Removable smartphone case for radio wave based health monitoring that generates alignment signals

A removable smartphone case comprising:

• a semiconductor substrate;
• an antenna array including at least one transmit antenna connected to the semiconductor substrate and configured to transmit radio waves below the skin surface of a person and a two-dimensional array of receive antennas connected to the semiconductor substrate and 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 that correspond to an alignment of the antenna array relative to a vein in the person in response to the received radio waves;
• and
• a communications interface configured to transmit digital data that corresponds to the signals generated by the semiconductor substrate from the removable smartphone case.

A removable smartphone case comprising:

• a case body configured to receive a smartphone;
• a radio frequency (RF) front-end connected to the case 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
• a processor configured to determine an alignment of the antenna array relative to the vein in the person in response to the generated signals;
• and
• means for outputting a signal that is indicative of the determined alignment of the antenna array relative to the vein.