Abstract: A supply wave guide system for microwave ovens consists of a wave guide of constant height and continuously varying width, which wave guide is terminated at the wider end by a short-circuiting wall. Microwave energy is fed into the wave guide at its smaller end. Microwave energy is fed from the waveguide into the oven cavity through at least two coupling apertures situated at the wider part of the wave guide and leading directly into the cavity, in which apertures stirrers, preferably movable and in the shape of rotating metallic wings, are situated.

Abstract: A sealing arrangement for microwave ovens comprising a quarter wave choke situated in the door and having an entrance opening into the choke in the rim portions of the door, which consists of a door frame, and a suitably perforated metallic door sheet covering the space inside the frame. According to the invention the door frame comprises an integral piece of conductive material having, in section, a generally U-shaped configuration, forming said quarter wave choke, with the outer leg of the U shorter than the inner leg, the door sheet is situated in a plane with the outer end of the inner leg of the U, where it is electrically connected to the said leg. The metallic door sheet extends beyond the inner leg and beyond the shorter, outer leg of the U so that the entrance opening to the inside of the U, forming the cavity of the quarter wave choke, is constituted by the gap between the outer shorter leg of the U and the extension of the metallic door sheet.

Abstract: In a microwave oven use is made of a combination of a sealing in the form of a quarter-wave choke, arranged in the edge of the door, and a safety switch which is operated by the door. The entrance opening to the quarter-wave choke is situated at such a distance from the outer edge of the door that the sealing is still fully effective at the instant at which the safety switch is actuated by the opening of the door.