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Frequency-hopping

  • 差分電路中單端及混合模式S-參數的使用

    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frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element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.

    标签: 差分電路 單端 模式

    上传时间: 2014-03-25

    上传用户:yyyyyyyyyy

  • S参数的设计与应用

    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

  • 半导体器件物理与设计

    It would not be an exaggeration to say that semiconductor devices have transformed humanlife. From computers to communications to internet and video games these devices and the technologies they have enabled have expanded human experience in a way that is unique in history. Semiconductor devices have exploited materials, physics and imaginative applications to spawn new lifestyles. Of course for the device engineer, in spite of the advances, the challenges of reaching higher frequency, lower power consumption, higher power generation etc.

    标签: 半导体器件 物理

    上传时间: 2013-10-28

    上传用户:songnanhua

  • XAPP708 -133MHz PCI-X到128MB DDR小型DIMM存储器桥

      The Virtex-4 features, such as the programmable IDELAY and built-in FIFO support, simplifythe bridging of a high-speed, PCI-X core to large amounts of DDR-SDRAM memory. Onechallenge is meeting the PCI-X target initial latency specification. PCI-X Protocol Addendum tothe PCI Local Bus Specification Revision 2.0a ([Ref 6]) dictates that when a target signals adata transfer, "the target must do so within 16 clocks of the assertion of FRAME#." PCItermination transactions, such as Split Response/Complete, are commonly used to meet thelatency specifications. This method adds complexity to the design, as well as additional systemlatency. Another solution is to increase the ratio of the memory frequency to the PCI-X busfrequency. However, this solution increases the required power and clock resource usage.

    标签: PCI-X XAPP DIMM 708

    上传时间: 2013-11-24

    上传用户:18707733937

  • 微电脑型单相交流集合式电表(单相二线系统)

    微电脑型单相交流集合式电表(单相二线系统) 特点: 精确度0.25%满刻度±1位数 可同时量测与显示交流电压,電流,頻率,瓦特,(功率因數/視在功率) 交流電壓,電流,瓦特皆為真正有效值(TRMS) 交流電流,瓦特之小數點可任意設定 瓦特單位W或KW可任意設定 CT比可任意設定(1至999) 輸入與輸出絕緣耐压 2仟伏特/1分鐘( 突波測試強度4仟伏特(1.2x50us) 數位RS-485界面 (Optional) 主要规格: 精确度: 0.1% F.S.±1 digit (Frequency) 0.25% F.S.±1 digit(ACA,ACV,Watt,VA) 0.25% F.S. ±0.25o(Power Factor) (-.300~+.300) 输入负载: <0.2VA (Voltage) <0.2VA (Current) 最大过载能力: Current related input: 3 x rated continuous 10 x rated 30 sec. 25 x rated 3sec. 50 x rated 1sec. Voltage related input: maximum 2 x rated continuous 过载显示: "doFL" 显示值范围: 0~600.0V(Voltage) 0~999.9Hz(Frequency)(<20% for voltage input) 0~19999 digit adjustable(Current,Watt,VA) 取样时间: 2 cycles/sec. RS-485通讯位址: "01"-"FF" RS-485传输速度: 19200/9600/4800/2400 selective RS-485通信协议: Modbus RTU mode 温度系数: 100ppm/℃ (0-50℃) 显示幕: Red high efficiency LEDs high 10.16 mm(0.4") 参数设定方式: Touch switches 记忆型式: Non-volatile E²PROM memory 绝缘抗阻: >100Mohm with 500V DC 绝缘耐压能力: 2KVac/1 min. (input/output/power) 1600 Vdc (input/output) 突波测试: ANSI c37.90a/1974,DIN-IEC 255-4 impulse voltage 4KV(1.2x50us) 使用环境条件: 0-50℃(20 to 90% RH non-condensed) 存放环境条件: 0-70℃(20 to 90% RH non-condensed) CE认证: EN 55022:1998/A1:2000 Class A EN 61000-3-2:2000 EN 61000-3-3:1995/A1:2001 EN 55024:1998/A1:2001

    标签: 微电脑 单相交流 单相 电表

    上传时间: 2015-01-03

    上传用户:几何公差

  • XAPP713 -Virtex-4 RocketIO误码率测试器

      The data plane of the reference design consists of a configurable multi-channel XBERT modulethat generates and checks high-speed serial data transmitted and received by the MGTs. Eachchannel in the XBERT module consists of two MGTs (MGTA and MGTB), which physicallyoccupy one MGT tile in the Virtex-4 FPGA. Each MGT has its own pattern checker, but bothMGTs in a channel share the same pattern generator. Each channel can load a differentpattern. The MGT serial rate depends on the reference clock frequency and the internal PMAdivider settings. The reference design can be scaled anywhere from one channel (two MGTs)to twelve channels (twenty-four MGTs).

