The present application discloses a beamforming antenna device and a method for operating a beamforming antenna device. The beamforming antenna device includes a plurality of antenna elements and a plurality of sub-arrays. The plurality of sub-arrays are coupled to the plurality of antenna elements. Each of the sub-arrays is coupled to its adjacent sub-arrays of the plurality of sub-arrays, and at least a portion of the plurality of sub-arrays form a sub-array chain.