线性调频信号，电磁波信号我要分享

中文说明：

线性调频信号是一种雷达常用的电磁波信号，当雷达信号检测到目标时候，反射后得到雷达回波信号。

English Description：

LFM signal is a common electromagnetic wave signal used by radar. When the radar signal detects the target, it is reflected to obtain the radar echo signal