A radar antenna arrangement, in particular for motor vehicles, is presented, having of a longitudinal waveguide, into which electromagnetic waves are coupled in such a manner that they expand in the longitudinal direction (X) of the waveguide, and an interference structure (12) with a plurality of metallic sections, whereby the interference structure in proximity to the waveguide, at a distance from the waveguide in a first transverse direction (Y) to the waveguide, is arranged at least approximately parallel to the longitudinal direction (X) of the waveguide, so that the interference structure effects an adjusted radiation of the radar waves. The waveguide comprises in the longitudinal direction two metallic surfaces (31, 41) and between these, a dielectric medium (32, 42), whereby the surfaces (31, 41) run in a second transverse direction (Z), which stands both vertically to the first transverse direction (Y) and to the longitudinal direction (X) of the waveguide. Preferably, the interference structure (12) is designed as a rotatable drum with metallic sections which are changed on the circumference and a reflector arrangement is provided for bundling and polarizing the waves.