Abstract: A self-cleaning combination microwave and electrically heated oven having a rotating microwave radiator positioned beneath a microwave transparent protective cover of high temperature material with air being blown by a microwave source into the oven through the radiating system and impinging on the cover, thereby cooling and assisting in preventing deposition of cooking vapors on the cover. During the self-cleaning cycle, air is drawn by convection through the oven to maintain the radiating system below 650.degree. F. while the interior oven surfaces are raised to temperatures above 900.degree. F. by resistive-heating elements in the oven.

Abstract: A microwave convection oven in which a gas burner positioned outside the oven cavity has its combustion products circulated through the oven through screens for preventing escape of the microwave energy from the oven cavity with the burner being of the multi-ported type providing high burner density and having secondary air closely adjacent all portions of the burner to reduce its incondescent flame length while permitting the burner to be positioned in a region between the screened vapor outlet region the oven and the inlet of a blower system for mixing the output of the burner with the vapor drawn from the oven thus the temperature of the vapor outlet region is maintained below that at which ionization of the vapor being drawn from the oven might produce leakage of microwave energy through the screen.

Abstract: A combination microwave and electrically heated oven having a door with a high temperature seal which inhibits the escape of hot gases around the periphery of the door and which is isolated from the major portion of the electric fields of the microwave energy entering the space between the door and the oven aperture walls by a slotted choke microwave seal so that the vapor seal may be formed which high microwave energy absorption characteristics without either reducing the intensity of microwave energy in the oven or causing substantial heating of the vapor seal by microwave energy.

Abstract: A combination electric heat and microwave oven employing a common cavity for cooking food with either microwave energy, electric resistance heating, or both in which the oven is supplied with microwave energy through a rotating multi-port radiator having a plenum fed from a magnetron through a waveguide and a coaxial line whose outer conductor extends into the plenum and whose central conductor supports said radiator.