    标签: RocketIO Virtex XAPP 713

    上传时间: 2013-12-25

    上传用户:jkhjkh1982

  • 运算放大器稳定时间的测量

    The AN10 begins with a survey of methods for measuring op amp settling time. This commentary develops into circuits for measuring settling time to 0.0005%. Construction details and results are presented. Appended sections cover oscilloscope overload limitations and amplifier frequency compensation.

    标签: 运算放大器 稳定时间 测量

    上传时间: 2013-11-14

    上传用户:JIMMYCB001

  • 基于MASON公式的多功能二阶通用滤波器设计

    基于通用集成运算放大器,利用MASON公式设计了一个多功能二阶通用滤波器,能同时或分别实现低通、高通和带通滤波,也能设计成一个正交振荡器。电路的极点频率和品质因数能够独立、精确地调节。电路使用4个集成运放、2个电容和11个电阻,所有集成运放的反相端虚地。利用计算机仿真电路的通用滤波功能、极点频率和品质因数的独立控制和正交正弦振荡,从而证明该滤波器正确有效。 Abstract:  A new multifunctional second-order filter based on OPs was presented by MASON formula. Functions, such as high-pass, band-pass, low-pass filtering, can be realized respectively and simultaneously, and can become a quadrature oscillator by modifying resistance ratio. Its pole angular frequency and quality factor can be tuned accurately and independently. The circuit presented contains four OPs, two capacitors, and eleven resistances, and inverting input of all OPs is virtual ground. Its general filtering, the independent control of pole frequency and quality factor and quadrature sinusoidal oscillation were simulated by computer, and the result shows that the presented circuit is valid and effective.

    标签: MASON 多功能 二阶 滤波器设计

    上传时间: 2013-10-09

    上传用户:13788529953

  • 基于Multisim 10的矩形波信号发生器仿真与实现

    在Multisim 10软件环境下,设计一种由运算放大器构成的精确可控矩形波信号发生器,结合系统电路原理图重点阐述了各参数指标的实现与测试方法。通过改变RC电路的电容充、放电路径和时间常数实现了占空比和频率的调节,通过多路开关投入不同数值的电容实现了频段的调节,通过电压取样和同相放大电路实现了输出电压幅值的调节并提高了电路的带负载能力,可作为频率和幅值可调的方波信号发生器。Multisim 10仿真分析及应用电路测试结果表明,电路性能指标达到了设计要求。 Abstract:  Based on Multisim 10, this paper designed a kind of rectangular-wave signal generator which could be controlled exactly composed of operational amplifier, the key point was how to implement and test the parameter indicators based on the circuit diagram. The duty and the frequency were adjusted by changing the time constant and the way of charging and discharging of the capacitor, the width of frequency was adjusted by using different capacitors provided with multiple switch, the amplitude of output voltage was adjusted by sampling voltage and using in-phase amplifier circuit,the ability of driving loads was raised, the circuit can be used as squarewave signal generator whose frequency and amplitude can be adjusted. The final simulation results of Multisim 10 and the tests of applicable circuit show that the performance indicators of the circuit meets the design requirements.

    标签: Multisim 矩形波 信号发生器 仿真

    上传时间: 2014-01-21

    上传用户:shen007yue

  • Arduino 328控制板制作音乐

       要生产音频脉冲,只要算出某一音频的周期(1/频率),可以利用定时器计时的方式得到此频率的脉冲。而Arduino平台“封装”了新的数字输出函数tone()。更简易的实现喇叭和蜂鸣器唱歌。 tone(pin, frequency),Arduino会向指定pin发送制定频率的方波,执行noTone()函数来停止。 tone(pin, frequency, duration方法多了一个参数,代表发送方波持续的时间,到时自动停止发送信号,就不需要noTone()函数。 利用tone()函数播放音乐,只需要查表了解各个音符对应的频率,还要求个人稍微能看懂音乐谱子的节拍。 物料清单 : Arduino 328控制板 1块 8Ω 0.5W的喇叭(或者蜂鸣器) 1个(ATmega328的驱动能力足够,直接拉电流就ok!) 12Ω电阻(限流) 1个 实物图:

    标签: Arduino 328 控制板 制作音乐

    上传时间: 2013-10-14

    上传用户:jiangxiansheng