The Tesat approach is to be able to offer a family of TT&C transponders for different application scenarios. Further to the available S-Band transponder, a Ku-Band transponder has been qualified. Within the developments further operational modes will be implemented, which are contained within the TT&C standards, allowing systems to expand the functionality of the TT&C links. A Ka-Band Demonstrator incl. Spread Spectrum technology has been validated, whilst our universal S-Band TT&C Transponder has a flight heritage of up to 50 units and is suited for all kind of missions.