MICROWAVE HEATING DEVICE

摘要

A waveguide structure antenna (5) has a top surface (9) and side wall surfaces (10a, 10b, 10c) defining a waveguide structure part (8), and a forward aperture (13), with microwaves being radiated from the forward aperture (13) toward an object being heated. The waveguide structure part (8) has a connecting part (7) that is connected to the top surface (9) of the waveguide structure part (8), and that allows the microwaves to be coupled to an internal space in the waveguide structure part (8). The waveguide structure part (8) radiates circularly polarized waves into a heating chamber from one or more microwave extraction openings (14) formed in the top surface (9). The microwave extraction openings (14) has a cross-slot shape wherein two slits (20a, 20b) intersect each other, and the openings are provided at a position offset from the tube axis (V). Among the distances from the center point (P1) in the intersection region of the cross-slot to the ends of the slits (20a, 20b), the distance to the end closest to the connecting part is the shortest. By means of this embodiment an object being heated that is placed in the central region of the placement surface can be heated uniformly.