电压控制LC振荡2器.doc

电压控制LC振荡器（A题） 摘要 电压控制LC振荡器采用变容二极管MV2105实现电压控制LC振荡，核心控制电路基于FPGA设计。系统主要由压控式LC振荡电路，锁相环，AGC电路，集成在单片FPGA芯片的控制电路及频率计，电压峰峰值测量电路，液晶显示模块，键盘等部分组成。通过晶体振荡器，MC1648和MC145152等构成的锁相环频率合成电路来提高输出频率的稳定度，实现100kHz频率步进；末级功率放大器采用三极管3DA5109，使其工作在丙类，以提高效率。若负载为容性阻抗，采用串联谐振回路以提高输出功率。为保证输出电压幅度稳定，加入交流电压负反馈和直流AGC电路。系统集成度高，稳定性、可靠性强。 关键词：压控LC振荡器，数字锁相环路，功率放大器，现场可编程逻辑门阵列 Abstract Varactor diode MV2105 is adopted to implement the voltage control LC oscillator. The core controller is designed base on FPGA. The system is made up of Voltage Control LC Oscillator, Phase Locked Loop, AGC circuit, FPGA integrated controller and cymometer, peak to peak voltage value measure circuit, LCD module and keyboard. By adding a PLL with crystal oscillator, VCO IC MC1648 and PD IC MC145152 as its main components, the stability of its output frequency is improved, and 100kHz frequency step is accomplished. Triode 3DA5109 is adopted to the Power amplifier and is set to work in class C amplification to get high efficiency. AC voltage inverse feedback and AGC is used to getting stable output amplitude. The system is a highly integrated one and it is characteristic of its high stability and reliability. Keywords：Voltage Controlled LC scillator , Digital PLL, Power Amplifier，FPGA 最后修改：September 18, 2003 目录 第一章 系统设计 …………………………………………………3 1.1 设计任务与基本要求 …………………………………………………………...3 1.2方案比较与论证 …………………………………………………………………3 1.2.1振荡电路方案选择 ………………………………….……………………3 1.2.2锁相环频率合成方案 ……………………………….……………………4 1.2.3 控制电路设计方案 ………………………………………………………5 1.2.4 频率测量方案 ……………………………………………………………5 1.2.5电源方案 …………………………………………………….……………5 1.2.6 显示方案 …………………………………………………………………5 1.3系统整体设计 ……………………………………….……………….…………6 第二章 单元电路设计 ……………………………………………6 2.1锁相环频率合成电路设计 …………………………………………..…….……6 2.1.1 压控振荡器电路设计 ………………………………..…………………6 2.1.2 鉴相器电路设计 …………………………………………………..……8 2.1.3 低通滤波器设计 ……………………………...………………………...11 2.2 输出电压峰－峰值测量电路设计 …………………………...…………..….…11 2.3频率测量电路设计 ………………………………………………………...…..12 2.4功率放大器设计 ……………………………………………...…………..……12 2.5稳压电源设计 ……………