High-efficiency heating device in microwave chamber and heating method thereof

1 . A high-efficiency heating device in a microwave chamber, comprising:

a heating chamber;

a straight-walled waveguide with an asymmetric transmission function; wherein one end of the straight-walled waveguide is communicated with the heating chamber; and

at least one group of microwave unidirectional propagation structures, which are attached to an inner sidewall of the straight-walled waveguide; wherein the at least one group of the microwave unidirectional propagation structures comprise a first medium section and a second medium section which are provided along a microwave transmission direction; wherein a dielectric constant of the first medium section gradually increases along the microwave transmission direction and has a maximum value of ε max , a dielectric constant of the second medium section is a constant value of ε c , and ε max =ε c ;

wherein a tail end of the second medium section protrudes out of the straight-walled waveguide and partially extends into an interior of the heating chamber.

2 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a head end of the second medium section is in directly connected with a tail end of the first medium section, or the second medium section and the first medium are a one-piece structure.

3 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a thickness of the second medium section is equal to a maximum thickness of the first medium section.

4 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a height of the at least of one group of the unidirectional waveguide structure is greater than or equal to ⅔ of a height of the inner sidewall of the straight-walled waveguide where the at least of one group of the unidirectional waveguide structures is attached.

5 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a groove group is provided on one outer surface of the first medium section, and the groove group comprises a plurality of longitudinal grooves provided in parallel from a head end to a tail end of the first medium section, and a depth of the plurality of longitudinal grooves gradually decreases from the head end to the tail end of the first medium section.

6 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a thickness of the first medium section gradually increases from a head end to a tail end of the first medium section.

7 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a medium hole group is provided inside the first medium section, and the medium hole group comprises a plurality of longitudinal medium holes provided in sequence along a direction from a head end to a tail end of the first medium section, interiors of the plurality of medium holes are provided with filling medium, a cross-sections of the plurality of medium holes are all circular, and diameters of the plurality of medium holes gradually increase or decreases in the direction from the head end to the tail and of the first medium section along the first medium section.

8 . The high-efficiency heating device in the microwave chamber, as recited in claim 1 , wherein a tray is further provided in the heating chamber for placing an object to be heated.

9 . A high-efficiency heating method in a microwave chamber, comprising: heating an object to be heated by using the high-efficiency heating device in the microwave chamber according to claim 1 , wherein the object to be heated is placed in the heating chamber in a static or movable manner.