Digital Beamforming Injection-Locked Wi-Fi Radar for Tracking Human Subjects and Their Respiration

This study presents the integration of an injection-locked Wi-Fi radar with a digital beamforming (DBF) phased array to extract angular and respiratory information from human subjects. The system transmits received Wi-Fi signals from the ambient Access Point (AP) to illuminate the subjects and then captures the echo signal using a uniform linear array (ULA) consisting of 4 receive (Rx) antennas. Four sets of injection-locked quadrature receivers (ILQRs) are employed to demodulate the Doppler information and identify the azimuth and respiration rates of subjects through the DBF technique.