关于FPGA流水线设计的论文\r\nThis work investigates the use of very deep pipelines for\r\nimplementing circuits in FPGAs, where each pipeline\r\nstage is limited to a single FPGA logic ELEMENT (LE). The\r\narchitecture and VHDL design of a parameterized integer\r\na
上传时间： 2013-09-03
上传用户：wl9454
在国内Protel软件一直大受欢迎，从DOS时代的Protel3.3(Autotrax 1.61)到现在具有EDA Client/Server （客户/服务器）即C/S“框架”体系结构的Protel98，它始终是PCB设计和制造领域的大众化工具软件，成为电子设计工作者们的首选。 在规范化的设计管理中，设计文件图样必须遵守相应的国家标准，如《电子产品图样绘制规则》、《设计文件管理制图》和《印制板制图》等，而由于Protel软件都是英文版，因此无法直接打印出符合国家标准的图纸，要将图纸规范化常用的方式是套打，即先将符合国家标准的表和汉字等打在纸上，再将该纸放入打印机，用Protel软件将印制板图打印其上，形成符合标准的文件，但这种做法效率很低，而且图形常会打偏，有时甚至会打反，经笔者试验，找到了一种简便的方法，使印制板图转换为AUTOCAD格式，再在AUTOCAD里一次性打印出符合标准的图纸。
上传时间： 2013-10-12
上传用户：Wwill
This application note describes a Linear Technology "Half-Flash" A/D converter, the LTC1099, being connected to a 256 ELEMENT line scan photodiode array. This technology adapts itself to handheld (i.e., low power) bar code readers, as well as high resolution automated machine inspection applications..
上传时间： 2013-11-21
上传用户：lchjng
分析了调幅信号和载波信号之间的相位差与调制信号的极性的对应关系,得出了相敏检波电路输出电压的极性与调制信号的极性有对应关系的结论。为了验证相敏检波电路的这一特性,给出3 个电路方案,分别选用理想元件和实际元件,采用Multisim 对其进行仿真实验,直观形象地演示了相敏检波电路的鉴相特性,是传统的实际操作实验所不可比拟的。关键词:相敏检波;鉴相特性;Multisim;电路仿真 Abstract : The corresponding relation between modulation signal polarity and difference phases of amplitudemodulated signal and the carrier signal ,the polarity of phase2sensitive detecting circuit output voltage and the polarity of modulation signal are correspondent . In order to verify this characteristic ,three elect ric circuit s plans are produced ,idea ELEMENT s and actual ELEMENT s are selected respectively. Using Multisim to carry on a simulation experiment ,and then demonst rating the phase detecting characteristic of the phase sensitive circuit vividly and directly. Which is t raditional practical experience cannot be com pared.Keywords :phase sensitive detection ;phase2detecting characteristic ;Multisim;circuit simulation
上传时间： 2013-11-23
上传用户：guanhuihong
Radio Frequency Integrated Circuit Design I enjoyed reading this book for a number of reasons. One reason is that itaddresses high-speed analog design in the context of microwave issues. This isan advanced-level book, which should follow courses in basic circuits andtransmission lines. Most analog integrated circuit designers in the past workedon applications at low enough frequency that microwave issues did not arise.As a consequence, they were adept at lumped parameter circuits and often notcomfortable with circuits where waves travel in space. However, in order todesign radio frequency (RF) communications integrated circuits (IC) in thegigahertz range, one must deal with transmission lines at chip interfaces andwhere interconnections on chip are far apart. Also, impedance matching isaddressed, which is a topic that arises most often in microwave circuits. In mycareer, there has been a gap in comprehension between analog low-frequencydesigners and microwave designers. Often, similar issues were dealt with in twodifferent languages. Although this book is more firmly based in lumped-ELEMENTanalog circuit design, it is nice to see that microwave knowledge is brought inwhere necessary.Too many analog circuit books in the past have concentrated first on thecircuit side rather than on basic theory behind their application in communications.The circuits usually used have evolved through experience, without asatisfying intellectual theme in describing them. Why a given circuit works bestcan be subtle, and often these circuits are chosen only through experience. Forthis reason, I am happy that the book begins first with topics that require anintellectual approach—noise, linearity and filtering, and technology issues. Iam particularly happy with how linearity is introduced (power series). In therest of the book it is then shown, with specific circuits and numerical examples,how linearity and noise issues arise.
上传时间： 2014-12-23
上传用户：han_zh
Calculation of the Differential Impedance of Tracks on FR4 substrates There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary ELEMENT field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
上传时间： 2014-12-23
上传用户：DE2542
Telecommunication, satellite links and set-top boxes allrequire tuning a high frequency oscillator. The actualtuning ELEMENT is a varactor diode, a 2-terminal device thatchanges capacitance as a function of reverse bias voltage.1 The oscillator is part of a frequency synthesizingloop, as detailed in Figure 1. A phase locked loop (PLL)compares a divided down representation of the oscillatorwith a frequency reference. The PLL’s output is levelshifted to provide the high voltage necessary to bias thevaractor, which closes a feedback loop by voltage tuningthe oscillator. This loop forces the voltage controlledoscillator (VCO) to operate at a frequency determined bythe frequency reference and the divider’s division ratio.
上传时间： 2013-12-20
上传用户：ABCDE
Single-Ended and Differential S-Parameters Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-ELEMENT models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-ELEMENTapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-ELEMENT techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上传时间： 2014-03-25
上传用户：yyyyyyyyyy
在国内Protel软件一直大受欢迎，从DOS时代的Protel3.3(Autotrax 1.61)到现在具有EDA Client/Server （客户/服务器）即C/S“框架”体系结构的Protel98，它始终是PCB设计和制造领域的大众化工具软件，成为电子设计工作者们的首选。 在规范化的设计管理中，设计文件图样必须遵守相应的国家标准，如《电子产品图样绘制规则》、《设计文件管理制图》和《印制板制图》等，而由于Protel软件都是英文版，因此无法直接打印出符合国家标准的图纸，要将图纸规范化常用的方式是套打，即先将符合国家标准的表和汉字等打在纸上，再将该纸放入打印机，用Protel软件将印制板图打印其上，形成符合标准的文件，但这种做法效率很低，而且图形常会打偏，有时甚至会打反，经笔者试验，找到了一种简便的方法，使印制板图转换为AUTOCAD格式，再在AUTOCAD里一次性打印出符合标准的图纸。
上传时间： 2013-11-01
上传用户：杏帘在望
Calculation of the Differential Impedance of Tracks on FR4 substrates There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary ELEMENT field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
上传时间： 2013-10-18
上传用户：masochism
