L波段数字扫频源的研制

【作者】 邱红兵；

【导师】 牟善祥；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2004， 硕士

【摘要】 目前设计高分辨率、低相位噪声、捷变频的频率合成器是国内外研究的热点。本文采用直接频率合成(DDS)和锁相环(PLL)相结合的频率合成技术，设计出L波段扫频源。 首先分析了DDS的原理、输出频谱的特性。指出了在实际工程设计中，需注意的问题。 接着对PLL的相位噪声和杂散进行分析，得出估算相位噪声和杂散性能的公式。并提出了从环路带宽和相位余量出发设计环路滤波器的方法。 最后，分析DDS和PLL相结合的扫频源的方案，利用其中的一种方案设计出L波段的扫频源。更多还原

【Abstract】 It is the research focuses to design frequency synthesizers with high frequency resolution, low phase noise and immediate settling to frequency hop. This dissertation focuses on the realization of L-band sweep signal source based on Direct Digital Synthesis (DDS) and Phase Locked Loop (PLL).Firstly, the structure and output spectrum of DDS is analyzed. The problems of practical design are also discussed in detail.Secondly, the phase noise and spurs of PLL are analyzed and the formulae for calculating them are given. The method of designing the loop filter with the phase margin and loop bandwidth is displayed.At last, several plans of sweep signal source with DDS and PLL together are discussed, based on one of them, the L-band sweep signal source is designed successfully.更多还原