中文摘要：

线性调频步进信号的距离高分辨能力为目标的精细微多普勒特征提取奠定了基础，因而研究该信号体制雷达的微多普勒效应具有重要意义。在阐述线性调频步进信号成像原理的基础上，研究了线性调频步进信号体制下雷达目标微多普勒效应的产生原理，分析了距离像走动和卷绕的产生原因，并通过重点分析旋转和振动形式的微动引起的微多普勒效应，比较了其与线性调频信号体制下微多普勒效应的异同，得出了在满足距离像不卷绕条件下目标微动参数与谱图上正弦曲线参数之间的关系，为后续的微多普勒特征提取工作提供了理论基础。仿真计算验证了本文微多普勒效应理论分析的正确性。

英文摘要：

The micro -Doppler （m- D） effect provides a new approach for auto radar target recognition. The frequency - stepped chirp signal makes the fine m - D signatures extraction of target possible because of its high range - resolution capability. Based on the expatiation of the imaging principle of the frequency - stepped chirp signal, the principle of generating the m - D effects in the signal is studied, and the causations of the range profileg migration and wrapping are analyzed. The similarities and differences of the m - D effects between the chirp signal and the frequency - stepped chirp signal are discussed based on the analysis of the m - D effects caused by the rotation and vibration. The relationship between the parameters of the micro - motion and of the sinusoids on the spectrogram is obtained when the range profile isnt wrapped. This provides the theoretical basis for the extraction of m - D signatures of radar target with micro - motion structures. The simulations experiments are given to verify the validity of the theoretical analyses.