电子信息专业英语.pdf

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1、.实用文档.第三单元 1.Use of custom gate array logic,application specific integrated circuits(ASICs),ball grid arrays(BGAs),multichip modules(MUMs),and digital devices operating in the subnanosecond range present new and challenging opportunities for EMC engineers.定制门阵列逻辑、专用集成电路、球栅阵列、多芯片模块和亚纳米数字器件的使用为兼容工程师提供

2、了新的挑战机遇。2.A resistor at high frequency acts like a series combination with the resistor in parallel with a capacitor.A capacitor at high frequency acts like an inductor and resistor in resistor in series combination with the capacitor plates.工作在高频的电阻表现为电感和并联的电阻、电容之间的级联。工作在高频的电容、电阻、电感的级联。9.在数字系统中，串扰是

3、非常普遍的。在芯片上，印制电路板上，芯片封装上和连接电缆上都可能出现串扰。In digital designs the occurrence of crosstalk is very widespread.Crosstalk will occur on the chip,on the PCB board,on the connectors,on the chip package,and on the connector cables.10.许多系统工作在高频上，导体在这些频率上不再仅仅表现为导线，而是展现出高频效应并表现为传输线。如果没有正确处理这些传输线，就可能在无意中破坏了系统时序。.实用

4、文档.Many systems operate at high frequencies at which conductors no longer behave as simple wires,but instead exhibit high-frequency effects and behave as transmission lines.If these transmission lines are not handled properly,they can unintentionally ruin system timing.第四单元 1.The available spectrum

5、bandwidth 不同的无线射频链路以不同的方式共用频谱宽度。这些共用方式称为“多址模式。“频分多址(FDMA)“时分多址(TDMA)“码分多址(CDMA)“空分多址(SDMA)是四种主要的多址模式。7.在频分多址和时分多址系统中，一旦信道(频率或时隙)分配给用户，该信道在非活动期间也不能被利用。In FDMA and TDMA systems once a channel(frequency and/or tine slot)is allocated to user,that channel cannot be used during nonactivity periods.8.“蜂窝概念

6、是由贝尔实验室创造的。1983 年 10 月，在芝加哥出现了第一个商用模拟语音系统。The cellular concept was invented by Bell Laboratories and the first commercial analog voice system was introduced in Chicago in October 1983.9.第三代系统的目的在于为用户提供一个语音、数据、多媒体和视频效劳的无缝网络，而不管用户在网络中的什么位置。.实用文档.The third-generation systems aim to provide a seamless network that can provide users voice,data,multimedia,and video services regardless of their location on the network.