User equipment with an integrated antenna system for radiating and sensing millimeter-waves

A method performed by a user equipment, the user equipment including a housing, millimeter-wave circuitry, a display disposed within a display layer across a primary plane defining a front surface of the user equipment, and one or more multi-layer loop antennas disposed behind the display layer across the primary plane, at least one of the multi-layer loop antennas having layers separated by a dielectric material and comprising a bottom layer including a first planar electrically-conductive structure in a first horizontal plane, the first planar electrically-conductive structure having a first edge region and a second edge region that is opposite the first edge region, an intermediate layer including second and third planar electrically-conductive structures sharing a second horizontal plane, the second and third planar electrically-conductive structures separated by a first gap in the second horizontal plane, and a top layer including fourth and fifth planar electrically-conductive structures sharing a third horizontal plane, the fourth and fifth planar electrically-conductive structures separated by a second gap in the third horizontal plane, the second gap configured to act as a loading capacitor of the multi-layer loop antenna, the method comprising:

• activating millimeter-wave circuitry to cause one of the one or more multi-layer loop antennas to radiate millimeter-waves within a spatial region over the display;
• sensing, through another one of the one or more multi-layer loop antennas, a reflection of the millimeter-waves;
• detecting, using the sensed reflection of the millimeter-waves, a reflection of an object within the spatial region, the detected reflection of the object representing a gesture performed by the object within the spatial region;
• determining, using the detected reflection of the object within the spatial region, the gesture performed by the object within the spatial region;
• and
• providing, to an application, the determined gesture.