Antenna for radar-based fill level measurement device

The invention relates to a compact and efficient antenna (11) for a fill level measuring device (1), in particular based on a radio frequency radar. To this end, the antenna (11) consists of: a mounting (110) having a dielectric-tight cavity (111); an input coupling structure (112) by means of which a radar signal (SHF) can be coupled into the cavity (111) along the main beam axis (a); and a lens (113) that refracts a radar signal (SHF). The lens seals the cavity (111) of the mount (110) in such a manner that the input coupling structure (112) is positioned in the focus of the lens (113) and the lens (113) is aligned in the main beam axis (a) of the input coupling structure (112). If the mount (110) or the lens (113) and the input coupling structure (112) are made up of two separate subassemblies (A, B), the antenna (11) can be manufactured with little expenditure. In this case, the two subassemblies (A, B) can be assembled along a defined joint seam (114) after production thereof, such that the cavity (111)