A system for monitoring a health parameter in a person is disclosed. The system includes a frequency synthesizer configured to generate radio waves across a range of stepped frequencies, at least one transmit antenna configured to transmit the radio waves below the skin surface of a person, a two-dimensional array of receive antennas configured to receive radio waves, the received radio waves including a reflected portion of the transmitted radio waves, processing circuits configured to output data that includes amplitude and phase data in response to the received radio waves, and means for deriving data from at least one of the amplitude and phase data and determining a value that is indicative of a health parameter in the person in response to the derived data.
