通信工程专业英语 Lesson 13 Phase-Locked Loops 第13课 锁相环 邓 磊 denglei@dgut.edu.cn https://leideng.github.io/communication-english/ (Some pictures are from the Internet) 东莞理工学院 电子工程与智能化学院 2018.10.16/17
Outline Technical Contents Technical Terms Structures and Sentences PLL Configuration 锁相环结构 PLL Applications 锁相环应用 Technical Terms Structures and Sentences
Introduction to Phase-Locked Loop (PLL) PLL is a control system that generates an output signal whose phase has a fixed difference to the phase of the input signal. A nice video introduction to PLL: https://www.youtube.com/watch?v=A9qt0JYdvFU
Technical Contents: PLL Configuration Phase Detector 鉴相器 Low-Pass Filter 低通滤波器 Amplifier 放大器 Voltage-Controlled Oscillator (VCO) 压控振荡器
Technical Contents: PLL Applications FM Detection 调频检测
A Simple PLL Example MATLAB Code: https://www.mathworks.com/matlabcentral/fileexchange/24167-simple-pll-demostration?focused=5114977&tab=function
A Simple PLL Example
Technical Contents: PLL Applications FM Detection 调频检测
Technical Contents: PLL Applications AM Detection 调幅检测
Technical Contents: PLL Applications AM Detection 调幅检测
Technique Terms amplifier n. 放大器 oscillator n. 振荡器 instantaneous adj. 瞬态的 jitter n. 抖动 phase detector 鉴相器 clocking pulse 定时脉冲 integrated circuit (IC) 集成电路 feedback resistor 反馈电阻 Voltage-Controlled Oscillator (VCO) 压控振荡器
Structures and Sentences The phase detector is a device that compares two input frequencies, generating an output that is a measure of their phase difference (if, for example, they differ in frequency, it gives a periodic output at the difference frequency). 鉴相器是这样一个设备：他比较两个输入信号的频率，然后产生一个体现两个输入信号的相位差的信号。（比如，如果两个信号有频差的话，鉴相器的输出信号是一个以此频差为频率的周期信号。）
Structures and Sentences In frequency modulation, information is encoded onto a “carrier” signal by varying its frequency proportional to the information waveform. 在频率调制中，载波信号频率随着信息波形而变化，从而将信息编码到载波上。
Structures and Sentences Multiplying the input signal by this square wave generates a full-wave-rectified signal that only needs some low-pass filtering to remove the remnants of the carrier frequency, leaving the modulation envelope. 输入信号乘以这个方波信号就会产生一个全波整流信号，其只需低通滤波就可以去除残余载波频率，从而留下调制包络。
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