| 摘要 |
An excitation system for a microwave cooking appliance which employs a low profile rotating disk to enhance time-averaged uniformity of energy distribution within the resonant cooking cavity. A rectangular waveguide couples energy from the magnetron to the cooking cavity. A circular opening is formed in a common wall between the waveguide and the cooking cavity, which opening is essentially blocked by a rotatable metallic disk overlapping the opening on the cavity side of the wall. An elongated radiating slot is formed on the disk for coupling energy from the waveguide to the cooking cavity extending generally transverse to the radius of the disk. The axis of rotation of the disk is longitudinally spaced an odd integral multiple of quarter guide wavelengths from the short circuit termination of the waveguide, and the longitudinal axis of the radiating slot is radially spaced approximately one quarter guide wavelength from the axis of rotation of the disk, thereby orienting the slot alternately as a series slot at a maximum wall current point and a shunt slot at a maximum field point with each quarter revolution of the disk. During each complete rotation of the disk, the slot passes through four maximum energy coupling positions with less optimum coupling positions interspersed therebetween, thereby enhancing time-averaged energy distribution uniformity in the cavity by periodically varying the radiation intensity of the slot and its position in the cavity during each rotation of the disk.
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