应用于汽车FMCW雷达的超前进位锁相环研究

Research on Carry-Lookahead Phase Loop Applied to Automotive FMCW Radar

近年来汽车FMCW雷达广泛应用于新能源及智能网联领域,来测量外部目标的相对间距和速度。针对当前FMCW雷达系统灵敏度差、缺少灵活性、测量范围窄的问题,设计了一种应用于FMCW雷达领域的超前进位全数字锁相环。根据雷达对物体距离和速度的测量原理,采取集成电路芯片技术实现了对该环路结构的设计,利用Matlab软件搭建环路系统Z域模型并进行了稳定性分析对比,通过硬件描述语言(VHDL)编写环路程序,并联合调用Modelsim软件完成了仿真试验,最后结合仿真结果在硬件上验证设计的准确性。实验结果表明,基于超前进位的全数字锁相环有效提高了锁相频率,降低了系统延时,大幅度拓展了调频范围。

In recent years,automotive FMCW radar has been widely used in new energy and intelligent networking fields to measure the measure the relative distance and speed of external targets.Aiming at the problems of poor sensitivity,lack of flexibility and narrow measurement range of the current FMCW radar system,a Carry-Lookahead All-Digital Phase-Locked Loop applied in the field of FMCW radar is designed.According to the measurement principle of the distance and velocity of objects by radar,the design of the loop structure is realized by using integrated circuit chip technology.The Z-domain model of the loop system is built by Matlab software and stability analysis and comparison are carried out.The loop program is written by hardware description language(VHDL)and simulated with Modelsim software.Combine the simulation results to verify the accuracy of the design in hardware.The experimental results show that the ADPLL based on carry-lookahead can effectively increase the phase-locking frequency,reduce the system delay,and greatly expand the frequency modulatiohn range.