基于DDS技术的LFM信号产生与FPGA实现

LFM Signal Generation and FPGA Implementation Based on DDS Technology

摘要:

分析了线性调频（LFM）信号的时频特性,分析了基于直接数字频率合成器（DDS）技术的信号产生原理，在此基础上，选择ALTERA公司的Cyclone II系列的FPGA芯片EP2C70F896C6FPGA，采用 ROM 查找表技术，基于QUARTUSII系统提供的 PLL 锁相环IP核设计系统时钟，设计产生带宽B=10MHz，时宽 的LFM信号。通过调用Modelsim仿真工具进行RTL仿真验证，FPGA电路仿真的结果与MATLAB仿真结果相符。

Abstract:

Absrtact- The time-frequency characteristics of LFM signal were analyzed, and the principle of signal generation based on direct digital frequency synthesizer (DDS) technology was analyzed. On this basis, EP2C70F896C6 FPGA chip of Cyclone II series of ALTERA company was selected, and the PLL phase-locked loop IP core provided by QUARTUSII system was adopted with ROM lookup table technology. The system clock was designed and the LFM signal with bandwidth B=10MHz and time-width was generated. RTL simulation was carried out by calling Modelsim simulation tool. The simulation results of the circuit of the FPGA are consistent with those of the simulation results of the MATLAB.