ATmega128射频前端电路中锁相环频率合成器的研究.docVIP

ATmega128射频前端电路中锁相环频率合成器的研究 摘要社会信息化进程的发展，促进了世界范围内无线电业务需求的迅速增长，无线电业务的迅猛发展对频谱资源的需求与日俱增，电磁频谱供需日益紧张和电磁环境日益复杂的矛盾越来越尖锐，频谱资源短缺是当今无线电业务面临的重大问题。本介绍了一种采用锁相环技术(PLL) 设计产生高稳定度正弦信号的锁相环频率合成器方案，在该系统中采用锁相环频率合成器芯片ADF4360-7设计锁相环电路。详细分析了该芯片的工作原理，并给出了频率合成器的电路参数。通过该系统实现的本地振荡器信号的输出频率范围达到950MHz-1050MHz，且通过单片机ATmega128控制本振芯片实现了频率合成器每隔2MHz一个频率跳频输出。设计的该频率合成器可以应用于不同频段的射频前端的发射机和接收机系统。12373 关键字锁相环单片机本地振荡器PLL 毕业设计说明书（论文）中文摘要毕业设计说明书（论文）外文摘要 TitlePhase-locked frequency synthesizer in the RF front-end circuit Abstract With the process of the social informatization, the needs of wireless activity grow rapidly in worldwide. The rapid development of wireless activity and the increasing demand for spectrum resources make sharp contradiction between the supply and demand of the electromagnetic spectrum. And as electromagnetic environment become increasingly complex, the shortage of spectrum resource turns out to be the major issues facing the radio business today. This thesis describes a plan using phase-locked loop (PLL) to produce high stability sine signal phase-locked loop frequency synthesizer, in which the PLL frequency synthesizer chip ADF4360-7 is used to designed phase-locked loop circuit. The thesis also detailed analyzes the work principle of the chip and gives the parameters of the frequency synthesizer circuit. The system enables the local oscillator signal output frequency range to reach 950MHz-1050MHz. And through the control on the local oscillator chip by microcontroller ATmega128, the frequency synthesizer realizes a hopping output every 2MHz. The design of the frequency synthesizer can be applied in RF front-end transmitter of different frequency bands and receiver system. 结论44 致谢45 参 考 文 献46 附录A：基于单片机ATmega128普通I/O口的本振跳频源控制程序47 表1:本振寄存器参数设置表52 图一：系统实物图53 1 绪论 1.1研究背景及意义 在无线通信领域中, 高性能频率源是通信设备、雷达、电子侦察和对抗设备、精密测量仪器的核心部件。现代通信系统对频率源的精度、分辨率、转换时间及频谱纯度等提出了越来越高的要求, 性能卓越的频率源均通过频率合成技术来实现。同时电子干扰使雷达，通信面临着新的挑战。抗干扰要求雷达具有宽频带自适应捷变频能力，这就要求雷达装备频带宽，频率捷变速度快（与脉冲调频速度相适应）的高质量频率合成器。通信在电子战中为了获得低截获频率和高的