基于FPGA的LFMCW测距雷达调制信号源设计

摘要

In order to improve the frequency modulation linearity of the front end of the LFMCW ranging radar, thus improving the precision of radar ranging, a scheme of modulation signal source for LFMCW ranging radar based on FPGA is designed. Implementation of hardware and software are accomplished. The FPGA acts as the control center of the modulation signal source, and the DA converter works as the main peripheral equipment. Digital waveform is generated by FPGA via VHDL program and analog signal is obtained through DA converter. After amplifying and filtering, the analog modulation voltage signal which is used to drive the front end of radar is output. The experimental results show that the modulation voltage source is flexible and can apply to drive a variety of radar front end for its stability and reliability.%为从信号源上提高LFMCW测距雷达前端发射信号的调频线性度，改善雷达测量精度，设计了一种基于FPGA的LFMCW测距雷达调制信号源，并完成了软硬件设计与实现。调制信号源以FPGA为控制核心，DA转换器为主要外围设备。编写VHDL语言编程产生数字调制波形，利用DA转换器转换为模拟信号，经过低通滤波器和放大器，输出驱动雷达前端的模拟调制电压信号。实验结果表明，该设计实现灵活，输出的调制电压信号波形稳定可靠，能够驱动多种雷达前端。