Radar device and method of detecting passenger on rear seat by using the same

A method of detecting a passenger on a rear seat by using a radar device, the method comprising:

• (a) transmitting a radar signal in a form of a multi-channel high-speed frequency-modulated continuous wave (FMCW) to a periphery of the rear seat and receiving a signal reflected from a target by a transceiver;
• (b) detecting a motion of the passenger through a macro speed detection scheme by a signal processor configured for processing the received signal;
• (c) detecting a change according to characteristics of the passenger through a micro speed detection scheme;
• and
• (d) determining, by a passenger detector, that the passenger is present on the rear seat when the motion or the change is detected in step (b) or step (c), detecting a distance to the target, a motion of the passenger, and a change rate according to characteristics of the passenger based on the processed signal, removing peripheral interference of a vehicle by limiting the detected distance to the target, and comparing the motion and the change rate, and
• wherein the micro speed detection scheme is for detecting the change caused by respiration of the passenger by using a repetition interval corresponding to a plurality of repetition intervals of a chirp signal which is used for the detection in the macro speed detection scheme.