宽带视频放大电路的设计 毕业设计

论文编号:JD006  字数:13580.页数:29 

摘  要
本文主要是设计一个晶体管宽带视频放大电路,该电路由三个部分组成：带通滤波,前置级, 输出级。
本文应用M-FET电路研制宽带视放前置级电路。新设计的M-FET视放前级电路的特点是取消了电感补偿元件. 实验结果表明,该电路的频带宽度可扩展到6MHz，且其幅频特性曲线的平坦有较大的改善。因此，宽带视放前级电路可以取消电感补偿元件，更适于集成化。
视频放大器的频带要足够宽，特别是高清晰信号时，不够宽就会造成高频信号的失真，用简单的共射级RC放大器不能满足要求，对于末级视放，仍采用多种补偿措施。解决的方法有多种：加发射级电容；集电级加电感串联(并联)补偿等，结合使用M-FET放大电路可以更大增加带宽。
本文对M-FET放大电路做了详细的介召，对控制中存在的问题进行了说明，对计算公式做了精确的推导。对几种补偿电路做了简单的说明与分析。

关键词：宽带；频率补偿；视频放大，放大增益；输出幅度

 Abstract
The main body of a book be to design a transistor TV set video amplification circuit , be a circuit''s turn to be composed of three parts mainly: Belt wave filtering , preposition level, export level.
The M-FET circuit the main body of a book is applied develops a TV set look at put in the new circuit of final stage. That newly designed M-FET looks at the characteristic putting in the final stage circuit is to have canceled inductance compensating a component. The experiment bear fruit indicates 6MHz about expansion than the bandwidth gathering an electricity having back-off looking at of inductance to put in the final stage circuit step , owes a circuit, whose curvilinear amplitude-frequency characteristic evenness has bigger improvement at present therefore, the TV set is looked at putting in the final stage circuit being able to cancel inductance compensating a component , is is suitable for integration-rization more.
Television emission pulse because of it, the band having decided video frequency amplifier''s needs sufficient width, distortion insufficient width is only capable to do bringing about wave form, the amplifier can not satisfy a request , the method solving has with shooting RC on level simplely together various: Add launch level capacitance; Collection electricity level adds in-line (shunt compensation) of inductance , M-FET enlarges a circuit waiting to can increase bandwidth.
The main body of a book have enlarged a circuit to M-FET having made upright detailed Zhao , have carried out explanation on have problem controlling middle, choice and parametric ascertaining that of component have composed detailed instruction for compensating a component, has made accurate derivation to the formula secretly scheming against.

Keywords: Broadband; Frequency compensation; Video amplification; Enlarges gain; Output extent
目  录
摘  要 I
Abstract II
目录 II
图表目录 III
第一章　绪  论 1
1.1 引言 1
1.2 宽带视频技术的应用与发展 1
1.3 问题的提出 3
1.4 论文各章节的安排 3
第二章  视频放大器的分析与研究 4
2.1 视频放大器的分析方法 4
2.1.1 稳态分析法 4
2.1.2 瞬态分析法 4
2.2 对视频放大器的要求 4
2.2.1 电压增益要大 5
2.2.2 频带要足够宽 5
2.2.3相位失真和灰度失真要小 5
2.2.4 其它要求 5
第三章  视频放大器的前置级与输出级的设计 6
3.1 视频放大器的前置级(预视放) 6
3.2 M-FET 视放前级的电路的设计与实验 6
3.2.1 M-FET 电路的性能 7
3.3 视频放大输出级 7
第四章  多级放大器 12
4．1 阻容耦合电压放大器 12
4．2 共射-共基放大器 13
4．3直接耦合电压放大器 16
第五章  总结与展望 22
参考文献 23
致      谢 24