Separation of Multiple Closely Spaced Sources Using Frequency Sweep Single-Channel Continuous Wave Doppler Radar

Doppler radar physiological monitoring has recently been demonstrated effective in applications where multiple subjects may be present in the radar field of view. Most multiple subject monitoring methods reported to date rely on ranging with FMCW or UWB radar and direction of arrival techniques using antenna beam scanning or multiple antennas. This paper presents a frequency tuning-based approach for isolating signals from multiple sources by alternatively suppressing individual sources with a single channel, single antenna radar. This technique was demonstrated experimentally to separate signals from two closely spaced, nearly equidistant mechanical movers simulating human breathing.