Accuracy of A Low-Power Ka-Band Non-Contact Heartbeat Detector Measured from Four Sides of A Human Body

A Ka-band heartbeat detector using double-sideband transmission to detect human heartbeat and respiration signals is demonstrated. The short wavelength at Ka-band increases the sensitivity to detect small body motion. The double sideband transmission simplifies the radio transceiver architecture. The detection accuracy was calculated and compared for measurements using two different transmitting power levels, four different body orientations, and at five different distances. It was found that this detector achieved better than 80% detection accuracy for all the above conditions. The measurement results show that the higher power level (350-muAV) can achieve better detection accuracy and longer detection distance than lower power (14.2-muW). The results also show that the detection accuracy measured from the back is the best, which is analyzed and explained using a nonlinear model