A New Tracking Modes Coupler using a Corrugated Feed for Satellite Communication Earth-Station Antenna

A corrugated tracking modes coupler operating with any linear or circular polarization is described. This device propagates without disturbance the received and transmitted HE11 communication modes, and selects as tracking modes, the TM01 and HE21 modes by use of their specific phase velocities which are equalized by the proper design of the corrugated guide geometry. The tracking modes are coupled by four arrays of transversal slots in four "collecting guides" having the same phase velocity. Experimental performances in the 10.95 - 14,5 GHz band are given. They show a very low parasitic coupling of the HE11 mode, no distortion of its primary radiation patterns and a good tracking sensitivity.