Patent ID: 6906297

Claim:
A method for microwave-heating prepared meals sealed in trays, in which the trays are placed in an autoclave into which microwaves are coupled from waveguides run only from a side of said autoclave ( 1 ) under a microwave-transparent conveying device ( 2 A) bearing said trays ( 3 ) and in which said trays are moved within and/or through said autoclave, the method comprising the steps of: irradiating said trays ( 3 ) with microwaves only from below; arranging decoupling openings in said waveguides immediately beneath the trays ( 3 ) to be heated, at a distance of less than one-half wavelength therefrom; alternating the positions of said decoupling openings between first and second positions along a direction generally transverse to the direction of movement of said conveying devise, associated with two different portions of said trays to be heated, at successive waveguides along said conveying device; and arranging said trays ( 3 ) so that each portion of each tray is irradiated only over alternate decoupling openings ( 10 ) of said waveguides ( 7 , 8 ).