Ultra compact radiating element

A dual band antenna element having a main radiating direction, comprising:

• a first radiating element for use in a first frequency band;
• a first electrically closed ring for use in the first frequency band galvanically isolated from and arranged at a predetermined distance (D) from the first radiating element in the main radiating direction, wherein the first electrically closed ring at least partially overlaps the first radiating element in the main radiating direction;
• and
• a second radiating element for use in a second frequency band, wherein a center frequency of the second frequency band is higher than a center frequency of the first frequency band, wherein the second radiating element is arranged within a circumference of the first radiating element, wherein the second radiating element is arranged substantially at the predetermined distance (D) from the first radiating element in the radiation direction,
• wherein the first radiating element comprises four slots regularly arranged in a circular fashion every 90°, wherein each slot can be excited so that excitations are combined to obtain a certain polarization for a radio frequency (RF) signal radiated by the first radiating element.