The invention relates to a multifilar helix antenna (1) comprising a wave feed and polarizing section (2) comprising a cover portion (3) comprising a through opening (4). The antenna (1) comprises a helix radiator (5) comprising three or more resonant helical elements (6) evenly distributed about an imaginary circle. Each helical element (6) extends in a longitudinal direction (Z) from the feed and polarizing section (2) through the opening (4) in the cover portion (3) and wound to form the helix radiator (5). Each helical element (6) comprises one or a plurality of wave perturbations (7) separated in the longitudinal direction (Z) and that each set of perturbations are positioned at the same level in the longitudinal direction (Z) to yield an equivalent array of stacked helical radiators, wherein the cover portion (3) comprises a rotationally symmetric corrugated assembly (8).