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Analysis-Numerical

  • 基于CPLD的QDPSK調制解調電路設計

    為了在CDMA系統中更好地應用QDPSK數字調制方式,在分析四相相對移相(QDPSK)信號調制解調原理的基礎上,設計了一種QDPSK調制解調電路,它包括串并轉換、差分編碼、四相載波產生和選相、相干解調、差分譯碼和并串轉換電路。在MAX+PLUSⅡ軟件平臺上,進行了編譯和波形仿真。綜合后下載到復雜可編程邏輯器件EPM7128SLC84-15中,測試結果表明,調制電路能正確選相,解調電路輸出數據與QDPSK調制輸入數據完全一致,達到了預期的設計要求。 Abstract:  In order to realize the better application of digital modulation mode QDPSK in the CDMA system, a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase,and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.

    標簽: QDPSK CPLD 調制解調 電路設計

    上傳時間: 2013-10-28

    上傳用戶:jyycc

  • 高速PCB基礎理論及內存仿真技術(經典推薦)

    第一部分 信號完整性知識基礎.................................................................................5第一章 高速數字電路概述.....................................................................................51.1 何為高速電路...............................................................................................51.2 高速帶來的問題及設計流程剖析...............................................................61.3 相關的一些基本概念...................................................................................8第二章 傳輸線理論...............................................................................................122.1 分布式系統和集總電路.............................................................................122.2 傳輸線的RLCG 模型和電報方程...............................................................132.3 傳輸線的特征阻抗.....................................................................................142.3.1 特性阻抗的本質.................................................................................142.3.2 特征阻抗相關計算.............................................................................152.3.3 特性阻抗對信號完整性的影響.........................................................172.4 傳輸線電報方程及推導.............................................................................182.5 趨膚效應和集束效應.................................................................................232.6 信號的反射.................................................................................................252.6.1 反射機理和電報方程.........................................................................252.6.2 反射導致信號的失真問題.................................................................302.6.2.1 過沖和下沖.....................................................................................302.6.2.2 振蕩:.............................................................................................312.6.3 反射的抑制和匹配.............................................................................342.6.3.1 串行匹配.........................................................................................352.6.3.1 并行匹配.........................................................................................362.6.3.3 差分線的匹配.................................................................................392.6.3.4 多負載的匹配.................................................................................41第三章 串擾的分析...............................................................................................423.1 串擾的基本概念.........................................................................................423.2 前向串擾和后向串擾.................................................................................433.3 后向串擾的反射.........................................................................................463.4 后向串擾的飽和.........................................................................................463.5 共模和差模電流對串擾的影響.................................................................483.6 連接器的串擾問題.....................................................................................513.7 串擾的具體計算.........................................................................................543.8 避免串擾的措施.........................................................................................57第四章 EMI 抑制....................................................................................................604.1 EMI/EMC 的基本概念..................................................................................604.2 EMI 的產生..................................................................................................614.2.1 電壓瞬變.............................................................................................614.2.2 信號的回流.........................................................................................624.2.3 共模和差摸EMI ..................................................................................634.3 EMI 的控制..................................................................................................654.3.1 屏蔽.....................................................................................................654.3.1.1 電場屏蔽.........................................................................................654.3.1.2 磁場屏蔽.........................................................................................674.3.1.3 電磁場屏蔽.....................................................................................674.3.1.4 電磁屏蔽體和屏蔽效率.................................................................684.3.2 濾波.....................................................................................................714.3.2.1 去耦電容.........................................................................................714.3.2.3 磁性元件.........................................................................................734.3.3 接地.....................................................................................................744.4 PCB 設計中的EMI.......................................................................................754.4.1 傳輸線RLC 參數和EMI ........................................................................764.4.2 疊層設計抑制EMI ..............................................................................774.4.3 電容和接地過孔對回流的作用.........................................................784.4.4 布局和走線規則.................................................................................79第五章 電源完整性理論基礎...............................................................................825.1 電源噪聲的起因及危害.............................................................................825.2 電源阻抗設計.............................................................................................855.3 同步開關噪聲分析.....................................................................................875.3.1 芯片內部開關噪聲.............................................................................885.3.2 芯片外部開關噪聲.............................................................................895.3.3 等效電感衡量SSN ..............................................................................905.4 旁路電容的特性和應用.............................................................................925.4.1 電容的頻率特性.................................................................................935.4.3 電容的介質和封裝影響.....................................................................955.4.3 電容并聯特性及反諧振.....................................................................955.4.4 如何選擇電容.....................................................................................975.4.5 電容的擺放及Layout ........................................................................99第六章 系統時序.................................................................................................1006.1 普通時序系統...........................................................................................1006.1.1 時序參數的確定...............................................................................1016.1.2 時序約束條件...................................................................................1063.2 高速設計的問題.......................................................................................2093.3 SPECCTRAQuest SI Expert 的組件.......................................................2103.3.1 SPECCTRAQuest Model Integrity .................................................2103.3.2 SPECCTRAQuest Floorplanner/Editor .........................................2153.3.3 Constraint Manager .......................................................................2163.3.4 SigXplorer Expert Topology Development Environment .......2233.3.5 SigNoise 仿真子系統......................................................................2253.3.6 EMControl .........................................................................................2303.3.7 SPECCTRA Expert 自動布線器.......................................................2303.4 高速設計的大致流程...............................................................................2303.4.1 拓撲結構的探索...............................................................................2313.4.2 空間解決方案的探索.......................................................................2313.4.3 使用拓撲模板驅動設計...................................................................2313.4.4 時序驅動布局...................................................................................2323.4.5 以約束條件驅動設計.......................................................................2323.4.6 設計后分析.......................................................................................233第四章 SPECCTRAQUEST SIGNAL EXPLORER 的進階運用..........................................2344.1 SPECCTRAQuest Signal Explorer 的功能包括:................................2344.2 圖形化的拓撲結構探索...........................................................................2344.3 全面的信號完整性(Signal Integrity)分析.......................................2344.4 完全兼容 IBIS 模型...............................................................................2344.5 PCB 設計前和設計的拓撲結構提取.......................................................2354.6 仿真設置顧問...........................................................................................2354.7 改變設計的管理.......................................................................................2354.8 關鍵技術特點...........................................................................................2364.8.1 拓撲結構探索...................................................................................2364.8.2 SigWave 波形顯示器........................................................................2364.8.3 集成化的在線分析(Integration and In-process Analysis) .236第五章 部分特殊的運用...............................................................................2375.1 Script 指令的使用..................................................................................2375.2 差分信號的仿真.......................................................................................2435.3 眼圖模式的使用.......................................................................................249第四部分:HYPERLYNX 仿真工具使用指南............................................................251第一章 使用LINESIM 進行前仿真.......................................................................2511.1 用LineSim 進行仿真工作的基本方法...................................................2511.2 處理信號完整性原理圖的具體問題.......................................................2591.3 在LineSim 中如何對傳輸線進行設置...................................................2601.4 在LineSim 中模擬IC 元件.....................................................................2631.5 在LineSim 中進行串擾仿真...................................................................268第二章 使用BOARDSIM 進行后仿真......................................................................2732.1 用BOARDSIM 進行后仿真工作的基本方法...................................................2732.2 BoardSim 的進一步介紹..........................................................................2922.3 BoardSim 中的串擾仿真..........................................................................309

