Embodiments of the invention include a microelectronic device that includes a first substrate having radio frequency (RF) components and a second substrate that is coupled to the first substrate. The second substrate includes a first conductive layer of an antenna unit for transmitting and receiving communications at a frequency of approximately 4 GHz or higher. A mold material is disposed on the first and second substrates. The mold material includes a first region that is positioned between the first conductive layer and a second conductive layer of the antenna unit with the mold material being a dielectric material to capacitively couple the first and second conductive layers of the antenna unit.