COUPLING AND RE-RADIATING SYSTEM FOR MILLIMETER-WAVE ANTENNA

An antenna subsystem of a communication device has an open cavity including an inner opening and lateral and outer sides that define a cavity. The cavity is sized less than required for cavity mode resonance at a millimeter-wave operating frequency. A millimeter-wave antenna element placed at the inner opening of the hollowed section cavity excites evanescent electromagnetic fields in the cavity. A slot antenna is formed in a metallic layer of the outer side of the cavity. A metallic sectioned proximity post has a first section positioned adjacent to and spaced apart from the millimeter-wave antenna element to couple to, and conduct, the evanescent electromagnetic field. The metallic proximity post has a second section positioned adjacent to and spaced apart from the slot antenna to couple at the millimeter-wave operating frequency, enabling re-radiation by the slot antenna.