    標簽: PCB 內存 仿真技術

    上傳時間: 2013-11-07

    上傳用戶:aa7821634

  • 磁芯電感器的諧波失真分析

    磁芯電感器的諧波失真分析 摘  要:簡述了改進鐵氧體軟磁材料比損耗系數和磁滯常數ηB,從而降低總諧波失真THD的歷史過程,分析了諸多因數對諧波測量的影響,提出了磁心性能的調控方向。 關鍵詞:比損耗系數, 磁滯常數ηB ,直流偏置特性DC-Bias,總諧波失真THD  Analysis on THD of the fer rite co res u se d i n i nductancShi Yan Nanjing Finemag Technology Co. Ltd., Nanjing 210033   Abstract:    Histrory of decreasing THD by improving the ratio loss coefficient and hysteresis constant of soft magnetic ferrite is briefly narrated. The effect of many factors which affect the harmonic wave testing is analysed. The way of improving the performance of ferrite cores is put forward.  Key words: ratio loss coefficient,hysteresis constant,DC-Bias,THD  近年來,變壓器生產廠家和軟磁鐵氧體生產廠家,在電感器和變壓器產品的總諧波失真指標控制上,進行了深入的探討和廣泛的合作,逐步弄清了一些似是而非的問題。從工藝技術上采取了不少有效措施,促進了質量問題的迅速解決。本文將就此熱門話題作一些粗淺探討。  一、 歷史回顧 總諧波失真(Total harmonic distortion) ,簡稱THD,并不是什么新的概念,早在幾十年前的載波通信技術中就已有嚴格要求<1>。1978年郵電部公布的標準YD/Z17-78“載波用鐵氧體罐形磁心”中,規定了高μQ材料制作的無中心柱配對罐形磁心詳細的測試電路和方法。如圖一電路所示,利用LC組成的150KHz低通濾波器在高電平輸入的情況下測量磁心產生的非線性失真。這種相對比較的實用方法,專用于無中心柱配對罐形磁心的諧波衰耗測試。 這種磁心主要用于載波電報、電話設備的遙測振蕩器和線路放大器系統,其非線性失真有很嚴格的要求。  圖中  ZD   —— QF867 型阻容式載頻振蕩器,輸出阻抗 150Ω, Ld47 —— 47KHz 低通濾波器,阻抗 150Ω,阻帶衰耗大于61dB,       Lg88 ——并聯高低通濾波器,阻抗 150Ω,三次諧波衰耗大于61dB Ld88 ——并聯高低通濾波器,阻抗 150Ω,三次諧波衰耗大于61dB FD   —— 30~50KHz 放大器, 阻抗 150Ω, 增益不小于 43 dB,三次諧波衰耗b3(0)≥91 dB, DP  —— Qp373 選頻電平表,輸入高阻抗, L ——被測無心罐形磁心及線圈, C  ——聚苯乙烯薄膜電容器CMO-100V-707APF±0.5%,二只。 測量時,所配用線圈應用絲包銅電磁線SQJ9×0.12(JB661-75)在直徑為16.1mm的線架上繞制 120 匝, (線架為一格) , 其空心電感值為 318μH(誤差1%) 被測磁心配對安裝好后,先調節振蕩器頻率為 36.6~40KHz,  使輸出電平值為+17.4 dB, 即選頻表在 22′端子測得的主波電平 (P2)為+17.4 dB,然后在33′端子處測得輸出的三次諧波電平(P3), 則三次諧波衰耗值為:b3(+2)= P2+S+ P3 式中:S 為放大器增益dB 從以往的資料引證, 就可以發現諧波失真的測量是一項很精細的工作,其中測量系統的高、低通濾波器,信號源和放大器本身的三次諧波衰耗控制很嚴,阻抗必須匹配,薄膜電容器的非線性也有相應要求。濾波器的電感全由不帶任何磁介質的大空心線圈繞成,以保證本身的“潔凈” ,不至于造成對磁心分選的誤判。 為了滿足多路通信整機的小型化和穩定性要求, 必須生產低損耗高穩定磁心。上世紀 70 年代初,1409 所和四機部、郵電部各廠,從工藝上改變了推板空氣窯燒結,出窯后經真空罐冷卻的落后方式,改用真空爐,并控制燒結、冷卻氣氛。技術上采用共沉淀法攻關試制出了μQ乘積 60 萬和 100 萬的低損耗高穩定材料,在此基礎上,還實現了高μ7000~10000材料的突破,從而大大縮短了與國外企業的技術差異。當時正處于通信技術由FDM(頻率劃分調制)向PCM(脈沖編碼調制) 轉換時期, 日本人明石雅夫發表了μQ乘積125 萬為 0.8×10 ,100KHz)的超優鐵氧體材料<3>,其磁滯系數降為優鐵

    標簽: 磁芯 電感器 諧波失真

    上傳時間: 2013-12-15

    上傳用戶:天空說我在

  • 開關電源EMI設計(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.

    標簽: EMI 開關電源 英文

    上傳時間: 2013-11-16

    上傳用戶:萍水相逢

  • vs.lib is a math library in C++ with a set of linear algebra and integrable / differentiable objects

    vs.lib is a math library in C++ with a set of linear algebra and integrable / differentiable objects. vs.lib is a rapid-proto-typing tool which makes programming in numerical applications as easy as writing mathematical expressions.

    標簽: differentiable integrable algebra library

    上傳時間: 2015-03-03

    上傳用戶:PresidentHuang

  • 算法ebook(10部算法經典著作的合集) 算法ebook> 10部算法經典著作的合集 chm格式 (1)Fundamentals of Data Structures by Ellis Hor

