P1V1同学们好！欢迎参加本次讲座。在射频电路的学习中，我们遇到了.PDFVIP

P1V1 ：同学们好！欢迎参加本次讲座。在射频电路的学习中，我们遇到了振幅调制这个基本 概念。振幅调制负责把低频的调制信号加载到高频的载波上，生成振幅调制信号，便 于用天线实现远距离的无线发射和接收。我们想知道振幅调制是如何应用非线性器件 来实现的？同时，做为乘法器的基本运用，这一过程包含了哪些信号相乘电路的重要 设计思想？现在，我们准备研讨这些问题。Good morning students! Welcome to the lecture. In the study of radio-frequency circuits, we come to the basic concept of amplitude modulation. The amplitude modulation loads the high-frequency carrier wave with the low-frequency modulating signal. The amplitude-modulated signal is generated for wireless transmission and reception by antennas. We would like to know the modulating mechanism with the application of nonlinear devices. Meanwhile, for the basic usage of the multiplier, we are curious about the important ideas implied in the procedure to design the circuit for signal multiplication. Now, we are ready to study and discuss these topics. P2V1 ：这里给出了振幅调制的知识结构。This is the knowledge structure of the amplitude modulation. P2V2 ：本次讲座中，我们首先复习三种振幅调制信号，即普通调幅信号、双边带调制信号和 单边带调制信号。In this lecture, well briefly review the three signals out of amplitude modulation, namely, the standard amplitude-modulated signal, the double-sideband modulated signal, and the single-sideband modulated signal. P2V3 ：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 的相乘。To generate these signals, we need to solve a key problem in the amplitude modulation, that is, the multiplication of the modulating signal and the carrier wave. P2V4 ：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变电路调 幅。There are two basic approaches for the solution, namely, the amplitude modulation with nonlinear devices and the amplitude modulation with linear time-varying circuits. P2V5 ：非线性器件调幅分为三个基本步骤，它们分别完成载波和调制信号的输入、信号的非 线性变换，以及振幅调制信号的输出。The nonlinear-device amplitude modulation is