宽带微多普勒雷达射频前端的设计与实现

Design and Implementation of RF Front End for Wideband MicroDoppler Radar

近年来雷达探测技术在各个领域迅猛发展,广泛应用于军事、民用等方面,生命体征雷达由于其非接触性、穿透性和便携性等优点而引发人们的关注。传统生命体征检测方式多采用接触式测量,不能满足一些特殊场景的应用,并且难以避免电极等设施对结果造成的影响,生命体征雷达可以有效弥补这些不足。本文设计了应用于WIFI6E频段的生命体征雷达的射频前端部分,实现对调频连续波的收发及中频处理。针对锁相环技术频率切换速度慢的缺点,发射端采用直接数字频率合成(DDS)技术+倍频+上变频的方案产生发射信号;接收端采用零中频接收机方案,减少镜像频率的干扰、降低设计的复杂度并减小其体积。经过对比分析得到较优的系统方案并进行了实物制作并测试。

In recent years, radar detection technology has developed rapidly in various fields and is widely used in military and civil fields. Vital sign radar has attracted people’s attention due to its advantages of non-contact, penetration and portability.Traditional vital sign detection methods mostly adopt contact measurement, which cannot meet the requirements of some special scenes, and it is difficult to avoid the influence of electrode and other facilities on the results. Vital sign radar can effectively make up for these deficiencies.In this paper, the RF front end of the vital signs radar applied in WIFI6 E band is designed to realize the transceiver and IF processing of FM continuous wave. Aiming at the slow frequency switching speed of phase-locked loop(PLL) technology, the transmitting signal is generated by the direct digital frequency synthesis(DDS) technology, frequency doubling and up-conversion scheme.The receiver adopts the scheme of zero IF receiver to reduce the interference of mirror frequency, reduce the complexity of design and reduce its volume. Through comparative analysis, the better system scheme was obtained and the actual production and test were carried out.