在無線通信系統(tǒng)全面進入3G并開始邁向 4G的過程中,使用數(shù)字預失真技術(Digital Pre-distortion,以下簡稱DPD)對發(fā)射機的功放進行線性化是一門關鍵技術。功率放大器是通信系統(tǒng)中影響系統(tǒng)性能和覆蓋范圍的關鍵部件,非線性是功放的固有特性。非線性會引起頻譜增長(spectral re-growth),從而造成鄰道干擾,使帶外雜散達不到協(xié)議標準規(guī)定的要求。非線性也會造成帶內(nèi)失真,帶來系統(tǒng)誤碼率增大的問題。
標簽: DPD 數(shù)字預失真 算法 驗證方案
上傳時間: 2013-10-19
上傳用戶:yy_cn
以某高速實時頻譜儀為應用背景,論述了5 Gsps采樣率的高速數(shù)據(jù)采集系統(tǒng)的構成和設計要點,著重分析了采集系統(tǒng)的關鍵部分高速ADC(analog to digital,模數(shù)轉(zhuǎn)換器)的設計、系統(tǒng)采樣時鐘設計、模數(shù)混合信號完整性設計、電磁兼容性設計和基于總線和接口標準(PCI Express)的數(shù)據(jù)傳輸和處理軟件設計。在實現(xiàn)了系統(tǒng)硬件的基礎上,采用Xilinx公司ISE軟件的在線邏輯分析儀(ChipScope Pro)測試了ADC和采樣時鐘的性能,實測表明整體指標達到設計要求。給出上位機對采集數(shù)據(jù)進行處理的結果,表明系統(tǒng)實現(xiàn)了數(shù)據(jù)的實時采集存儲功能。
標簽: Gsps 高速數(shù)據(jù) 采集系統(tǒng)
上傳時間: 2014-11-26
上傳用戶:黃蛋的蛋黃
Digital-to-analog converters (DACs) are prevalent inindustrial control and automated test applications.General-purpose automated test equipment often requiresmany channels of precisely controlled voltagesthat span several voltage ranges. The LTC2704 is ahighly integrated 16-bit, 4-channel DAC for high-endapplications. It has a wide range of features designed toincrease performance and simplify design.
上傳時間: 2013-11-22
上傳用戶:元宵漢堡包
Designers of signal receiver systems often need to performcascaded chain analysis of system performancefrom the antenna all the way to the ADC. Noise is a criticalparameter in the chain analysis because it limits theoverall sensitivity of the receiver. An application’s noiserequirement has a signifi cant infl uence on the systemtopology, since the choice of topology strives to optimizethe overall signal-to-noise ratio, dynamic range andseveral other parameters. One problem in noise calculationsis translating between the various units used by thecomponents in the chain: namely the RF, IF/baseband,and digital (ADC) sections of the circuit.
標簽: 數(shù)字接收器 信號鏈 噪聲分析
上傳時間: 2014-12-05
上傳用戶:cylnpy
The LM20, LM45, LM50, LM60, LM61, and LM62 are analog output temperature sensors. They have various output voltage slopes (6.25mV/°C to 17mV/°C) and power supply voltage ranges (2.4V to 10V).The LM20 is the smallest, lowest power consumption analog output temperature sensor National Semiconductor has released. The LM70 and LM74 are MICROWIRE/SPI compatible digital temperature sensors. The LM70 has a resolution of 0.125°C while the LM74 has a resolution of 0.625°C. The LM74 is the most accurate of the two with an accuracy better than ±1.25°C. The LM75 is National’s first digital output temperature sensor, released several years ago.
標簽: temperatu tiny 遠程系統(tǒng) 溫度傳感器
上傳時間: 2014-12-23
上傳用戶:yl8908
Differential Nonlinearity: Ideally, any two adjacent digitalcodes correspond to output analog voltages that are exactlyone LSB apart. Differential non-linearity is a measure of theworst case deviation from the ideal 1 LSB step. For example,a DAC with a 1.5 LSB output change for a 1 LSB digital codechange exhibits 1⁄2 LSB differential non-linearity. Differentialnon-linearity may be expressed in fractional bits or as a percentageof full scale. A differential non-linearity greater than1 LSB will lead to a non-monotonic transfer function in aDAC.Gain Error (Full Scale Error): The difference between theoutput voltage (or current) with full scale input code and theideal voltage (or current) that should exist with a full scale inputcode.Gain Temperature Coefficient (Full Scale TemperatureCoefficient): Change in gain error divided by change in temperature.Usually expressed in parts per million per degreeCelsius (ppm/°C).Integral Nonlinearity (Linearity Error): Worst case deviationfrom the line between the endpoints (zero and full scale).Can be expressed as a percentage of full scale or in fractionof an LSB.LSB (Lease-Significant Bit): In a binary coded system thisis the bit that carries the smallest value or weight. Its value isthe full scale voltage (or current) divided by 2n, where n is theresolution of the converter.Monotonicity: A monotonic function has a slope whose signdoes not change. A monotonic DAC has an output thatchanges in the same direction (or remains constant) for eachincrease in the input code. the converse is true for decreasing codes.
