Antenna element and antenna device comprising such elements

An antenna device comprising a plurality of antenna elements including a first and second antenna element, each antenna element comprising an active patch formed by a conductive layer on a front surface of a substrate and a ground patch formed by a conductive layer on a back surface of the substrate, wherein for each antenna element:

• said active patch comprises a conductive area having at least one spiral slot in a central portion thereof and having conductive peripheral portions substantially surrounding the central portion, said conductive peripheral portions having a width substantially greater than a trace width (WT) of the spiral slot;
• a signal feed strip is formed by a part of said conductive layer extending from a side of said active patch across the front surface of the substrate;
• and
• at least one signal ground strip is formed adjacent to the signal feed strip on the front surface of the substrate and extends toward the active patch, but separated therefrom by a predetermined gap, such that the ground patch on the back surface is coupled parasitically to the active patch and said at least one signal ground strip;
• and
• wherein said first and second antenna element are spaced from one another in a direction, and wherein a spacing in said direction between the active patch of said first element and that of said second element is less than or equal to half the wavelength of the active patch of the first element.