基于AD9910的宽带LFM信号源设计

The design of a broadband LFM signal source based on AD9910

介绍了采用DDS激励PLL技术的宽带线性调频信号源的设计与实现,给出了主要的硬件电路和软件设计方案。由FPGA控制DDS芯片AD9910产生带宽可变的线性调频信号,采用DDS激励PLL的锁相倍频技术将信号倍频到4GHz。实验表明,基于该方案设计的线性调频信号源具有较高的频率分辨率和频率精确度,所产生的线性调频信号频谱干净稳定,满足雷达系统应用的要求。

This paper introduces the designing of LFM signal source which uses DDS spur PLL technology. The main scheme of hardware circuit and software design is introduced. We use FPGA to control DDS chip AD9910 to generate linear frequency modulated signal with variable band, use DDS spur PLL technology to multiple the signal＇s frequency to 4 GHz. Experiment shows that the LFM signal source based on this scheme has the characteristics of super fine frequency resolution, high frequency accuracy and the frequency spectrum of the LFM signal is pure and stable, so it can satisfy the need of the RADAR system.