Beam stirrer
AssigneeMicro-Tronics, Inc.
InventorTheodore S. Saad
Life of this patent
Estimating the term…
Abstract
A microwave oven having means defining an oven cavity, a magnetron microwave power source, a waveguide for coupling energy from the magnetron to the oven cavity and preferably a mode matching transformer for establishing primarily only the dominant mode in the oven cavity. A beam stirrer is disposed adjacent the waveguide feed into the cavity and is in the form of a resonant structure for coupling the energy to the cavity. The resonant structure is rotated in an eccentric manner to spread the energy beam to thereby provide a more uniform heating pattern. In one specific form the resonant structure is a cylinder of relatively short length and dimensioned to provide good matching with the magnetron source along with beam motion.
Claims14
In a microwave oven having means defining an oven cooking area, a source of microwave energy, and a waveguide means coupling the energy from the source to the cooking area, the improvement comprising;
- an energy coupling structure disposed in the oven cooking area in a position adjacent one end of the waveguide means to receive the coupled energy and including a substantially continuous ring member defining a coupling opening extending in the direction from the waveguide means to the oven cooking area, means eccentrically supporting the structure from a wall adjacent the one end of the waveguide means and means for rotating the supporting means to in turn rotate the structure to thereby move the energy beam in many directions with the opening in the coupling structure being maintained extending in substantially the same direction as the structure is rotated so that the energy is coupled relatively uniformly as the structure rotates.
In a microwave oven having means defining an oven cavity, a source of microwave energy, and means coupling the energy from the source to the cavity, the improvement comprising;
- a beam stirrer disposed in the oven cavity in a position to receive the coupled energy and including a cylindrical body of approximately quarter wave length height, means eccentrically supporting the structure including a shaft and tab means for securing the shaft close to one section of the body and motor means coupled to the shaft for rotating the cylindrical body to thereby deflect the beam in many directions with the energy being coupled relatively uniformly as the structure rotates, wherein a small angle is provided between the center line of the shaft and the center line of the body.
In a microwave oven having a source of microwave energy, a cooking cavity and waveguide means coupling from the source to an opening into the cooking cavity, a beam stirrer disposed adjacent the opening and comprising a resonant structure that represents a relatively low impedance to the energy, is disposed adjacent the opening into the cooking cavity and covers a first area intermediate the opening and cooking cavity and means for eccentrically rotating the structure to spread the energy beam without substantially disrupting the impedance to energy and so that the structure when rotating covers a second area larger than said first area and also intermediate the opening and cooking cavity.
A microwave oven comprising;
- a source of microwave energy,
- a waveguide of predetermined cross-section positioned with one end receiving energy from said source for transmission through said waveguide,
- the frequency of operation of said source and the dimension of said waveguide being selected to excite the dominant mode in said waveguide,
- means defining an enclosure including means for providing access to the enclosure and means defining an opening into the enclosure,
- matching means coupling from the other end of the waveguide to the opening in the enclosure for establishing primarily only the dominant mode in the enclosure,
- and energy coupling and directing means disposed at the opening to the enclosure and including a ring structure dimensioned to act as a low impedance to the energy and covering a first area and means for rotating the ring structure to cover a second area larger than the first area.
Dependencies are inferred from the claim text.