Toroidal waveguide for a microwave cooking appliance

摘要

A microwave delivery system for a cooking appliance includes a toroidal waveguide having a ring diameter twice that of the wavelength of the microwaves produced by a magnetron, and a cross-sectional diameter equal to one-half of the produced microwaves. The waveguide includes a plurality of cavity excitation ports through which the microwaves enter a cooking cavity. The delivery system further includes a rotating stirrer positioned within the waveguide. The stirrer includes a plurality of openings which become aligned with the cavity excitation ports when the stirrer is rotated to create a uniform, high energy pattern of microwave energy to enter the cooking cavity. Finally, the waveguide includes a plurality of openings along spaced portions thereof to allow a flow of air through the waveguide.