式随型号、批次而不同,给遥测数据处理带来很大不便。利用Active X Scripting技术能实现VBScript引擎嵌入到遥测处理程序中,使得遥测处理程序在不修改程序的情况下能够通过VBScript脚本灵活处理多变的数据帧格式。经应用证明,该技术具有配置灵活、可扩展性强等特点,能够满足不同格式遥测数据解析的需要。     

基于数据库的遥测数据传输系统的设计

针对原有遥测数据传输模式的缺陷,构建了新型统一的数据模型。系统采用数据库技术来存储遥测数据处理全过程所需配置信息,从遥测数据库中读取系统所需信息,根据遥测帧格式信息,对接收到的遥测原始数据进行验证并组帧;随后挑点解算需要处理的遥测参数。依据该数据库模型来重新设计遥测数据传输系统的软件架构,通过优化系统架构、减少了软件维护工作量,使软件系统具有较强的通用性和扩展性。系统在新型火箭飞行测控任务中得到了很好的应用。     

基于USB和FPGA的多功能等效器设计

针对航天遥测设备在研制和地面模拟测试中需要有设备模拟遥测外系统的各种控制和测量参数,设计并实现了一种以FPGA、USB、高速DAC、DS26C31、高速光耦AQY210为核心,结构简单、控制灵活、信号质量高的多功能等效器。该等效器实现了上位机与等效器主控模块FPGA的通信接口使用了FT245RL;多路不同参数的直流信号;正弦信号;基于AQY210的时间指令脉冲信号;应用DS26C31实现了特定帧结构的异步串行通信数据。     

基于微程序设计实现可编程PCM遥测

通过对可编程他PCM 遥测多路信号帧格式、合路和分路方式的分析,提出了将微程序设计用于可编程 PCM 遥测的方法,给出了采用微程序实现可编程合路与分路的方案。微程序设计法用于可编程 PCM 遥测不仅可以使系统设计灵活,实现简化,而且大大节省硬件,提高可靠性。实验证明:微程序设计应用于可编程 PCM 遥测切实可行。     

遥测参数的实时判别

遥测参数代表了火箭或导弹等飞行器的实时状态,所以在任务中实现参数的实时判别已经是必须而紧迫的任务。详细讲述了遥测参数的子帧、副帧和特殊帧的结构形式,针对参数的各种结构形式提出了线性增长判断、越界判断和比特位判断等几种实时判决方法,在实际工程中得到了较好的效果。结合工程实践讲述了遥测参数实时判断软件的结构和实现方法,并介绍了工程软件开发过程中的一些经验和技巧。     

遥测PCM数据加密技术研究

遥测数据中包含飞机及武器的大量重要数据信息,是现代电子战中第三方的主要截获目标,因此遥测数据的加密需求变得更加迫切。针对这一需求,在分析加密算法的基础上,提出了遥测数据加密方案。通过分析PCM帧格式,并合理配置密码字在PCM帧中的位置,在现有系统中通过增加加、解密相关设备,完成遥测数据的加、解密过程。配合合理的密钥管理机制,实现了遥测数据的加密传输。经实践证明,该技术能够满足飞行试验遥测数据传输的基本需求。     

用2716芯片制作的音乐彩色喷泉控制器

<正> 本文介绍的音乐彩色喷泉控制器不是用微机或单片机制作而成的,而是用2716型EPROM芯片制作的。它用音乐信号和程控信号去控制EPROM的地址,再用其相应地址下的输出数码去控制彩灯和水泵,这样,通过改变EPROM芯片的数码内容,就能方便地改变喷泉控制器的组数。而当水泵和彩灯的总组数超过EPROM芯片的数码位数时,也只需再并接一片EPROM芯片。它具有结构简单、功能齐全、操作方便等特点,非常适于个人、小型企业和喷泉用户自动制作。     

基于DSP平台的AVS实时编码系统设计

针对DM642的特点优化了AVS编码器,实现了Dl格式视频25 f/s(帧/秒)的实时压缩和网络传输.同时.编码器符合TMS320DSP算法标准XDAIS具有很好的移植性.     

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.     

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.