A portable communication device comprises a first set of layers providing different circuits, and a second set of layers comprising an antenna layer including all antennas and a grounding layer for all antennas. The grounding layer comprises an AMC material structure facing the antenna layer. The antennas are grouped according to operational frequency range, where each group covers a separate frequency range. The AMC material structure is also divided into sections, where each section faces a group of antennas and has a high surface impedance for the frequency range of this group. There is also a casing surrounding elements of the device including the antenna and grounding layer, where one side of the casing is provided with a strip of AMC material having a high surface impedance for an operational frequency range of at least one antenna.