【作者】 赵峰波；

【导师】 赵国庆；

【作者基本信息】 西安电子科技大学 ， 电路与系统， 2001， 硕士

【摘要】 线性调频信号是通过线性频率调制获得大的时宽带宽积的一种脉冲压缩信号，具有大的带宽，因此有高的距离分辨力。现在的雷达基本上采用模拟系统产生线性调频信号，由于模拟系统在带宽变化方面和不同带宽间切换方面不如数字系统，本文采用DDS（Direct Digital Synthesis）技术产生不同带宽的线性调频信号以改善海洋卫星高度计在测量粗糙表面时存在的失锁现象。 本文详细介绍了以下几个方面：线性调频信号的波形、匹配滤波器、模糊函数、速度分辨力、距离分辨力及抗干扰能力；产生线性调频信号的几种方法并简要分析了各种方法的优缺点；DDS 的工作原理、性能指标，分析了相位截断产生的相位误差，并提出解决这种误差的新方案；设计了一个产生线性调频信号的具体电路。更多还原

【Abstract】 Chirp signal is a kind of pulse-compressed signal with large time-bandwidth products achieved through linear frequency modulation. It has high resolution in range because of its great bandwidth. The radar available basically adopts the analog system to produce chirp signal. Considering the fact that the analog system is not so good as the digital system on the respect of variation of bandwidths and on the respect of switch between different bandwidths. This paper proposes to adopt the DDS(Direct Digital Synthesis) technique that produces chirp signals of different bandwidths to improve the situation of losing tracks for the ocean satellite altitude indicator in measuring coarse surfaces.This paper gives a detailed account of the waveform, matched-filter, fuzzy function, resolution in speed, resolution in range and the capacity of anti-interference of the Chirp signal. It deals with several methods to produce chirp signal and the advantages and disadvantages of these methods. It describes the working principle and performance of DDS, analyses the phase errors initiated by the phase truncation and proposes a new scheme to solve the error. Finally, a specific circuit to produce chirp signal is designed in the paper.更多还原