A device for monitoring a health parameter in a person is disclosed. The device includes a semiconductor substrate, at least one transmit antenna configured to transmit millimeter range radio waves over a 3D space below the skin surface of a person, multiple receive antennas configured to receive radio waves, the received radio waves including a reflected portion of the transmitted radio waves, wherein the semiconductor substrate includes circuits for processing signals received on the multiple receive antennas, wherein processing signals includes mixing signals of two different frequencies, and wherein the semiconductor substrate includes at least one output configured to output a signal that corresponds to a health parameter of a person in response to received radio waves.
