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  • 基于FPGA的光纤光栅解调系统的研究

     波长信号的解调是实现光纤光栅传感网络的关键,基于现有的光纤光栅传感器解调方法,提出一种基于FPGA的双匹配光纤光栅解调方法,此系统是一种高速率、高精度、低成本的解调系统,并且通过引入双匹配光栅有效地克服了双值问题同时扩大了检测范围。分析了光纤光栅的测温原理并给出了该方案软硬件设计,综合考虑系统的解调精度和FPGA的处理速度给出了基于拉格朗日的曲线拟合算法。 Abstract:  Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network, based on several existing methods of fiber grating sensor demodulation inadequate, a two-match fiber grating demodulation method was presented. This system is a high-speed, high precision, low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA,this paper gives the curve fitting algorithm based on Lagrange.

    标签: FPGA 光纤光栅 解调系统

    上传时间: 2014-07-24

    上传用户:caiguoqing

  • MAX7060的ASK_FSK的ISM射频发射机

    Abstract: This application note illustrates the flexibility of the MAX7060 ASK/FSK transmitter. While the currently available evaluationkit (EV kit) has been optimized for the device's use in a specific frequency band (i.e., 288MHz to 390MHz), this document addresseshow the EV kit circuitry can be modified for improved operation at 433.92MHz, a frequency commonly used in Europe. Twoalternative match and filter configurations are presented: one for optimizing drain efficiency, the other for achieving higher transmitpower. Features and capabilities of earlier Maxim industrial, scientific, and medical radio-frequency (ISM-RF) transmitters areprovided, allowing comparison of the MAX7060 to its predecessors. several design guidelines and cautions for using the MAX7060are discussed.

    标签: ASK_FSK 7060 MAX ISM

    上传时间: 2013-11-14

    上传用户:swaylong

  • 智能天线技术在基站中的应用

    为了能够满足基站易于选址、优质快速的建站要求和易维护、低成本、高可靠的运行要求,本文对以方舱来实现一体化结构基站做出一番探讨。从系统设计的观点阐述了移动通信高性能基站天线设计的几个关键问题,介绍了智能天线技术在基站中的应用,并且用HFSS软件仿真了一种新型的对称阵子天线,该天线驻波比小于2的带宽可以达到60%,具有良好的宽频带特性。 Abstract:  In order to meet the station construction requirement of easy site selection and fast base station, and meet the operational requirement of easy maintenance, low cost and high reliability, this paper discussed the unified architecture base station using shelter. several key problems of high performance mobile communication base station antenna were illustrated from the view of system design, the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS, the VSWR of the antenna is less than 2, and the bandwidth was reach to 60%. So it has good broadband properties.

    标签: 智能天线 基站 中的应用

    上传时间: 2013-11-20

    上传用户:linlin

  • 轨道交通系统中列车定位技术

       阐述了轨道交通列车定位技术。介绍了在轨道交通系统中列车定位技术的功能,国内外轨道交通中主要采用的列车定位方法,重点论述了几种主要定位技术,并从定位精度、闭塞制式、维护投资成本、抗干扰等方面进行分析比较。提出目前轨道交通定位技术应综合运用,取长补短,多种方法相互融合,才能满足轨道交通中对安全可靠性的要求。 Abstract:  Rail train positioning technology is described. The paper introduces the funetions of the train positioning technology in the rail transit system, the main methods of train positioning do mestic and international rail, and focuses on several key methods, analyzes and compares from the positioning accuracy, block system, maintenance and investment cost, interference and so on, suggested that the current rail positioning technology should be integrated use of positioning method of meriging, learn from each other, to meet the reliability requirements of rail safety.

