An apparatus comprising: a ground member configured to receive one or more antennas, the one or more antennas being configured to operate in at least a first operational resonant frequency band; and a cover defining an exterior surface of the apparatus and including a conductive cover portion, the conductive cover portion being coupled to the ground member via a first reactive component to form a first resonant circuit configured to resonate at least partially in the first operational resonant frequency band, and via at least a second reactive component to form at least a second resonant circuit configured to resonate at least partially in at least the first operational resonant frequency band.