专业英语试题一、词语翻译1.Electromagnetic induction 电磁感应2.Broadcasting 广播3.发射机Transmitter4.Encoder 编码器5.光电阴极Photocathode6.像素Pixel7.Harmonic structure 谐波结构8.多路器Mutiplexer9.电离层Ionosphere10.Deterministic 确定的11.功率谱密度power clensity spectrum12.信噪比signal-to-noise ratio13.Demodulation 解调，检波14.Nonlinear 非线性的15.Vacuum-tube 真空（电子）管16.Modulation coefficient 调制系数17.Upper side frequency 上边频18.调制信号modulation signal19.直流电源DC power suply20.Quadrature 正交21.振荡器resonator22.Inversion 倒置23.差分difference24.Cascade 串联，级联25.Deemphasis 去加重1.field-effect 场效应管2.oscilloscope 示波器rmation 信息，消息，情报4.optical fiber 光纤5. signal-to-noise 信噪比6.bandwidth 基带7.vocal tract 声带8.bipolar 双极（线）的9.decoder 解（译）码器10.Fourier series 傅里叶级数11.decibel 分贝12.modulation 调制，调节13.amplifier 放大器，扩音机14. transformer 变压器15.resonator 振荡器16.prescribe 指示，规定17.difference差分，差别18.frequency modulation调频19.frequency divider分频器20.viewpoint 观点21.impurity杂质，混合物22.nanometers纳米23.packaging封装24.very large integration 超大规模集成电路25.digital signal processing数字信号处理26. baseband 基带27.binary二进制编码28.mainframe 主机，大型机29.electronic mail电子邮件30.mobile telephone service移动电话业务二、英译汉1.A serial link is often used to attach a computer to a modem.答案：串口通常用来将计算机和调制解调器连接起来。
2.In the data communications world, data generally are defined as information thatis stored in digital form.答案：在数据通信领域，数据通常定义成以数字形式存储的信息。
rmation that has been processed, organized, and stored is called data.答案：经过处理、组织和存储的信息成为数据。
4.Modern communication systems use digital modulation techniques.答案：现代通信系统采用的是数字调制技术。
5.Digital modulation offers many advantages over analog modulation.答案：数字调制比模拟调制有更多的优点。
6.In a digital communication system, in order to increase noise immunity, it isnecessary to increase the signal power.答案：在数字通信系统中，为了增加抗噪性能，需要提高信号的功率。
7.The idea of communication by light probably goes back to signal fires on prehistorichilltops.答案：用光来通信的想法大概可追溯到史前的山顶上的信号火。
8.Phase modulation(PM) and frequency modulation(FM) are special cases of anglemodulated signaling.答案：相位调制和频率调制是角度调制信号传输的特例。
rmation signals are transported between a transmitter and a receiver over someform of transmission medium.答案：信息信号通过某种介质在发射机与接收机之间传送。
10.AM modulators are nonlinear devices with two inputs and one output.答案：幅度调制器是有两个输入和一个输出的非线性器件。
11.The fundamental purpose of an electronic communication system is to transferinformation from one place to another.答案：电子通信系统的基本作用是把信息从此地传送到彼地。
（1）Integrated circuits are more of a science,than of a technology.答案：集成电路与其说是技术，不如说是科学。
（2）The bandwidth of an information signal is the difference between the highest and lowest frequencies contained in the information,and the bandwidth of a communications channel is the difference between the highest and lowest frequencies that the channel will allow to pass through it. 答案：信息信号的带宽就是信息中包含的最高和最低频率之间的频差，通信信道的带宽是可通过该信道的最高和最低频率之差。
（3）In its simplest form,a waveform generator is an oscillator circuit that generates well-defined,stable waveforms that can be externally modulated or swept over a given frequency range.答案：在最简单的情况下，波形发生器就是一个震荡器，他产生预定的稳定波形，然后再进行调制，或在给定的频率范围内扫描。
（4）In order to reduce the effect of frequency error distortion in telephone system,we have to limit the frequency error to 2-5 HZ.答案：为了减轻电话系统中的频率误差的影响，我们必须将误差控制在2-5赫兹。
（5）Probably the most significant advantage of angle modulation transmission (FM and PM) over amplitude modulation transmission is noise immunity.答案:与幅度调制传输相比，角度调制传输（FM和PM）最主要的优点是抗噪声性能好。
（6）Because laser wavelength is temperature-sensitive,the control circuits also monitor temperature and control coolers when they are included.答案：因为激光波长队温度敏感，控制电路需要监控温度，如果有冷却器的话，还要控制他们。
（7）The simplest digital modulation techniques is digital amplitude modulation,which is simply double-sideband,full-carrier amplitude modulation where the input modulating signal is a binary waveform.答案：最简单的数字调制技术上数字调幅，这种技术是简单的双边带，全载波幅度调制，只是输入的调制信号是二进制波形。
（8）One disadvantage of echoplex,however,occurs when a transmitted character has been received correctly,then a transmission error occurs while it is being sent back to the originator.答案：当传送的字符已经正确接收，但是在回送的时候却发生了传输错误，这时就会造成一次不必要的重传，这就是回送的一个缺点。
（9）The key innovation in telephony are circuits switching,digitization,separation of call control from voice transfer ,optical links,and service integration.答案：电话技术中关键的革新有电路交换、数字化、语音传输与呼叫控制的独立、光链接以及综合业务。
（10）Transmissions from base stations to mobile units are called forward links and transmissions from mobile units to base stations are called reverse links.答案：基站到移动电话之间的传输称为前向链路，而移动电话到基站之间的传输则称为反向链路。