基于DDS的SAR点目标回波模拟源的设计与实现

合成孔径雷达(SAR)模拟技术在SAR的研究和系统研制工作中具有十分重要的作用.设计并实现了基于直接数字合成技术(DDS)的SAR系统点目标回波模拟源,该模拟源主要包括ARM控制单元和DDS线性调频信号源两个部分.由ARM控制单元根据点目标回波信号模型计算得到多普勒相位值、方位幅度加权值等参数,控制线性调频信号的相位和幅度,直接产生模拟的回波信号.实验结果表明,该模拟信号源电路工作正确可靠,能满足SAR系统设计要求.

Design and Realization of SAR Point Target Echo Simulator Based on DDS

The SAR simulator has important effect on synthetic aperture radar system.A SAR point target echo simulator which based on DDS chirp signal generator is introduced;it is composed of ARM controller unit and LFM signal generator unit.First, we evaluate the echo number in a synthetic aperture by the synthetic time and PRF,then we get the Doppler phase and azimuth amplitude weight values according to the point target echo model,and control the phase and amplitude of the chirp signal,output the simulative signal directly.The experiment results on the hardware circuit prove that this method is efficient and meets the SAR system requirements very well.