基于AD9858的宽带雷达信号源设计与实现

摘要

A design scheme of a wideband radar signal source is given in the paper. It is composed of a baseband signal source and frequency multiplier chain. A linear FM signal is generated, whose center frequency is 1 GHz and bandwidth is 800 MHz. The baseband signal source selects high-performance digital frequency synthesizer chip AD9858 produced by AD, and DDS control word is loaded by FPGA to generate (200?0)MHz baseband signal. Multiplier chain is used to carry out up-conversion and fre-quency doubling of the baseband signal so as to output wideband radar signal whose bandwidth is 1 GHz+400 MHz. The wide-band radar signals are tested through the oscilloscope and spectrum analyzer, and meet the design requirements.%给出一套宽带雷达信号源的设计方案,它由基带信号源和倍频链组成,产生中心频率为1 GHZ,带宽为800 MHZ的线性调频信号.基带信号源选用了AD公司高性能数字频率合成芯片AD9858,由FPGA实现加载DDS控制字,产生(200±50) MHz的基带信号 .倍频链将基带信号进行上变频和倍频,可输出1GHz±400 MHz的宽带雷达信号.经示波器和频谱仪测试显示,所设计的宽带雷达信号源满足设计要求.