A split open loop resonator antenna comprising a first electrically connected open loop structure which comprises a first slit, a second electrically connected open loop structure containing a second slit. The first electrically connected open loop structure contains a first main structure being a portion of a first open loop and a first additional structure being another portion of the first open loop. The second electrically connected open loop structure has a second main structure. The first main structure is arranged in a first plane. The first additional structure is arranged in a second plane different from the first plane. The plurality of planes are parallel to each other and the first main structure is electrically connected to the first additional structure. The first main structure and the first additional structure are arranged such that when projected in a same plane they cover first open loop shape.