The present disclosure relates to a plug-in antenna device arranged to be received in a waveguide section. The plug-in antenna device includes one or more dielectric elements arranged in series and spaced apart by connecting members, a top-most dielectric element being arranged as antenna element. When the plug-in antenna device is received in the waveguide section, the dielectric elements are arranged electromagnetically coupled, whereby a radio frequency signal included in a radio frequency band passing to or from the antenna element via the dielectric elements is arranged to be electromagnetically filtered.