    标签: 轨道交通 列车 定位技术

    上传时间: 2013-11-25

    上传用户:franktu

  • 采用TÜV认证的FPGA开发功能安全系统

    This white paper discusses how market trends, the need for increased productivity, and new legislation have accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to market. This allows FPGA users to design their own customized safety controllers and provides a significant competitive advantage over traditional microcontroller or ASIC-based designs. Introduction The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas around machines such as fast-moving robots, and distributed control systems in process automation equipment such as those used in petrochemical plants. The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was developed in the mid-1980s and has been revised several times to cover the technical advances in various industries. In addition, derivative standards have been developed for specific markets and applications that prescribe the particular requirements on functional safety systems in these industry applications. Example applications include process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC 62304), automotive (ISO 26262), power generation, distribution, and transportation. 图Figure 1. Local Safety System

    标签: FPGA 安全系统

    上传时间: 2013-11-14

    上传用户:zoudejile

  • 基于FPGA+DSP模式的智能相机设计

    针对嵌入式机器视觉系统向独立化、智能化发展的要求,介绍了一种嵌入式视觉系统--智能相机。基于对智能相机体系结构、组成模块和图像采集、传输和处理技术的分析,对国内外的几款智能相机进行比较。综合技术发展现状,提出基于FPGA+DSP模式的硬件平台,并提出智能相机的发展方向。分析结果表明,该系统设计可以实现脱离PC运行,完成图像获取与分析,并作出相应输出。 Abstract:  This paper introduced an embedded vision system-intelligent camera ,which was for embedded machine vision systems to an independent and intelligent development requirements. Intelligent camera architecture, component modules and image acquisition, transmission and processing technology were analyzed. After comparing integrated technology development of several intelligent cameras at home and abroad, the paper proposed the hardware platform based on FPGA+DSP models and made clear direction of development of intelligent cameras. On the analysis of the design, the results indicate that the system can run from the PC independently to complete the image acquisition and analysis and give a corresponding output.

    标签: FPGA DSP 模式 智能相机

    上传时间: 2013-11-14

    上传用户:无聊来刷下

  • 基于FPGA的光纤光栅解调系统的研究

     波长信号的解调是实现光纤光栅传感网络的关键,基于现有的光纤光栅传感器解调方法,提出一种基于FPGA的双匹配光纤光栅解调方法,此系统是一种高速率、高精度、低成本的解调系统,并且通过引入双匹配光栅有效地克服了双值问题同时扩大了检测范围。分析了光纤光栅的测温原理并给出了该方案软硬件设计,综合考虑系统的解调精度和FPGA的处理速度给出了基于拉格朗日的曲线拟合算法。 Abstract:  Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network, based on several existing methods of fiber grating sensor demodulation inadequate, a two-match fiber grating demodulation method was presented. This system is a high-speed, high precision, low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA,this paper gives the curve fitting algorithm based on Lagrange.

    标签: FPGA 光纤光栅 解调系统

    上传时间: 2013-10-10

    上传用户:zxc23456789

  • 开关电源EMI设计(英文版)

    Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.

    标签: EMI 开关电源 英文

    上传时间: 2013-11-16

    上传用户:萍水相逢

  • This algorithm was developed by Professor Ronald L. Rivest of MIT and can be found presented in seve

    This algorithm was developed by Professor Ronald L. Rivest of MIT and can be found presented in several languages. What I provide to you here is a C++ derivative of the original C implementation of Professor Rivets. The library code itself is platform-independant and has been tested in Redhat Linux. I ve included the sample code and makefile that I used for the Linux test. The demo, however, was written with Visual C++ 6 on a Windows 2000 platform.

    标签: L. Professor algorithm developed

    上传时间: 2014-12-21

    上传用户:gonuiln

  • BonkEnc is a CD ripper and audio encoder for various formats. It can produce MP3, Ogg Vorbis, BONK,

    BonkEnc is a CD ripper and audio encoder for various formats. It can produce MP3, Ogg Vorbis, BONK, AAC and VQF files. BonkEnc supports freedb (CDDB), CD-Text and ID3 tags and is available is several languages

    标签: BonkEnc encoder formats produce

    上传时间: 2015-01-14

    上传用户:ywqaxiwang