Electromagnetic band-gap structure

An electromagnetic band gap structure is provided including a ground plane and a periodic planar arrangement of surface elements mounted parallel to and at a predetermined distance from the ground plane. Each of the surface elements is supported in the planar arrangement by at least one conducting support element extending from an edge of the surface element to the ground plane, avoiding back-to-back parallel support elements. This arrangement allows for the surface elements and their respective support elements to be folded from flat metal templates to greatly simplify manufacture. An antenna is also provided in which an antenna element is mounted in such a way as to use the electromagnetic band-gap structure as a ground plane. This allows for a low-profile antenna to be made as the antenna element may be mounted close to the plane of surface elements in the structure.