    算法ebook(10部算法經典著作的合集) 算法ebook> 10部算法經典著作的合集 chm格式 (1)Fundamentals of Data Structures by Ellis Horowitz and Sartaj Sahni (2)Data Structures, Algorithms and Program Style Using C by James F. Korsh and Leonard J. Garrett (3)Data Structures and Algorithm Analysis in C by Mark Allen Weiss (4)Data Structures: From Arrays to Priority Queues by Wayne Amsbury (5)Information Retrieval: Data Structures & Algorithms edited by William B. Frakes and Ricardo Baeza-Yates (6)Introduction to Algorithms by Thomas H. Cormen, Charles E. Leiserson, and Ronald L. Rivest (7)Practical Data Structures in C++ by Bryan Flamig (8)Reliable Data Structures in C by Thomas Plum (9)Data Structures and Algorithms Alfred V. Aho, Bell Laboratories, Murray Hill, New Jersey John E. Hopcroft, Cornell University, Ithaca, New York Jeffrey D. Ullman, Stanford University, Stanford, California (10)DDJ Algorithms and Data Structures Articles

    標簽: ebook Fundamentals Structures Ellis

    上傳時間: 2015-04-04

    上傳用戶:tfyt

  • TC 2.0 挖地雷 關于TC2.0版的挖地雷 1、整個游戲基于事件驅動的工作方式

    TC 2.0 挖地雷 關于TC2.0版的挖地雷 1、整個游戲基于事件驅動的工作方式,這一點和windows應用程序是相通的。在程序的主 干中,不停的捕捉鼠標事件,再通過一個函數: Bool analysis(CPoint point, ClickInfor infor) 來分析鼠標事件作用在哪個對象上(游戲中的元素,比如按鈕、菜單、地雷單元格都是 作為一個對象來看待),然后把鼠標事件分配到相應的對象上。不同的對象,對鼠標事件 有自己的事件處理函數,比如菜單的事件處理函數有兩個:單擊菜單項和鼠標焦點落在 菜單項上。菜單對象能夠依據analysis傳給它的擊鍵信息,來判斷到底調用哪個事件處 理函數。(在windows編程中,其實也是給對象或控件寫事件處理函數)。 當然了,我這個程序中事件處理機制是非常基礎和簡單的,因為用的是TC2.0的編譯器, 所以很多東西要自己寫,會麻煩一些。 ………………詳細情況見包內文檔!

    標簽: 2.0 TC 事件驅動 工作方式

    上傳時間: 2013-12-24

    上傳用戶:佳期如夢

  • 計算所漢語詞法分析系統ICTCLAS介紹 詞是最小的能夠獨立活動的有意義的語言成分。 但漢語是以字為基本的書寫單位

    計算所漢語詞法分析系統ICTCLAS介紹 詞是最小的能夠獨立活動的有意義的語言成分。 但漢語是以字為基本的書寫單位,詞語之間沒有明顯的區分標記,因此,中文詞語分析是中文信息處理的基礎與關鍵。為此,我們中國科學院計算技術研究所在多年研究基礎上,耗時一年研制出了漢語詞法分析系統ICTCLAS(Institute of Computing Technology, Chinese Lexical Analysis System),該系統的功能有:中文分詞;詞性標注;未登錄詞識別。分詞正確率高達97%以上,未登錄詞識別召回率均高于90%,其中中國人名的識別召回率接近98%處理速度為31.5Kbytes/s。ICTCLAS的特色還在于:可以根據需要輸出多個高概率結果,有多種輸出格式,支持北大詞性標注集,973專家組給出的詞性標注集合。該系統得到了專家的好評,并有多篇論文在國內外發表。 計算所漢語詞法分析系統ICTCLAS同時還提供一套完整的動態連接庫ICTCLAS.dll和相應的概率詞典,開發者可以完全忽略漢語詞法分析,直接在自己的系統中調用ICTCLAS,ICTCLAS可以根據需要輸出多個高概率的結果,輸出格式也可以定制,開發者在分詞和詞性標注的基礎上繼續上層開發。

    標簽: ICTCLAS 漢語 計算

    上傳時間: 2014-01-02

    上傳用戶:15736969615

  • FIR Filter Design(有限沖擊響應濾波器設計)

    FIR Filter Design(有限沖擊響應濾波器設計),包括ideal bandpass filter impulse response、Modified Bessel function、Kaiser window parameters for spectral analysis等12種FIR設計matlab源代碼

    標簽: Design Filter FIR 響應濾波器

    上傳時間: 2015-05-20

    上傳用戶:Miyuki

  • matlab矩陣處理例程。A matrix processor, Matx_Proc() is developed which can be used to process and edit ma

    matlab矩陣處理例程。A matrix processor, Matx_Proc() is developed which can be used to process and edit matrices and state space models, and perform various kind of matrix analysis in a visible way.

    標簽: Matx_Proc developed processor process

    上傳時間: 2015-06-23

    上傳用戶:Breathe0125

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