A radio antenna device for a radio communication terminal, e.g. a mobile
telephone, comprising a flat ground plane and an antenna element having a
radio signal feeding point disposed at the ground plane. The antenna
element has a folded three dimensional box-like shape. The inventive
antenna design provides for an antenna device with compact size, which at
the same time is operable in UWB (Ultra Wideband) frequency regions. The
antenna device may therefore advantageously be incorporated into a
portable communication terminal such as a mobile telephone.