Abstract: In a microwave heating apparatus of the invention, microwaves from oscillation parts 1a, 1b are divided into a plurality of microwaves by power division parts 2a, 2b and inputted to amplification parts 4a, 4b, 4c, 4d, and desired microwave powers from the amplification parts are supplied from feeding parts 5a, 5b, 5c, 5d to a heating chamber 8. Reflected powers reflected from the heating chamber to the amplification parts via the feeding parts are detected by power detection parts 6a, 6b, 6c, 6d. Each of the feeding parts has a plurality of antennas for supplying the microwaves having different characteristics to the heating chamber, and a control part 7 extracts an oscillating frequency with which the reflected powers detected by the power detection parts are minimum, and causes the oscillation parts to oscillate at the extracted oscillating frequency so as to supply the microwaves having the different characteristics from the plurality of antennas to the heating chamber.

Abstract: A microwave heating apparatus includes a microwave generation part 10 using a semiconductor element, and first and second heating chambers 100a, 100b to each of which a microwave generated in the microwave generation part is fed. A reflected microwave returned from at least one of the first and second heating chambers 100a, 100b to the microwave generation part is transmitted to the other heating chamber by a circulation type non-reciprocal circuit 118, so that generated power of the microwave generation part is substantially completely consumed upon heating of an article to be heated.

Abstract: To provide a microwave heating apparatus capable of heating various objects to be heated having different configurations, kinds, sizes, and amounts contained in a heating chamber with high efficiency by keeping low a reflected power of a microwave radiated from microwave supplying means, a microwave generator part includes oscillator parts (2a, 2b), power divider parts (3a, 3b), power amplifier parts (5a-5d), a heating chamber (10) containing the object to be heated, and a plurality of feeding parts (8a-8d, 9a-9d) arranged in a wall surface of the heating chamber to supply the microwaves therein, in which a phase difference and oscillation frequencies outputted from the feeding parts controlled as a pair are variably controlled.

Abstract: A microwave heating apparatus includes a microwave generation part (5) having a plurality of output parts, a heating chamber (4) to contain an object to be heated, a plurality of feeding parts (21a, 21b, 21c, 21d) supplying outputs of the plurality of output parts to the heating chamber, and a control part (6) controlling microwave radiation from the plurality of feeding parts to control an electromagnetic wave distribution in the heating chamber, in which a microwave is concentrated on the object to be heated put in the heating chamber.