Measurement of heart and breathing signals of human subjects through barriers with microwave life-detection systems

Two life-detection systems using electromagnetic waves, at X-band (10 GHz) and L-band (2 GHz), have been constructed to detect the breathing and heart signals of human subjects who are located behind barriers. The X-band system can penetrate a brick wall of up to about 1.5 ft, and the L-band system can detect the breathing and heart signals of a human subject buried under a pile of dry rubble up to 3-ft thick.<>