3mm线性调频源线性度实时数字校正技术研究

Digital Real-time Correction Algorithm of Linearity for 3 mm Linear Frequency-modulated Source

该文理论推导了针对3mm波段线性调频连续波信号源高线性度的校正方法,提出了实时数字式闭环线性校正方案,解决了可编程逻辑器件(FPGA)实现中遇到的精度和时间变量2个关键问题,完成了VHDL语言的软件设计;通过计算机软件进行了基于FPGA的功能仿真。结果表明:该数字校正网络具有实现方便、校正后线性度高达0 .2 4‰和具有较好的实时处理能力的特点;

The correction algorithm of linearity is studied and a digital real-time closed-loop correction algorithm of linearity scheme is presented for a high linearity 3 mm LFMCW(Linear frequency-modulated continuous wave) signal source. The two key problems of the precision and the time variable,met in the solution with FPGA(Field programmable gate array), are solved; the VHDL software is designed and simulated with FPGA by computer. The results prove the feasibility of the correction algorithm with FPGA and show that: using this theme, the system is more simple, the linearity after correction algorithm of linearity arrives at 0.24 ‰ and the system is more real-time than those using traditional analog scheme.