Abstract: A door assembly for a microwave oven that includes a deformable thin stainless steel plate which is sandwiched between a compression frame and a choke structure. To open the door, the plate is moved upward and away from the compression plate and the choke. In the closed position, the compression plate is pressed back under tension against the choke by the compression frame to prevent leakage of microwave energy. Tension force may be applied, for example, by the use of angled flanges or pneumatic door clamps. The door assembly is readily adaptable to both batch type and continuous feed processing. Because of the single moving lightweight plate, the assembly achieves a low cycle time access opening, eliminates the need for heavy and cumbersome structures which in turn also reduces the potential for injury.

Abstract: A feed that provides circularly polarized microwave energy such as for energizing a cavity in a microwave oven. The feed includes a transformer to match a linearly polarized rectangular waveguide to an exit waveguide which may be circular or square in cross section. The exit waveguide contains an asymmetrical element that provides symmetry about a plane only. The asymmetrical element therefore introduces a difference in microwave electrical phase of 90 degrees for polarizations which are respectively parallel to and perpendicular to the symmetry plane. The two components add to provide circularly polarized energy at constant magnitude but continually rotating phase. An extension may be used to modify the spread and matching of the energy from the exit waveguide into the enclosure.

Abstract: A door assembly for a microwave oven that includes a deformable thin stainless steel plate which is sandwiched between a compression frame and a choke structure. To open the door, the plate is moved upward and away from the compression plate and the choke. In the closed position, the compression plate is pressed back under tension against the choke by the compression frame to prevent leakage of microwave energy. Tension force may be applied, for example, by the use of angled flanges or pneumatic door clamps. The door assembly is readily adaptable to both batch type and continuous feed processing. Because of the single moving lightweight plate, the assembly achieves a low cycle time access opening, eliminates the need for heavy and cumbersome structures which in turn also reduces the potential for injury.