Ignition unit and system

An ignition unit adapted to produce an ignition in a combustion chamber of a combustion engine, the ignition unit comprising:

• a signal input connection;
• a radiofrequency resonator adapted to radiate a plasma-creating radiofrequency field into the combustion chamber;
• and
• a microwave resonator adapted to radiate a plasma-boosting microwave field into the combustion chamber, the microwave resonator comprising an output surface to which the combustion chamber is exposed when the ignition unit is fitted on the combustion engine,
• wherein the radiofrequency resonator comprises:
• an electrode that is at least partially embedded in the microwave resonator;
• and
• a winding that couples the signal input connection to the electrode, the winding being surrounded by a cylindrical tube, the winding being adapted to form a microwave transmission path between the signal input connection and the microwave resonator, the microwave transmission path being formed by one of the two following volumes:
• an outer volume between the winding and the cylindrical tube, and an inner volume of the winding.