Patent ID: 8907259

Claim:
A microwave irradiation device comprising: a chamber configured to accommodate an object to be processed; a plurality of magnetrons configured to generate and irradiate microwaves to the object to be processed in the chamber; and a power supply unit configured to supply voltage pulses to the magnetrons, wherein the power supply unit supplies the voltage pulses to the magnetrons while preventing the voltage pulses supplied to the magnetrons from temporally overlapping with each other, wherein the plurality of magnetrons include at least a first magnetron, a second magnetron, a third magnetron, and a fourth magnetron, wherein the power supply unit at least includes, an AC/DC conversion unit configured to convert an AC power to a DC power, a first and a second switching circuit to which the converted DC power is inputted, each switching circuit having a plurality of switching transistors, and the first and the second switching circuit respectively outputting a first and a second pulse-shaped voltage by combining outputs from the switching transistors, a switching control unit configured to control the first and the second switching circuit, a first voltage supply circuit configured to alternately supply voltage pulses to the first and the second magnetron based on the first pulse-shaped voltage outputted from the first switching circuit, and a second voltage supply circuit configured to alternately supply voltage pulses to the third and the fourth magnetron based on the second pulse-shaped voltage outputted from the second switching circuit, and wherein a first voltage pulse from the first voltage supply circuit is firstly supplied to the first magnetron by a part of the switching transistors of the first switching circuit; and then a second voltage pulse from the second voltage supply circuit is supplied to the third magnetron by a part of the switching transistors of the second switching circuit; and then a third voltage pulse from the first voltage supply circuit is supplied to the second magnetron by the remaining part of the switching transistors of the first switching circuit; and then a fourth voltage pulse from the second voltage supply circuit is supplied to the fourth magnetron by the remaining part of the switching transistors of the second switching circuit.