An orthomode coupler for an antenna system, particularly for a multi-feed antenna is provided. The orthomode coupler includes a first signal waveguide for a first RF signal that can propagate in the first signal waveguide, along a first axis, as well as a second signal waveguide for a second RF signal that can propagate in the second signal waveguide, along a second axis, where the second axis is disposed parallel to the first axis. Furthermore, the orthomode coupler includes a septum polarizer in which the first and second signal waveguide end, and a common signal waveguide having a third axis, along which a transmission and reception signal can propagate, where the third axis runs parallel to the first and the second axis, and where the common signal waveguide is coupled with the septum polarizer. The common signal waveguide includes a further polarizer.