An antenna array assembly comprises a dielectric film (2) carrying an array of conductive patch radiator elements (7) and a plurality of conductive feed tracks and a ground plate (1), a face of the ground plate (1) having a contoured shape comprising a first part configured to be in contact with the dielectric film (2), and a second part comprising sunken sections with respect to the first part arranged to underlie the conductive feed tracks and conductive patch radiator elements (7), and the ground plate having locating protrusions (6g, 6f) protruding from the first part. The dielectric film is attached to the ground plate by location of holes in the dielectric film with the locating protrusions (6g, 6f) such that the dielectric film is held under tension to maintain spacing of the dielectric film (2) from the sunken sections of the ground plate (1) without the use of a dielectric spacer layer between the dielectric film (2) and the ground plate (1).