It is provided an aperture coupled patch antenna comprising a substrate comprising a planar electrically conductive ground plane, an electrically conductive box arranged on and electrically connected to the ground plane to form an air filled cavity between the box and the ground plane, the box comprising an aperture in the form of at least one elongate slot. The antenna further comprises an electrically conductive patch arranged in parallel with the ground plane and at a distance from the box such that the aperture of the box is located between the patch and the ground plane and a distribution network comprising at least one elongate distribution element arranged in parallel with the ground plane between the ground plane and the patch, at a distance from the substrate and the ground plane and at a distance from the box such that a gap is formed between the distribution element and the box, wherein the extension of the distribution element intersects the extension of the aperture.