通信专业英语pdf

Trigger Coupling (Coupling) mode selection trigger signal to trigger circuit coupled in different ways, the purpose is to trigger a stable and reliable. Here are a few commonly used. AC-coupling is also called capacitive coupling. It only allows the exchange of components of the trigger signal trigger, trigger signal DC component has been cut off. DC component is usually not considered when the use of this coupling in order to form a stable trigger. However, if the trigger signal frequency is less than 10Hz, would cause trigger problems. DC-coupled (DC) does not cut off the DC component of the trigger signal. When the trigger signal or trigger signal the frequency of the lower duty cycle is large, the use of DC-coupled better. low-frequency suppression (LFR) is triggered when the trigger signal through the high-pass filter added to the trigger circuit to trigger low-frequency signal component is suppressed; high-frequency suppression (HFR) is triggered when the trigger signal through the low-pass filter added to the trigger circuit, trigger signal high-frequency components was inhibited. There are also synchronization for television repair television (TV) is triggered. Trigger coupling of these have their own scope of application is required to experience in use. 3. Trigger level (Level) and the trigger polarity (Slope) trigger level adjustment is also called the simultaneous regulation, which makes scanning and measured signal synchronization. Level adjustment knob adjustment trigger signal of the trigger level. Once the trigger signal exceeds a trigger set by knob usual, scan Jibei trigger. Clockwise rotation knob, trigger level rise; counterclockwise rotation knob, trigger level down. When the power level knob transferred to level the locked position, the trigger level automatically maintained within the range of the trigger signal, without level regulation can generate a stable trigger. When the signal waveform complex, a stable power level knob can not be triggered,With the release inhibition (Hold Off) waveforms of the release knob adjustment suppression time (scan pause time), can scan and waveform stability of synchronization. polarity switch is used to select the polarity of the trigger signal. Dial the "+" position when the direction of the signal increases, when the trigger signal is generated more than usual Trigger trigger. Dial in the "-" position when, in the direction of the signal to reduce, when the trigger signal is generated more than usual Trigger trigger. Trigger polarity and trigger level trigger signal jointly determined trigger point. 2.6 scan mode (SweepMode) scan automatic (Auto), normal (Norm) and single (Single) three kinds of scan mode. Auto: When no triggering signal input, or when the trigger signal frequencies below 50Hz, scan for the self-excited mode. Normal: When no trigger signal input, the scan at the preparatory level, there is no scan lines. After the arrival of trigger signals to trigger scan. Single: Single-button similar to the reset switch. Single-scan mode, press a single button to reset the circuit when the scan at this time ready (Ready) lights. Trigger signal generated from the arrival of a scan. After a single scan in preparation for lights eliminate. A single scan for the observation of non-periodic signal, or a single transient signals often need to take pictures of the waveform. outlined above describes the basic functions and operation of the oscilloscope. Oscilloscope there are other more complex functions, such as the delayed scanning, triggering delays, XY working methods and so on, is not presented here. Oscilloscope entry operation is easy, really skilled in the application will have to master. It is worth noting that, although the function of the oscilloscope more, but in many cases other instruments, meters and better. For example, in digital circuit experiment, a pulse width to determine whether the narrow single pulse occurs, with the logic of simple multi-pen; measurement of single pulse width, used logic analyzer better.1. The acquisition of baseline: When the operator instructions in the use of non-use of the oscilloscope, the first to get one of the most detailed level of the baseline, and then the probe can be used for other measurements, the specific methods are as follows: (1) preset panel of switches, knobs. set moderate intensity, focus and support focus set is moderate, the vertical input coupling set "AC,,, the vertical voltage range selection set" 5mv/div ", select the vertical methods of work home" CHl ", fine-tune the calibration of the vertical position of the sensitivity set" CAL ", the vertical channel sync source selection set the middle position, the vertical position of the middle set, A and B together with pre-scan time-factor in the" 0.5ms/div ", A scan time fine-tuning the calibration set position" CAL'', horizontal displacement of set intermediate position, scanning work home "A", triggering synchronous way home "AUTO", the slope of switch set "+"

本书结合通信专业特点，收集常用专业词汇及技术资料，力求实现职场英语及专业阅读的有机融合。本书以通信专业实用英语为背景，从通信技术的发展开始，精心选取了移动通信终端、无线网络优化、物联网等最新英文技术资料，同时，面向客户服务、通信工程师、通信设备安装与维护等工作岗位进行了有针对性的介绍。本书从教学项目设计、辅助教学资料编制、背景资料准备、译文、典型词汇总结，到有针对性的课后练习，较完整地体现了通信专业英语教学理念和方法，有助于学生学习和教师教学。

UNIT 1The Development of Communication Technology1Reading 1Fiber-optic Communication1NEW WORDS AND PHRASES2NOTES3Reading 2Wireless Network Transmission Technology4NEW WORDS AND PHRASES7NOTES8Reading 3The 4th Generation Mobile Communication System9NEW WORDS AND PHRASES12NOTES13EXERCISES14DO IT YOURSELF18参考译文19UNIT 2Mobile Communication Terminals24Reading 1iPhone in Business24NEW WORDS AND PHRASES25NOTES26Reading 2BlackBerry27NEW WORDS AND PHRASES29NOTES29Reading 3The iPad31NEW WORDS AND PHRASES33NOTES34Reading 4A GPS Navigation Device35NEW WORDS AND PHRASES36NOTES37EXERCISES38DO IT YOURSELF40参考译文40UNIT 3Radio Network Optimization45Reading 1WCDMA/UMTS Optimization Methodology45NEW WORDS AND PHRASES48NOTES49Reading 2Wireless/Radio-Frequency Engineering Services50NEW WORDS AND PHRASES52NOTES53EXERCISES53DO IT YOURSELF56参考译文57UNIT 4The Internet of Things62Reading 1The Internet of Things62NEW WORDS AND PHRASES64NOTES65Reading 2Touchatag66NEW WORDS AND PHRASES67NOTES68EXERCISES69DO IT YOURSELF72参考译文73UNIT 5Customer Service76Reading 1Five Simple Steps to Extraordinary Customer Service76NEW WORDS AND PHRASES77NOTES79Reading 2Customer Service80NEW WORDS AND PHRASES81NOTES82EXERCISES83DO IT YOURSELF85参考译文86UNIT 6A Telecommunications Engineer89ReadingTelecom Engineers89NEW WORDS AND PHRASES92NOTES94EXERCISES96DO IT YOURSELF98参考译文98UNIT 7Communication Equipment Installers and Repairers101ReadingRadio and Telecommunications Equipment Installers and Repairers101NEW WORDS AND PHRASES106NOTES106EXERCISES107DO IT YOURSELF109参考译文110UNIT 8Sustainability113ReadingSustainability113NEW WORDS AND PHRASES117NOTES119EXERCISES120DO IT YOURSELF123参考译文123AppendixVOCABULARY127