Automatic clutter-canceler for microwave life-detection systems

A microprocessor-controlled automatic clutter-cancellation subsystem, consisting of a programmable microwave attenuator and a programmable microwave phase-shifter controlled by a microprocessor-based control unit, has been developed for a microwave life-detection system (L-band 2 GHz or X-band 10 GHz). This system can remotely sense breathing and heartbeat movements of living subjects. This automatic clutter-cancellation subsystem improves manual clutter-cancellation in microwave systems. A series of experiments have been conducted to demonstrate the applicability of this microwave life-detection system for rescue purposes. The 2-GHz system performs well for remotely detecting human breathing and heartbeat signals through a pile of rubble of up to about three feet thick.<>