Arrangement in microwave stoves

Claim 1

A MICROWAVE OVEN COMPRISING A WALL STRUCTURE DEFINING A HEATING CAVITY, AN OPENING IN ONE WALL OF SAID CAVITY FOR SUPPLYING MICROWAVE ENERGY THERETO, A MAGNETRON, A WAVEGUIDE INTERCONNECTING SAID MAGNETRON WITH SAID WALL OPENING, A REACTIVE MATCHING ELEMENT POSITIONED WITHIN SAID WAVEGUIDE BETWEEN THE MAGNETRON AND THE WALL OPENING, AND A FIELD STIRRER ROTATABLY MOUNTED IN SAID CAVITY IN FRONT OF AND CLOSE TO SAID WLL OPENING SO AS TO REFLECT A PORTION OF THE MICROWAVE ENERGY RADIATED FROM SAID OPENING BACK TOWARDS SAID MAGNETRON, THE REFLECTED WAVE VARYING AS A FUNCTION OF THE MOVEMENT OF THE STIRRER, SAID REACTIVE ELEMENT BEING LOCATED WITHIN SAID WAVEGUIDE AND DIMENSIONED RELATIVE TO SAID STIRRER SO THAT THE REFLECTED WAVES FROM SAID MATCHING ELEMENT AND STIRRER PRODUCE A RESULTANT WAVE IN THE DIRECTION TOWARDS THE MAGNETRON HAVING A GIVEN PHASE VARIATION THAT CORRESPONDS TO OPERATION OF THE MAGNETRON IN THE SINK REGION OF ITS CHARACTERISTIC DIAGRAM, SAID PHASE VARIATION PRODUCING A SUBSTANTIAL VARIATION IN THE MAGNETRON FREQUENCY THEREBY TO IMPROVE THE FIELD DISTRIBUTION WITHIN SAID HEATING CAVITY.