非线性器件振幅调制_失真和平衡对消课件

非线性器件振幅调制_失真和平衡对消 课件 超市陈列培训课件免费下载搭石ppt课件免费下载公安保密教育课件下载病媒生物防治课件 可下载高中数学必修四课件打包下载 高频电子线路多媒体教学课件 Multimedia Teaching Courseware of High-Frequency Electronic Circuits 开 始Start 西安电子科技大学 Xidian University 开 始Start课 件 简 介 A brief introduction of the courseware 封面 Cover 目录 Content 结束 End 封面 Cover 目录 Content 结束 End 本课件讲授大学本科《高频电子线路》课程的代表 内容 财务内部控制制度的内容财务内部控制制度的内容人员招聘与配置的内容项目成本控制的内容消防安全演练内容 ??非线性器件 振幅调制,失真和平衡对消。 课件主要配合教师课堂教学使用,讲授过程中始终以教师讲述为主,课 件只提供必要的文字和图像信息。 学生本人使用该课件预习和复习功课时,可以选择向导的帮助。向导及 时提供丰富的文字讲解,起到了教师指导的作用。因为集成了向导功能,本 课件也可以作为网络课件使用。The courseware is materialized on nonlinear-device amplitude modulation, distortion, and balanced cancellation, which are representative contents of High-Frequency Electronic Circuits, a course for undergraduate students With the major purpose to assist the classroom lecturing, the courseware provides necessary literal and image information to help the teacher, who plays the main role in the lecturing The courseware itself is also a net-based one. The integrated guide timely provides detailed literal explanations for students in preparing and reviewing the course. The guidance serves as the instructions from teachers简介 Introduction 西安电子科技大学 Xidian University 简介 Introduction简 要 帮 助 A concise help 封面 Cover 目录 Content 返回 Return 封面 Cover 目录 Content 返回 Return 封面 Cover 封面 Cover 翻到封面 To the cover 帮助 Help 帮助 Help 翻到帮助页面 To the help page 没有向导的界面 The interface without the guide 目录 Content 目录 Content 翻到目录 To the content 返回 Return 返回 Return 返回上一页 To the last page 结束 End 结束 End 有向导的界面 结束放映 End the screening The interface with the guide 帮 助Help 西安电子科技大学 Xidian University 帮 助Help第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 封面 Cover 帮助 Help 结束 End 封面 Cover 帮助 Help 结束 End 您好,欢迎使用高频电子线路多媒体教学课件,请选择是否需要向导。Hello, 您好,欢迎使用高频电子线路多媒体教学课件,请选择是否需要向导。Hello, welcome to Teaching Courseware of High-Frequency Electronic Circuits. Please welcome to Teaching Courseware of High-Frequency Electronic Circuits. Please 振幅调制方法的分类 Types of amplitude modulation approaches choose if you will need a guide choose if you will need a guide 使用向导(便于浏览课件,课程预习和复习)Use the guide For courseware browsing, course preparation and reviewing 不使用向导(便于组织课堂教学)No guide For classroom lecturing organization 西安电子科技大学 Xidian University 向 导 Guide 向 导 Guide第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 封面 Cover 帮助 Help 结束 End 封面 Cover 帮助 Help 结束 End 振幅调制与解调 Amplitude modulation AM and demodulation 振幅调制方法 Amplitude modulation approaches 振幅调制信号 Amplitude modulated signals 振幅调制的关键问题 Key problem of amplitude modulation 振幅调制方法的分类 Types of amplitude modulation approaches 非线性器件调幅 Amplitude modulation with nonlinear devices 非线性器件调幅分析 Analysis of nonlinear-device AM 步骤[1] Step one 步骤[2] Step two 步骤[3] Step three 非线性器件调幅失真 Distortions of nonlinear-device AM 失真来源 Source of distortions 减小失真的方法 Methods to reduce distortions 平衡对消 Balanced cancellation 线性时变电路调幅 AM with linear time-varying circuits 西安电子科技大学 Xidian University 目 录 Content 目 录 Content第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 目录 Content 帮助 Help 结束 End 目录 Content 帮助 Help 结束 End 为了生成这些信号,我们进行振幅调制时需要解决一个关键问题,即调制信 号与载波的 为了生成这些信号,我们进行振幅调制时需要解决一个关键问题,即调制信 号与载波的 振幅调制与解调 Amplitude modulation AM and demodulation 相乘。We need to solve a key problem in the amplitude modulation to generate these 相乘。We need to solve a key problem in the amplitude modulation to generate these 振幅调制方法 Amplitude modulation approaches signals, that is, the multiplication of the modulating signal and the carrier wavesignals, that is, the multiplication of the modulating signal and the carrier wave振幅调制信号 Amplitude modulated signals 非线性器件的应用解决了前面提到的振 非线性器件的应用解决了前面提到的振 幅调制的关键问题,但又产生了新的失 振幅调制的关键问题 Key problem of amplitude modulation 幅调制的关键问题,但又产生了新的失 真问题。