基于高速DA转换的雷达中频信号产生方法

摘要

提出一种基于高速DA转换的雷达中频信号产生方法。该方法将常见的雷达信号，如常规脉冲、线性调频、二相编码等用同一表达式表示，通过设置不同的控制字组合来产生不同的信号。为节省硬件资源，研究了正弦表深度的确定方法，并提出仅采用前1/4周期正弦表产生雷达信号的方法。实验采用NIOS II软核计算正弦表、接收上位机计算的雷达信号参数，同时配置相位计算器中各控制字寄存器。硬件电路根据控制字产生相应的雷达中频信号。利用本方法还可产生频率编码、多相编码、滑变频、调幅等信号。%A new method for generating the radar intermediate frequency signal based on high-speed DA converter is proposed. In this method,the ordinary radar signals,such as common pulse, chirp,bi-phase code,are expressed as a uniform equation. The signal type and parameter are decided by control words. In order to save resource,the sine table depth is studied and the signal generation method which only use former 1/4 period sine table is proposed. In the experiment,NIOS II soft-core processor is used to compute sine table,receive the parameters of radar signal form PC computer,and configure the control word registers of phase calculator. The radar intermediate frequency signal is generated by the hardware circuit according to the control words. In addition,this method can be used to generate special signal such as frequency coding,poly-phase encoding,slip frequency,and amplitude modulation.