摘要：负反馈放大电路是模拟电路课程中的重要内容，负反馈是以牺牲电路增益为代价，能改良放大电路的性能，因此探究负反馈放大电路有很大意义。本文用Multisim软件对负反馈放大电路进行仿真，既加深对理论的理解，又提高了动手能力，还得出数据更好的分析反馈电路对放大器增益的稳定性，减小非线性失真，扩大带宽，改变输入电阻和输出电阻的影响。电路中引入负反馈，即闭环增益仅决定于反馈网络，因此闭环增益稳定。使放大电路的闭环电压特性曲线变平缓，线性范围展宽。通频带上下限频率得以扩展，扩大了带宽。只需画出输入回路的连接方式，即可知串联负反馈使输入电阻增大。本文将给出负反馈对提高放大电路的稳定性、抑制非线性失真、拓展带宽,改变输入/输出电阻的仿真结果。90901

毕业论文关键词：负反馈， 三极管，放大倍数，通频带，负载

Abstract: Negative feedback amplifier circuit simulation is an important part of the course, the negative feedback circuit gain at the expense of the cost, can improve amplification performance of the circuit, so the negative feedback amplifier circuit to explore a lot of sense。 This paper uses Multisim software to simulate the negative feedback amplifier circuit, both to deepen the understanding of the theory, but also improve the practical ability, but also to obtain better data analysis of the feedback circuit on the stability of the amplifier gain, reduce the nonlinear distortion, , Changing the input resistance and the output resistance。 Negative feedback is introduced in the circuit, ie the closed-loop gain is determined only by the feedback network, so the closed-loop gain is stable。 Of the amplifier circuit of the closed-loop voltage characteristic curve flattening, broadening the range of linearity。 The upper and lower frequencies of the passband are expanded to increase the bandwidth。 Simply draw input circuit connections, known series negative feedback to the input resistance increases。 This article presents the simulation results of a negative feedback amplifier circuit to improve the stability, suppressing nonlinear distortion, expansion of bandwidth to change the input / output resistance。 

Key words: Negative feedback，Triode，Magnification，Passband，Load

目   录

1 前言 4

1。1 背景 4

1。2 国内外分析现状 4

1。3 课题分析研究的主要内容及意义 4

2 负反馈的理论知识 5

2。1 基本概念 5

2。2 负反馈对放大电路的性能影响 8

3 负反馈放大电路的分析方法 12

3。1 微变等效分析法 12

3。2 方框图分析法 12

3。3 估算分析法 13

3。4 仿真分析法 13

3。5 实验分析法 14

4 实例进行仿真分析 14

4。1 负反馈电路设计参数要求和指标： 14

4。2 仿真分析的电路原理图 14

4。3 电路参数测试及分析 15

4。4 仿真测试分析数据表 25

结论 26

参考文献 27