The above-mentioned key 真问题。The above-mentioned key 振幅调制方法的分类 Types of amplitude modulation approaches 为了解决失真问题,我们接下来寻找失 感谢使用向导。首先,我们简略浏览本次课程的内容和结构。 Thank you 为了解决失真问题,我们接下来寻找失 problem of amplitude modulation is 我们从本次课程开始学习振幅调制方法,这是第五章,振幅调制与解调的一 个 感谢使用向导。首先,我们简略浏览本次课程的内容和结构。 Thank you 我们从本次课程开始学习振幅调制方法,这是第五章,振幅调制与解调的一 个 problem of amplitude modulation is 真的来源,并由此提出减小失真的方法。 for us非线性器件调幅 ing the guide. At f irA stm , le ptl’ist b ud rie e m fly b od ru ow lat sei t on he w con ith te n non t an lid n s etar ru d cte uvi rec es 真的来源,并由此提出减小失真的方法。 重要部分。 solved by u Ins t in hg n is lon esslon ine , w are d b ee vi gi cn es to learn approaches of amplitude modulation, for using the guide. At first, let’s briefly browse the content and structure 重要部分。In this lesson, we begin to learn approaches of amplitude modulation, solved by using nonlinear devices首先,我们简要复习三种振幅调制信 号,即 To tackle the distortion problem, we’ll 首先,我们简要复习三种振幅调制信号,即 of this lesson To tackle the distortion problem, we’ll wh H ic ow h ie sve an r, t im hp e d orit san tor tt p ion or oc tion cu of rs C as h a n apte ew r 5, A mplitude modulation and of this le非线性器件调幅分析 sson Analysis of nonlinear-device AM which is an important portion of Chapter 5, Amplitude modulation and However, the distortion occurs as a new 普通调幅信号,双边带调制信号和单边带调 search for the distortion source, and 非线性器件调幅通过三个步骤 普通调幅信号,双边带调制信号和单边带调 search for the distortion source, and dep m rod obu le lm at. ion. 非线性器件调幅通过三个步骤 demodulationproblem步骤[1] Step one 制信号。First, we’ll briefly review the three 一种比较重要和常见的减小失真的方法是平衡对 then bring forward methods for 来实现。The nonlinear-device 制信号。First, we’ll briefly review the three 一种比较重要和常见的减小失真的方法是平衡对 then bring forward methods for 来实现。The nonlinear-device signals out of amplitude modulation, namely, 消技术,这是本次课程最后要学习的内容。 从分类上看,有两种基本方法可以解决该问题,即非线性器件调幅和线性时 distortion reduction步骤[2] Step two amplitude modulation is signals out of amplitude modulation, namely, 消技术,这是本次课程最后要学习的内容。 从分类上看,有两种基本方法可以解决该问题,即非线性器件调幅和线性时 distortion reductionamplitude modulation is the amB pal litan udc ee m d c od an uc lat elleat d s ion ign is al an , th im e d pou orb tan le-t and usual 变电路调幅。本次课程学习非线性器件调幅。For solution, there are two performed in three stepsthe amB pal litan udc ee m d c od an uc lat elleat d s ion ign is al an , th im e d pou orb tan le-t and usual 变电路调幅。本次课程学习非线性器件调幅。 步骤[3] Step three For solution, there are two performed in three stepssideban m de m thod odu flor at d ed is s tior gn tal ion , an red d t uh ce ti s on in, w gleh -ich will be basic types of amplitude modulation approach, namely, the amplitude sideban m de m thod odu flor at d ed is s tior gn tal ion , an red d t uh ce ti s on in, w gleh -ich will be basic types of amplitude modulation approach, namely, the amplitude 非线性器件调幅失真 Distortions of nonlinear-device AM sideban std u m die od d at ulat th ed e e sn ign d of althis lessonmodulation with nonlinear devices,and the amplitude modulation with sideban std u m die od d at ulat th ed e e sn ign d of althis lessonmodulation with nonlinear devices,and the amplitude modulation with 失真来源 Source of distortions linear time-varying circuits. The former is to be studied in this lesson linear time-varying circuits. The former is to be studied in this lesson 减小失真的方法 Methods to reduce distortions 平衡对消 Balanced cancellation 线性时变电路调幅 AM with linear time-varying circuits 继续 Continue 西安电子科技大学 Xidian University 目 录 Content 目 录 Content第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 目录 Content 帮助 Help 结束 End 目录 Content 帮助 Help 结束 End 包含所有三个频率分量的信号称为普通调幅信号, 包含所有三个频率分量的信号称为普通调幅信号, 只包含上边频分量和下边频分量的信号称为双边 调制信号 Modulating signal 只包含上边频分量和下边频分量的信号称为双边 载波 carrier wave 带调制信号,而单边带调制信号则只有上边频分 带调制信号,而单边带调制信号则只有上边频分 u t U cos ?t u t U cost ?m C Cm C 量或下边频分量中的一个。