Abstract: An arrangement for illuminating the interior of a microwave oven cavity comprises a lamp (21) mounted in a lamp holder (19, 20) which is disposed outside the oven cavity behind a window in a cavity wall (10). The lamp holder (19, 20) is arranged axially within an electrically conductive sleeve (12) mounted on the outside of the cavity wall (10) and connected to cavity wall parts surrounding an aperture (11) in the cavity wall bounding the window so that the lamp (21) is axially arranged within the sleeve (12). The sleeve (12) constitutes a waveguide having the aperture (11) as input and having a cut-off wavelength smaller than the operating wavelength of the microwave oven, and the mounted lamp (21) has its filament (22) at a sufficient distance (H) from the aperture (11) for leaking microwave energy reaching the filament (22) to have been considerably attenuated. Microwave energy leakage is thereby substantially prevented both if the lamp (21) is mounted and if the lamp (21) is absent.

Abstract: An energy feed system for microwave ovens includes a rotatable slotted disc (24) arranged within the oven cavity (10) in front of a feeding aperture (22) in a cavity wall (11). The disc is essentially larger than the feeding aperture and is arranged at a small distance from the cavity wall (11) so that a narrow space (42') is formed between this wall (11) and the disc, through which microwave energy can propagate radially outwardly. The disc comprises a number of slots (27-29, 46-51), oriented transversely to their respective radial position vectors and dimensioned so as to serve as antenna elements for radiating energy into the interior of the oven cavity (10). The disc is journalled eccentrically so as to perform simultaneously a rotational and a translational motion and the narrow space between the disc and the cavity wall is also utilized for guiding an air stream to impinge on vanes (30-32, 44, 45) secured to the lower side of the disc so as to cause the disc to rotate in a predetermined direction.