Microwave heating apparatus

• US 8,901,470 B2
• Filed: 03/16/2009
• Issued: 12/02/2014
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Oomori, Yoshiharu, Nobue, Tomotaka, Yasui, Kenji, Mihara, Makoto
• Primary Examiner(s): VAN, QUANG T
• Application Number:
  US13/119,050
• Publication Number:
  US 20110168699A1
• Time in Patent Office: 2,087 Days
• Field of Search: 219/702, 219/751, 219/756, 219/746, 219/679, 219/680, 219/681, 219/678, 219/682, 219/686, 219/701, 219/730, 219/757, 219/759, 219/754, 219/762, 219/716, 219/761, 219/748, 426/107, 426/234, 426/241, 426/243, 426/395, 126/21.A, 126/21.R, 126/19.R, 126/299.D
• US Class Current: 219/748
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H05B 2206/044 Microwave heating devices provided with two or more magnetrons or microwave sources of other kind
• CPC Class Codes: H05B 6/686 Circuits comprising a signal generator and power amplifier, e.g. using solid state oscillators
• CPC Class Codes: H05B 6/705 using microwave tuning
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

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.

Claims

1. A microwave heating apparatus, comprising:

a heating chamber accommodating an article to be heated;

an oscillation part for generating microwaves;

a power division part for dividing an output of the oscillation part into a plurality of outputs and outputting the divided outputs;

amplification parts for respectively amplifying the outputs of the power division part;

feeding parts for respectively supplying outputs of the amplification parts to the heating chamber;

power detection parts for detecting reflected powers transmitted from the heating chamber to the amplification parts via the feeding parts; and

a control part for controlling an oscillating frequency of the oscillation part, wherein

each of the feeding parts integrally has a plurality of antennas for supplying the microwaves having different characteristics to the heating chamber, wherein the plurality of antennas emits the microwaves having the different characteristics to the heating chamber, and

the control part extracts the oscillating frequency at which a minimum reflected power is detected by the power detection parts, and causes the oscillation part 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.

2. The microwave heating apparatus according to claim 1, wherein

the output of one of the amplification parts is supplied to the plurality of antennas.

3. The microwave heating apparatus according to claim 2, wherein

the plurality of antennas emits the microwaves running in different excitation directions.

4. The microwave heating apparatus according to claim 2, wherein

the plurality of antennas has frequency characteristics with which frequency values indicating minimum reflected powers are different from each other.

5. The microwave heating apparatus according to claim 1, wherein

the outputs of the plurality of amplification parts are respectively and correspondingly supplied to the plurality of antennas in one of the feeding parts.

6. The microwave heating apparatus according to claim 5, wherein

the plurality of antennas emits the microwaves running in different excitation directions.

7. The microwave heating apparatus according to claim 5, wherein

each of the feeding parts having the plurality of antennas is a patch antenna having a plurality of feeding points.

8. The microwave heating apparatus according to claim 1, wherein

the output of one of the amplification parts is supplied to the plurality of antennas, and

at least one of the plurality of antennas is integrated with another antenna to which an output of the other amplification part is supplied.

9. The microwave heating apparatus according to claim 8, wherein

at least one of the plurality of antennas to which the output of one of the amplification parts is supplied and the other antenna to which the output of the other amplification part is supplied emit the microwaves running in different excitation directions.

10. The microwave heating apparatus according to claim 8, wherein

the plurality of antennas to which the output of one of the amplification parts is supplied has frequency characteristics with which frequency values indicating minimum reflected powers are different from each other.

11. The microwave heating apparatus according to claim 8, wherein

the plurality of antennas to which the output of one of the amplification parts is supplied emits the microwaves running in different excitation directions.

12. The microwave heating apparatus according to claim 1, further comprising:

a diffusive microwave power supply part in which the output of one of the amplification parts is supplied to the plurality of antennas provided in each of the feeding parts, and the plurality of microwaves having the different characteristics is supplied from the plurality of antennas to the heating chamber, wherein

the power detection parts are provided in microwave transmission passages between the amplification parts and the feeding parts so as to detect the reflected powers.

13. The microwave heating apparatus according to claim 1, further comprising:

an intensive microwave power supply part in which each of the feeding parts integrally has the plurality of antennas, the outputs of the plurality of amplification parts are respectively supplied to the plurality of antennas, and the plurality of microwaves having the different characteristics is supplied from the plurality of antennas to the heating chamber, wherein

the power detection parts are provided in microwave transmission passages between the amplification parts and the feeding parts so as to detect the reflected powers.

14. The microwave heating apparatus according to claim 1, provided with the feeding parts including a first feeding part and a second feeding part, the microwave heating apparatus further comprising:

a diffusive microwave power supply part in which the output of one of the amplification parts is supplied to the plurality of antennas provided in the first feeding part, and the plurality of microwaves having the different characteristics is supplied from the plurality of antennas of the first feeding part to the heating chamber; and

an intensive microwave power supply part in which the second feeding part integrally has the plurality of antennas, the outputs of the plurality of amplification parts are respectively supplied to the plurality of antennas of the second feeding part, and the plurality of microwaves having the different characteristics is supplied from the plurality of antennas of the second feeding part to the heating chamber, wherein

the power detection parts are provided in microwave transmission passages between the amplification parts and the feeding parts so as to detect the reflected powers.