A low power 24 GHz radar system for occupancy monitoring

This paper presents a low power 24GHz Doppler radar system for presence detection and occupancy monitoring. It is based on a minimalistic hardware approach and is able to wirelessly sense human respiratory signals so that even non-moving persons can be detected. By intermittently measuring, the average power consumption could be significantly reduced down to e.g. 0.2mW for 20 measurements per second. Experiments verify that, due to the short wavelength, the single channel receiver limitations can be neglected when only a detection of human respiratory but no evaluation of the breathing frequency is necessary.