电压控制LC振荡器

文档编号:ZD838    文档字数:12189,页数:27

摘要
 在LC振荡器的LC回路中，使用电压控制电容器（变容器），就可以在一定频率范围内构成电调谐振荡器。即电压控制LC振荡器。压控振荡器可广泛使用于频率调制器，锁相环路，以及无线电发射机和接收机中。
 系统主要采用MC145152、MC1648和预置双模分频器B571集成芯片为核心，由单片机89C52以及CPLD控制模块、键盘输入模块、液晶显示模块、可编程压控增益放大器模块、输出功率放大模块和振荡器输出电平指示模块构成。本系统的VCO部分采用了大变化范围的变容二极管做振荡电容，频率调节范围宽，在输入电压从0.5V变化到8V时，输出频率可以从14MHz变化到39MHz，且能保持良好的线性度，振荡环路加入了防振措施，高次谐波能得到很好的抑制，输出的正弦波波形良好，纯度高，失真低，幅度高且稳定。由于采用了数字锁相技术，使VCO的频率稳定度和精度极高，步进值可以在1KHz到1MHz内任意设置（最小为1KHz），为了实际使用方便和考虑到题目要求，本设计的步进值置为100KHz。。
 
 
 关键词 压控振荡器；数字锁相环；单片机嵌入式系统；高频功率放器

Abstract
This voltage control LC oscillator system controls the oscillator including the pressure (VCO), the digital phase-lock link (PLL), the monolithic integrated circuit (MCU) inserts the type system, high frequency power amplifier (RFAMP).
The system mainly uses MC145152, MC1648 and the initialization double model frequency divider B571 integration chip is a core, by monolithic integrated circuit 89C52 as well as the CPLD control module, the keyboard entry module, the liquid crystal display module, the programmable pressure controls the gain amplifier module, the output enlargement module and the oscillator power output instruction module constitution. This system VCO part used the sweeping change scope varactor to do vibrates the electric capacity, the frequency control scope is wide, when the input voltage changed from 0.5V to 8V, the output frequency may from 14MHz change to 39MHz, also could maintain the good linearity, vibrated the ring circuit to join the antivibration measure, the higher harmonic could be under the very good suppression, the output sine wave profile is good, the purity was high, distorts lowly, the scope was high also is stable. Because has used the numeral phase lock technique, causes VCO the frequency stability and the precision is extremely high, step-by-steps the value to be possible to establish (slightly in 1KHz to 1MHz in is willfully 1KHz), in order to the actual easy to operate and considered the topic request, this design step-by-steps the value to set is 100KHz.。

Keywords：The pressure controls the oscillator; Digital phase-locked loop; Monolithic integrated circuit embedded system; The high frequency power puts 
目 录
摘要……………………………………………………………………………………………………I
Abstract……………………………………………………………………………………………II
第1章  前言…………………………………………………………………………………………1
 1.1  课题的背景和意义…………………………………………………………………………1
 1.2  国内外压控振荡器的现状和发展…………………………………………………………1
第2章  总体方案设计……………………………………………………………………………4
 2.1  LC压控振荡器电路的选择…………………………………………………………………4
 2.2  高频功率放大电路的选择…………………………………………………………………5
 2.3  频率控制方式的选择………………………………………………………………………6
第3章  系统设计…………………………………………………………………………………9
 3.1  总体设计……………………………………………………………………………………9
 3.2  各模块设计及参数计算……………………………………………………………………10
 3.3  软件部分的设计……………………………………………………………………………18
第4章  系统调试…………………………………………………………………………………20
 4.1  单片机最小系统的调试……………………………………………………………………20
 4.2  压控振荡器模块的调试……………………………………………………………………20
 4.3  功率放大模块调试  ………………………………………………………………………21
第5章  指标测试…………………………………………………………………………………22
 5.1  测试仪器……………………………………………………………………………………22
 5.2  指标测试……………………………………………………………………………………22
 5.3  数据分析说明………………………………………………………………………………22
第6章  结论………………………………………………………………………………………23
致谢……………………………………………………………………………………………………25
参考文献………………………………………………………………………………………………26

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