The present disclosure refers to an antenna system vehicles, preferably for Vehicle-to-Everything (V2X) communications, comprising a planar reflector and a radiating element placed over the reflector, wherein the radiating element comprises segments, preferably straight segments, arranged to configure two connected quadrilateral frame antenna elements. Each quadrilateral frame antenna element having an inner pair of segments and an outer pair of segments, wherein the segments of the inner pairs are substantially parallel to the reflector, and the segments of the outer pairs are inclined with respect to the segments of the inner pairs. The segments of the outer pairs have one end connected with the reflector.