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frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element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
用二端口S-参数来表征差分电路的特性■ Sam Belkin差分电路结构因其更好的增益，二阶线性度，突出的抗杂散响应以及抗躁声性能而越来越多地被人们采用。这种电路结构通常需要一个与单端电路相连接的界面，而这个界面常常是采用“巴伦”器件（Balun），这种巴伦器件提供了平衡结构-到-不平衡结构的转换功能。要通过直接测量的方式来表征平衡电路特性的话，通常需要使用昂贵的四端口矢量网络分析仪。射频应用工程师还需要确定幅值和相位的不平衡是如何影响差分电路性能的。遗憾的是，在射频技术文献中，很难找到一种能表征电路特性以及衡量不平衡结构所产生影响的好的评估方法。这篇文章的目的就是要帮助射频应用工程师们通过使用常规的单端二端口矢量网络分析仪来准确可靠地解决作为他们日常工作的差分电路特性的测量问题。本文介绍了一些用来表征差分电路特性的实用和有效的方法， 特别是差分电压，共模抑制（CMRR），插入损耗以及基于二端口S-参数的差分阻抗。差分和共模信号在差分电路中有两种主要的信号类型：差分模式或差分电压Vdiff 和共模电压Vcm（见图2）。它们各自的定义如下[1]：• 差分信号是施加在平衡的3 端子系统中未接地的两个端子之上的• 共模信号是相等地施加在平衡放大器或其它差分器件的未接地的端子之上。
上传时间： 2013-10-14
上传用户：叶山豪
Agilent AN 154 S-Parameter Design Application Note S参数的设计与应用 The need for new high-frequency, solid-state circuitdesign techniques has been recognized both by microwaveengineers and circuit designers. These engineersare being asked to design solid state circuitsthat will operate at higher and higher frequencies.The development of microwave transistors andAgilent Technologies’ network analysis instrumentationsystems that permit complete network characterizationin the microwave frequency rangehave greatly assisted these engineers in their work.The Agilent Microwave Division’s lab staff hasdeveloped a high frequency circuit design seminarto assist their counterparts in R&D labs throughoutthe world. This seminar has been presentedin a number of locations in the United States andEurope.From the experience gained in presenting this originalseminar, we have developed a four-part videotape, S-Parameter Design Seminar. While the technologyof high frequency circuit design is everchanging, the concepts upon which this technologyhas been built are relatively invariant.The content of the S-Parameter Design Seminar isas follows:
标签： S参数
上传时间： 2013-12-19
上传用户：aa54
s参数计算器,S11,S12,S22,S21的参数，一算变知，非常方便。
上传时间： 2013-11-21
上传用户：432234
Vmlab是AVR系列单片机的一个纯软件模拟仿真工具。 从V3.12开始，它变成了免费的版本。Vmlab还能仿真ST62系列的单片机。
上传时间： 2014-12-31
上传用户：啊飒飒大师的
本书针对AVR系列单片机,详细介绍了单片机的结构原理、指令系统、内部资源和外部扩展功能等内容。
上传时间： 2013-10-23
上传用户：sssnaxie
基于LPCEB2000-S的SPI程序
上传时间： 2013-11-12
上传用户：540750247
串口通迅测试，当收到8个以上字符时就将收到的字符再发送出去，波特率为9600。基于LPCEB2000-S的串口程序
上传时间： 2013-11-04
上传用户：dvfeng
TKScope仿真AVR驱动程序 AVR Studio环境
上传时间： 2013-11-21
上传用户：shus521
摘要：介绍了AVR单片机在控制步进电机方面的应用，对系统的软件和硬件设计做了说明。这是一个自动翻页拍照的图书录入系统，该系统以ATmega32L为核心，通过ICCV7 for AVR和步进电机的细分驱动器对脉冲频率进行设定，进而控制翻页和拍照装置的精确位置。和传统的图书录入相比，系统具有可靠性高、实用性强、易于操作等特点。
上传时间： 2013-11-17
上传用户：digacha