The signal with all 量或下边频分量中的一个。The signal with all three frequency components is called an three frequency components is called an 现在,我们开始学习本次课程的内容。进行振幅调制的目的是把低频 现在,我们开始学习本次课程的内容。进行振幅调制的目的是把低频 amplitude modulated signal. That only with the amplitude modulated signal. That only with the 的语音、图象等调制信号寄载到高频载波上,从而实现信息的远程无 U 的语音、图象等调制信号 Cm寄载到高频载波上,从而实现信息的远程无 upper and the lower side-frequency components upper and the lower side-frequency components 为简单起见,我们认为调制信号和载波都是单频 线传输。 Now, let ’ s start the lesson. The amplitude modulation is 为简单起见,我们认为调制信号和载波都是单频 线传输。 Now, let ’ s start the lesson. The amplitude modulation is is called a double-sideband modulated signalU is called a double-sideband modulated signal?m 信号。这里给出了它 们的时域表达式。For aimed at mounting the low-frequency audio or visual modulating 信号。这里给出了它们的时域表达式。For aimed at mounting the low-frequency audio or visual modulating The single-sideband modulated signal has only The single-sideband modulated signal has only simplicity, the modulating signal and the carrier signal onto a high-frequency carrier wave, so that the information can simplicity, the modulating signal and the carrier signal onto a high-frequency carrier wave, so that the information can one of the side-frequency componentsone of the side-frequency componentswave are supposed to be single-frequency signals be transmitted wirelessly at a long distance - +C C wave are supposed to be single-frequ C ency signalsC be transmitted wirelessly at a long distanceThese are their time-domain expressionsThese are their time-domain expressions经过调 制,得到的振幅调制信号可能包含三个频率分量。角频率为,+ 和 在频域上,调制信号和载波都可以 普通调幅信号 Amplitude modulated signal C C 经过调制,得到的振幅调制信号可能包含三个频率分量。角频率为,+ 和 在频域上,调制信号和载波都可以 C C -用其角频率和振幅表示。 的频率分量可以分别叫做载频分量,上边频 分量和下边频分量。 The After theC -用其角频率和振幅表示。 的频率分量可 以分别叫做载频分量,上边频分量和下边频分量。 The After theC 双边带调制信号 Double-sideband modulated signal modulat m ion od, t ulh at ei ob ng s tai ign ne al d an am dp t lh ite u c dar e m riod er ulated signal may contain three frequency modulat m ion od, t ulh at ei ob ng s tai ign ne al d an am dp t lh ite u c dar e m riod er ulated signal may contain three frequency compon w eave nts. T arh e e osxp e w re it sh se td h i en an th gu e lar frequencies of,+and- areCC C compon w eave nts. T arh e e osxp e w re it sh se td h i en an th gu e lar frequencies of,+and- are 单边带调制信号 Single-sideband m C od Cu lated sign C al termedf as re t qh ue e c nc ar y d riom er c ai om n b py u onesn in t, t g t hh ee u ir p per side-frequency component and the lower termedf as re t qh ue e c nc ar y d riom er c ai om n b py u onesn in t, t g t hh ee u ir p per side-frequency component and the lower side-frean qu gu enlc ar y c fr om eqp uon ene cn iets r an esp de ctivelyside-frean qu gu enlc ar y c fr om eqp uon ene cn iets r an esp de ctivelyamplitudesamplitudes继续 Continue 西安电子科技大学 Xidian University 第 1 页 Page 1 第 1 页 Page 1第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 目录 Content 帮助 Help 结束 End 目录 Content 帮助 Help 结束 End 用非线性电路进行振幅调制的方法有两种,一种是利有源器件,如晶体管或 场效应管的 用非线性电路进行振幅调制的方法有两种,一种是利有源器件,如晶体管或 场效应管的 时域:uu 非线性实现调幅,另一种是基于线性时变电路实现调幅。ThC er e are two types of 非线性实现调幅,另一种是基于线性时变电路实现调幅。