An antenna system for an airborne radar system with a dorsal unit having two opposing long sides extending in a height direction (Z) and a longitudinal direction (X), and two opposing short sides extending in a lateral direction (Y) and the height direction (Z), and an upper side opposing a bottom side each extending in the longitudinal direction (X) and the lateral direction (Y). The antenna system comprises antenna devices being interspaced and mounted in connection to one of the short sides or both the short sides and extending in the height direction (Z). Each of the antenna devices comprises a waveguide board.