A device for monitoring a health parameter of a person is disclosed. The device includes a device body, a radio frequency (RF) front-end connected to the device body and including a semiconductor substrate and an antenna array including at least one transmit antenna configured to transmit radio waves below the skin surface of a person and 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, wherein the semiconductor substrate includes circuits configured to generate signals in response to the received radio waves, and an alignment feature integrated into the device body and configured to align the antenna array with an object.
