US Patent 12061284 Microwave biometric authentication using machine learning

The technology described in this document can be embodied in a method for identifying a user of secured system. The method includes transmitting, using a first transceiver in an array of multiple transceivers, a first electromagnetic signal in the microwave range. An electromagnetic signal representing a first response of a portion of a subject to the first electromagnetic signal is received, by at least one transceiver of the array of multiple transceivers. The subject is identified based at least in part on one or more parameters of the first response.