標簽: Converters Defini DAC
上傳時間: 2013-10-30
上傳用戶:stvnash
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
標簽: Converter Defi ADC 轉(zhuǎn)換器
上傳時間: 2013-11-12
上傳用戶:pans0ul
前面討論了很多內(nèi)容,基本上涉及了有關PCB板的絕大部分相關的知識。第二章探討了傳輸線的基本原理,第三章探討了串擾,在第四章里我們闡述了許多在現(xiàn)代設計中必須關注的非理想互連的問題。對于信號從驅(qū)動端引腳到接收端引腳的電氣路徑的相關問題,我們已經(jīng)做了一些探究,然而對于硅芯片,即處于封裝內(nèi)部的IC來說,其信號傳輸通常要通過過孔和連接器來進行,對這樣的情況我們該如何處理?在本章中,我們將通過對封裝、過孔和連接器的研究,闡述其原理,從而指導大家在設計的時候?qū)φ麄€電氣路徑進行完整地分析,即從驅(qū)動端內(nèi)部IC芯片的焊盤到接受器IC芯片的焊盤。
標簽: High-Speed Digital System desi
上傳時間: 2013-11-24
上傳用戶:maizezhen
高速數(shù)字系統(tǒng)設計下載pdf:High-Speed Digital SystemDesign—A Handbook ofInterconnect Theory and DesignPracticesStephen H. HallGarrett W. HallJames A. McCallA Wiley-Interscience Publication JOHN WILEY & SONS, INC.New York • Chichester • Weinheim • Brisbane • Singapore • TorontoCopyright © 2000 by John Wiley & Sons, Inc.speeddigital systems at the platform level. The book walks the reader through everyrequired concept, from basic transmission line theory to digital timing analysis, high-speedmeasurement techniques, as well as many other topics. In doing so, a unique balancebetween theory and practical applications is achieved that will allow the reader not only tounderstand the nature of the problem, but also provide practical guidance to the solution.The level of theoretical understanding is such that the reader will be equipped to see beyondthe immediate practical application and solve problems not contained within these pages.Much of the information in this book has not been needed in past digital designs but isabsolutely necessary today. Most of the information covered here is not covered in standardcollege curricula, at least not in its focus on digital design, which is arguably one of the mostsignificant industries in electrical engineering.The focus of this book is on the design of robust high-volume, high-speed digital productssuch as computer systems, with particular attention paid to computer busses. However, thetheory presented is applicable to any high-speed digital system. All of the techniquescovered in this book have been applied in industry to actual digital products that have beensuccessfully produced and sold in high volume.Practicing engineers and graduate and undergraduate students who have completed basicelectromagnetic or microwave design classes are equipped to fully comprehend the theorypresented in this book. At a practical level, however, basic circuit theory is all thebackground required to apply the formulas in this book.
標簽: 高速數(shù)字 系統(tǒng)設計
上傳時間: 2013-10-26
上傳用戶:縹緲
模擬集成電路的設計與其說是一門技術,還不如說是一門藝術。它比數(shù)字集成電路設計需要更嚴格的分析和更豐富的直覺。嚴謹堅實的理論無疑是嚴格分析能力的基石,而設計者的實踐經(jīng)驗無疑是誕生豐富直覺的源泉。這也正足初學者對學習模擬集成電路設計感到困惑并難以駕馭的根本原因。.美國加州大學洛杉機分校(UCLA)Razavi教授憑借著他在美國多所著名大學執(zhí)教多年的豐富教學經(jīng)驗和在世界知名頂級公司(AT&T,Bell Lab,HP)卓著的研究經(jīng)歷為我們提供了這本優(yōu)秀的教材。本書自2000午出版以來得到了國內(nèi)外讀者的好評和青睞,被許多國際知名大學選為教科書。同時,由于原著者在世界知名頂級公司的豐富研究經(jīng)歷,使本書也非常適合作為CMOS模擬集成電路設計或相關領域的研究人員和工程技術人員的參考書。... 本書介紹模擬CMOS集成電路的分析與設計。從直觀和嚴密的角度闡述了各種模擬電路的基本原理和概念,同時還闡述了在SOC中模擬電路設計遇到的新問題及電路技術的新發(fā)展。本書由淺入深,理論與實際結合,提供了大量現(xiàn)代工業(yè)中的設計實例。全書共18章。前10章介紹各種基本模塊和運放及其頻率響應和噪聲。第11章至第13章介紹帶隙基準、開關電容電路以及電路的非線性和失配的影響,第14、15章介紹振蕩器和鎖相環(huán)。第16章至18章介紹MOS器件的高階效應及其模型、CMOS制造工藝和混合信號電路的版圖與封裝。 1 Introduction to Analog Design 2 Basic MOS Device Physics 3 Single-Stage Amplifiers 4 Differential Amplifiers 5 Passive and Active Current Mirrors 6 Frequency Response of Amplifiers 7 Noise 8 Feedback 9 Operational Amplifiers 10 Stability and Frequency Compensation 11 Bandgap References 12 Introduction to Switched-Capacitor Circuits 13 Nonlinearity and Mismatch 14 Oscillators 15 Phase-Locked Loops 16 Short-Channel Effects and Device Models 17 CMOS Processing Technology 18 Layout and Packaging
上傳時間: 2014-12-23
上傳用戶:杜瑩12345