变容二极管调频电路课程设计

目录

摘要………………………………………………………………………………………

1题目分析…………………………………………………………………………

2系统方案论证………………………………………………………………………

2.1 电路设计原理………………………………………………………………………

2.2 电路的设计方案…………………………………………………

2.3 电路设计……………………………………………………………………………

2.4 主振电路设计原理分析……………………………………………………………

2.5 变容二极管直接调频电路…………………………………………………………

2.6调频信号分析………………………………………………………………………

2.7 变容二极管频率调制的原理………………………………………………………3电路工作分析………………………………………………………………………

3.1 谐振回路总电容……………………………………………………………………

3.2 调制灵敏度………………………………………………………………

4.增加电路稳定度…………………………………………………………………

4.1 震荡回路参数LC…………………………………………………………

4.2温度补偿法……………………………………………………………………

4.3回路电阻………………………………………………………………………

4.4增加缓冲级………………………………………………………………

4.5有源器件参数………………………………………………………………

4.6高稳定度LC振荡电路………………………………………………………………

5. 电路元器件参数设置………………………………………………………………………

5.1 LC震荡电路直流参数设置…………………………………………………………

5.2 变容管调频电路参数设置…………………………………………………………

5.3 放大电路参数设置………………………………………………………………

5.4 调制信号的幅度计算………………………………………………

6. 元器件清单…………………………………………………………………

7. 电路调试…………………………………………………………………

8.课程答辩…………………………………………………………………

9.实验心得体会…………………………………………………………………

10.致谢…………………………………………………………………

11.参考文献…………………………………………………………………

摘要

With the increasing use of electronic and communications technology has progressed, various kinds of new electronic product development at an increasing rate.The modern computer technology and the microelectronic technology further union and the development caused the electronic circuit and the communication link appeared two branches. One is the movement toward a more highly integrated IC development: while the other is the use of discrete components and hardware description language for the new devices are specially designed.

The FM broadcast has the resistance to interference strongly, the sound clear and so on the merits, has obtained the fast development. The frequency modulation broadcasting station's frequency band probably is usually 200~250kHz, Its bandwidth is amplitude modulation broadcasting station's dozens of times, is advantageous for transmits the high fidelity stereo sound signal. Because the modulated wave receives the bandwidth the limit, has the pass band width and the disturbance contradiction in the receiver, therefore the tonic train signaling frequency limits in the 30~8000Hz scope. When frequency modulation, may expand the tonic train signaling frequency range to 30~15000Hz, causes the tonic train signaling the frequency spectrum component to be richer, the sound quality is greatly the enhancement.

随着电子与通信技术的不断进步，各种新兴电子产品的开发速度越来越快。现代计算机技术和微电子技术的进一步结合和发展使得电子电路和通信线路出现了二个分支。一个是朝着更高集成度的集成电路发展：而另一个是利用分立元件和硬件描述语言对新型器件进行专门设计。

调频广播具有抗干扰性能强、声音清晰等优点，获得了快速的发展。调频电台的频带通常大约是200～250kHz，其频带宽度是调幅电台的数十倍，便于传送高保真立体声信号。由于调幅波受到频带宽度的限制，在接收机中存在着通带宽度与干扰的矛盾，因此音频信号的频率局限于30～8000Hz的范围内。在调频时，可以将音频信号的频率范围扩大至30～15000Hz，使音频信号的频谱分量更为丰富，声音质量大为提高。

目前，应用最广泛的是采用变容二极管直接调频技术，即利用二极管反偏工作的PN 结呈现的势垒电容，它与回路中的电感共同构成振荡器的振荡回路，从而作为振荡频率直接调频电路。它具有工作频率高、固有损耗小和使用方便等优点。

变容二极管为特殊二极管的一种。当外加顺向偏压时，有大量电流产生，PN （正负极）接面的耗尽区变窄，电容变大，产生扩散电容效应；当外加反向偏压时，则会产生过渡电容效应。但因加顺向偏压时会有漏电流的产生，所以在应用