關于FPGA流水線設計的論文\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
上傳時間： 2013-09-03
上傳用戶：wl9454
在國內Protel軟件一直大受歡迎，從DOS時代的Protel3.3(Autotrax 1.61)到現在具有EDA Client/Server （客戶/服務器）即C/S“框架”體系結構的Protel98，它始終是PCB設計和制造領域的大眾化工具軟件，成為電子設計工作者們的首選。 在規范化的設計管理中，設計文件圖樣必須遵守相應的國家標準，如《電子產品圖樣繪制規則》、《設計文件管理制圖》和《印制板制圖》等，而由于Protel軟件都是英文版，因此無法直接打印出符合國家標準的圖紙，要將圖紙規范化常用的方式是套打，即先將符合國家標準的表和漢字等打在紙上，再將該紙放入打印機，用Protel軟件將印制板圖打印其上，形成符合標準的文件，但這種做法效率很低，而且圖形常會打偏，有時甚至會打反，經筆者試驗，找到了一種簡便的方法，使印制板圖轉換為AUTOCAD格式，再在AUTOCAD里一次性打印出符合標準的圖紙。
上傳時間： 2013-10-12
上傳用戶：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..
上傳時間： 2013-11-21
上傳用戶：lchjng
分析了調幅信號和載波信號之間的相位差與調制信號的極性的對應關系,得出了相敏檢波電路輸出電壓的極性與調制信號的極性有對應關系的結論。為了驗證相敏檢波電路的這一特性,給出3 個電路方案,分別選用理想元件和實際元件,采用Multisim 對其進行仿真實驗,直觀形象地演示了相敏檢波電路的鑒相特性,是傳統的實際操作實驗所不可比擬的。關鍵詞:相敏檢波;鑒相特性;Multisim;電路仿真 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
上傳時間： 2013-11-23
上傳用戶：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.
上傳時間： 2014-12-23
上傳用戶：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.
上傳時間： 2014-12-24
上傳用戶：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.
上傳時間： 2013-12-20
上傳用戶：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.
上傳時間： 2014-03-25
上傳用戶：yyyyyyyyyy
在國內Protel軟件一直大受歡迎，從DOS時代的Protel3.3(Autotrax 1.61)到現在具有EDA Client/Server （客戶/服務器）即C/S“框架”體系結構的Protel98，它始終是PCB設計和制造領域的大眾化工具軟件，成為電子設計工作者們的首選。 在規范化的設計管理中，設計文件圖樣必須遵守相應的國家標準，如《電子產品圖樣繪制規則》、《設計文件管理制圖》和《印制板制圖》等，而由于Protel軟件都是英文版，因此無法直接打印出符合國家標準的圖紙，要將圖紙規范化常用的方式是套打，即先將符合國家標準的表和漢字等打在紙上，再將該紙放入打印機，用Protel軟件將印制板圖打印其上，形成符合標準的文件，但這種做法效率很低，而且圖形常會打偏，有時甚至會打反，經筆者試驗，找到了一種簡便的方法，使印制板圖轉換為AUTOCAD格式，再在AUTOCAD里一次性打印出符合標準的圖紙。
上傳時間： 2013-11-01
上傳用戶：杏簾在望
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.
上傳時間： 2013-10-18
上傳用戶：masochism
