Characterization and performance of the Planck-LFI Flight Model Passive components

The LFI instrument, onboard the PLANCK satellite, consists of 22 pseudo-correlation radiometers. They are composed of a Front End Unit working at 20K and a Back End Unit working at 300K. The passive components of these radiometers are the Feed Horns, collecting the radiation from the sky, the Ortho Mode Transducers that split the incoming radiation into two perpendicular linearly polarized signals, and the waveguides that connect the Front End to the Back End Unit. In this work we describe their characterization.