基于DDS的高码速率遥感卫星模拟信号频综源设计与实现

Research and Implementation of High Speed Remote Sensing Satellites Simulator Signal Source Based on FPGA and DDS Devices

研究将新型直接频率合成器DDS应用于遥感卫星模拟信号源。介绍了DDS的关键技术平和DDS原理；采用新型器件设计实现了一种基于FPGA＋DDS架构的高码速率卫星信号频综源，有效抑制了谐波杂散和噪声，具有48bit频率调整字（FTW），能以每步间隔不大于4μHz合成频率；给出了信号实测波形；该系统具有频率分辨率高、码速率高、频带宽（0．01-400MHz）、切换速度快等优点。

A new kind of direct digital synthesizer device is applied in the system of remote sensing satellites simulator signal source. Key technologies and principle of DDS are introduced; A high speed signal source based on FPGA＋new DDS devices is designed. It can restrain harmonic spurious effectively. The signal source provides precise and wide range of frequency, which is synthesized by frequency tuning word（FTW） in step sizes no larger than 4 μHz. Finally, some actually signal waves are plesented, which are prohed on the output pins of AD9912.