摘要 |
The invention relates to a microwave heater comprising a plurality of microwave generators each emitting microwaves at a frequency in a range of frequencies ranging from 300 MHz to 5.8 GHz which couple into objects to be heated. At least one of the microwave generators emits the microwaves at a first frequency of an upper part of the range of frequencies, the microwaves of the first frequency displaying a first of depth of penetration into the objects to be heated; and at least one other of the microwave generators emits the microwaves at a second frequency of a lower part of the range of frequencies, the microwaves of the second frequency displaying a second depth of penetration into the objects to be heated, the first penetration depth being substantially smaller than the second penetration depth.
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