There are two types of Time domain: amplitude modulation approach with the use of nonlinear circuits. One approach is to amplitude modulation approach with the use of nonlinear circuits. One approach is to 振幅调制的关键问题uu make use the nonlinear property of active devices, such as the transistor and the FETCmake use the nonlinear property of active devices, such as the transistor and the FETKey problem of amplitude The other approach is based on linear time-varying circuits. The other approach is based on linear time-varying circuits. 频域:+ ?,-modulation C C Frequency domain: + ?,- C C 振幅调制方法 Amplitude modulation approaches 振幅调制方法 Amplitude modulation approaches 为了生成前面的三种振幅调制信号,进行振幅调制时,在时域上要 为了生成前面的三种振幅调制信号,进行振幅调制时,在时域上要 将调制信号和载波相乘,在频域上看,这样的相乘会生成上边频分将调制信 号和载波相乘,在频域上看,这样的相乘会生成上边频分量和下边频分量,这个关 键问题的解决需要用到非线性电路。In 非线性器件调幅 Amplitude modulation 量和下边频分量,这个关键问题的解决需要用到非线性电路。In 非线性器件调幅 Amplitude modulation order to generate the above three amplitude modulated signals, order to generate the above three amplitude modulated signals, with nonlinear devices with nonlinear devices during the amplitude modulation, the modulating signal will be during the amplitude modulation, the modulating signal will be multiplied by the carrier wave in the time domain, which will multiplied by the carrier wave in the time domain, which will 线性时变电路调幅 Amplitude modulation 线性时变电路调幅 Amplitude modulation produce the upper and the lower side-frequency components in the produce the upper and the lower side-frequency components in the with linear time-varying circuits with linear time-varying circuits frequency domain. Nonlinear circuits are to be used to solve this frequency domain. Nonlinear circuits are to be used to solve this key problemkey problem继续 Continue 西安电子科技大学 Xidian University 第 2 页 Page 2 第 2 页 Page 2第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 目录 Content 帮助 Help 结束 End 目录 Content 帮助 Help 结束 End u t 经过 E 的偏置,产生晶体管的输入电压 u t。 be B BE u t 经过 E 的偏置,产生晶体管的输入电压 u t。 be B BE With the biasing of E upon u t, we get u t, the B be BE With the biasing of E upon u t, we get u t, the B be BE input voltage on the transistorinput voltage on the transistori t C +最后,i t 经由 LC 并联谐振回路选频,产生 C 最后,i t 经由 LC 并联谐振回路选频,产生 + C 该图实际上给出了一个放大器电路。首先,载 普通调幅信号 u t。Finally, i t flows AM C + 该图实际上给出了一个放大器电路。首先,载 普通调幅信号 u t。Finally, i t flows AM C u t u t BE 波 u t和调制信号 u t 叠加产生交流输入电 through the frequency-selecting LC parallel C u t C 波 u t和调制信号 u t 叠加产生交流输入电 through the frequency-selecting LC parallel C AM压 u t。The diagram is actually an amplifier resonant circuit, and produces an amplitude be 压 u t。The diagram is actually an amplifier resonant circuit, and produces an amplitude be u t be + circuit, where the carrier wave u t and the modulated signal u t. C AM circuit, where the carrier wave u t and the modulated signal u t. C + AM modulating signal u t are added up first to modulating signal u t are added up first to u t 接下来,在 u t 的作用下,晶体管产生输出? BE 接下来,在 u t 的作用下,晶体管产生输出 produce the alternating input voltage u tBE be produce the alternating input voltage u tbe 电流 i t。In the following, the transistor C 电流 i t。In the following, the transistor C generates the output current i t in response toC +? + generates the output current i t in response toE C E C B u t. BE u t. BE 现在我们学习第一种振幅调制方法,即非线性器件调幅方法。该方法 现在我们学习第一种振幅调制方法,即非线性器件调幅方法。该方法 的原理电路如图所示。Now we come to learn the first amplitude 的原理电路如图所示。Now we come to learn the first amplitude modulation approach, i.e., the nonlinear-device amplitude modulationmodulation approach, i.e., the nonlinear-device amplitude modulationHere is the basic circuit diagram of this approachHere is the basic circuit diagram of this approach继续 Continue 西安电子科技大学 Xidian University 第 3 页 Page 3 第 3 页 Page 3第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 目录 Content 帮助 Help 结束 End 目录 Content 帮助 Help 结束 End 步骤[1] 载波和调制信号 现在我们实时观察 u t,u t 和 u Cbe u t 现在我们实时观察 u t,u t 和 u C Cbe 相加产生输入电压t 的波形。注意载波的频率远大于调 t 的波形。注意载波的频率远大于调 制信号的频率,而其振幅也大于调制 Adding up the carrier 制信号的频率,而其振幅也大于调制 前面简要描述了非线性器件调幅的过程,在此基础 首先,我们看第一个步骤。这是在输入级回路 前面简要描述了非线性器件调幅的过程,在此基础 首先,我们看第一个步骤。这是在输入级回路 t 信号的振幅。二者叠加产生的交流输 wave and the 信号的振幅。二者叠加产生的交流输 上,我们接下来观察并研究该过程中一些值得注意 中完成的,载波 u t 和调制信号 u t 在这里 C 上,我们接下来观察并研究该过程中一些值得注意 中完成的,载波 0 u t 和调制信号 u t 在这里 C 入电压 u t 的高频振荡与载波一致, be 入电压 u t 的高频振荡与载波一致, modulating s的细节。非线性器件调幅的原理电路可以分解为输 ignal to 相叠加产生交流输入电压 u t。First, let’s be be 的细节。非线性器件调幅的原理电路可以分解为输 相叠加产生交流输入电压 u t。First, let’s be 其起伏与调制信号同步。Now, let’s 其起伏与调制信号同步。Now, let’s 入级回路,晶体管和输出级回路三部分,每部分各 focus on step one, which is accomplished in the produce the input 入级回路,晶体管和输出级回路三部分,每部分各 focus on step one, which is accomplished in the u t make a real-time observation of the make a real-time observation of the 自完成振幅调制过程的一个步骤。The process of input loop, where the carrier wave u t and the C voltage 自完成振幅调制过程的一个步骤。The process of input loop, where the carrier wave u t and the C waveforms of u t, u t and u t. It Cbe waveforms of u t, u t and u t. It the nonlinear-device amplitude modulation has modulating signal u t are added up to Cbe the nonlinear-device amplitude modulation has modulating signal u t are added up to should be noticed that the carrier wave should be noticed that the carrier wave been briefly described, based on which, we now produce the alternating input voltage u tbe t been briefly described, based on which, we now produce the alternating input voltage u tbe frequency is much higher than the frequency is much higher than the come to observe and s0 tudy some details in the come to observe and study some details in the modulating signal frequency. The same + modulating signal frequency. The same process. The basic circuit can be decomposed into + process. The basic circuit can be decomposed into can be said of their amplitudes. The + can be said of their ampu litudetsThe three parts, namely, the input loop, the transistor, u t u t BE three parts, namely, the input loop, the transistor, be C alternating input voltage u t out of be alternating input voltage u t out of and the output loop. Each part of the circuit be and the output loop. Each part of the circuit u t be the addition oscillates according to the + the addition oscillates according to the performs one step of the amplitude modulationperforms one step of the amplitude modulationcarrier wave, whereas it rises and falls u t t carrier wave, whereasit rises and falls 0 in accordance with the modulating in accordance with the modulating +signal E signalB 继续 Continue 西安电子科技大学 Xidian University 第 4 页 Page 4 第 4 页 Page 4第五章 振幅调制与解调 Chapter 5 Amplitude modulation and demodulation 在该投影过程中,我们可以发 在该投影过程中,我们可以发 目录 Content 帮助 Help 结束 End 目录 Content 帮助 Help 结束 End 现,晶体管的非线性,更确切 现,晶体管的非线性,更确切 这样我们得到了 i t 波形上的一个点。Therefore, one point on the i t C C 地说,其转移特性的非线性, 这样我们得到了 i t 波形上的一个点。Therefore, one point on the i t C C 地说,其转移特性的非线性, 如果将波形放大,我们会注意到 i t 的波形和 u t 这里给出了晶体管的转移特性 C BE 如果将波形放大,我们会注意到 i t 的波形和 u t i i 这里给出了晶体管的转移特性 C BE waveform is obtainedC C 引起了 i t 波形的变化。In w C ave form is obtainedu t 引起了 i t 波形的变化。In 的波形并不一样。 与 u t 比较而言,i t 的上半周 C 接下来,我们看第二个步骤。这是在晶体管中完 C 曲线,它描述了晶体管的输入 BE C 的波形并不一样。 与 u t 比较而言,i t 的上半周 接下来,我们看第二个步骤。这是在晶体管中完 步骤 曲线,它描述了晶体管的输入 [2] 非线性器件产生 BE C the projecting p