JP6826461B2 - High frequency heating device - Google Patents

Description

The present invention relates to a high frequency heating device that treats an object by microwaves.

In recent years, in industrial high-frequency heating devices used for household microwave ovens, agricultural and industrial products such as baked goods and wood drying, medical care and chemistry, etc., short-time heating of the object to be heated, partial heating of food, and heating state There is an increasing demand for real-time sensing, etc. In addition, in order to realize these demands, magnetrons, which have been the mainstream of microwave generators, will be shifted to solid-state microwave generators using high-frequency transmitters and high-frequency power amplifiers with high frequency stability. It is said. At present, when comparing the ratio of microwave power to price, the cost performance of magnetrons is extremely high, and the cost is high for circuits using solid-state microwave generators of high-frequency transmitters and high-frequency power amplifiers composed of semiconductors. .. However, it is thought that cost reduction will progress as more units are commercialized in the future. If the shift to the solid-state microwave generator progresses in this way, frequency stability will be improved and frequency control and phase control will be possible, but a detection circuit that detects this with high accuracy will be extremely important. By improving this detection technology, it is possible to obtain further functional improvements such as shortening the load heating time and partial heating by grasping the load state and performing detailed control.

JP 2011-138721 JP 2013-33601

The microwave generated by the microwave generator is sent to the radiating means (antenna, etc.) that radiates the microwave to the object to be heated placed in the heating chamber using the transmission line (traveling wave). At this time, when the inside of the heating chamber is in a no-load state (no object to be heated), the electric power is reflected in the heating chamber without loss and most of the microwave power is returned to the microwave generator (reflected wave). In the worst case, the reflected wave in this no-load state or a state close to no-load causes great damage to the microwave generator and shortens the life. Therefore, in order to absorb the reflected wave and protect the microwave generator, a circulator circuit and an isolator circuit must be added separately, and an increase in cost and an increase in traveling wave loss have been problems.

It can also be used for load state detection, which captures state changes such as changes in water content when the object to be heated in the refrigerator is heated by the ratio of the electric power of the traveling wave and the reflected wave. However, it is necessary to detect the ratio of the traveling wave power and the reflected wave power with high accuracy, and it has not been possible to grasp the ratio with high accuracy by the conventional detection circuits. For example, in the case of a microwave oven for home use, the cause of this is that the detection circuit unit must be as small as possible due to the demand for miniaturization of the entire microwave oven, and a sufficient area cannot be obtained. Further, if the detection circuit area is restricted, there is a problem that the accuracy is lowered at the expense of the directional coupler performance for detecting the traveling wave power and the reflected wave power.

In order to solve the above-mentioned problems, the present invention uses a microwave generation unit having a source for generating one or more microwaves, a heating chamber, and microwave emitting means installed inside the heating chamber. A high-frequency heating device that uses microwaves radiated into the heating chamber to heat an object, and is a traveling wave or reflected wave on a transmission line for transmission from the microwave generation unit to the microwave emitting means. a coupling circuit for coupling the power, the coupling circuit coupled with a traveling wave, the power value of the reflected wave has a converter for converting the comparable signal, frequency as the microwave radiation prior Symbol microwave generating unit It is a high-frequency heating device that detects a load state based on the characteristics of at least one of a traveling wave and a reflected wave, which is detected when the antenna angle and the rotation angle of the means are changed in combination .

According to the present invention, it is not necessary to separately add a circulator circuit or an isolator circuit for absorbing the reflected wave that causes great damage to the microwave generator and shortening the life of the microwave generator and protecting the microwave generator, and the cost is high. It is possible to suppress the rise of the wave and the increase of the loss of the traveling wave. In addition, although it is small, it is possible to detect the load state with high accuracy by detecting the ratio of the traveling wave power and the reflected wave power with high accuracy.

It is a figure which shows the structure of the high frequency heating apparatus which is 1st Example of this invention. It is a figure which shows the structure of the high frequency heating apparatus which is 2nd Example of this invention. It is a figure which shows the structure of the high frequency heating apparatus which is 3rd Example of this invention. It is a figure which shows the structure of the high frequency heating apparatus which is 4th Example of this invention. It is a figure which shows the microwave generation pattern generated in the microwave generation unit of the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the relationship between the frequency or the antenna angle of the high frequency heating apparatus which is 1st to 4th Examples of this invention, and reflected power. It is a figure which shows the relationship between the frequency of the traveling wave power and the reflected wave power of the high frequency heating apparatus which is 1st to 4th Examples of this invention, or the antenna angle and electric power. It is a figure which shows the operation and direction | direction of the directional coupler of the high frequency heating apparatus which is 1st to 4th Examples and 9th to 11th Embodiment of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention. It is a figure which shows the structure of the coupling circuit used in the high frequency heating apparatus which is 1st to 4th Examples of this invention.

In the present invention, a detection circuit such as a directional coupler for detecting the state of no load or load is added, and the traveling wave power output from the microwave generator and the reflected wave power for the load in the heating chamber are monitored. By doing so, it is possible to keep the electric power output from the microwave generator in a state in which the source of the microwave is not destroyed or the reliability is not deteriorated. In addition, if the reflected wave does not destroy the microwave source or reduce the reliability, the frequency, phase, and frequency of the microwave generator are adjusted so that the reflected wave is minimized with respect to the load in the heating chamber. By combining changes in the rotation angle of the radiating means (antenna, etc.) that emits microwaves, or if there are multiple radiating means, the frequency, phase, and radiating means (antenna) of each microwave generator. By optimally combining the changes in the rotation angle of the above), it is possible to protect the microwave generator, reduce the cost increase, and reduce the increase in the loss of the traveling wave.

In addition, the ratio of the power amount of the traveling wave and the reflected wave or the reflected wave power is the ratio of the power amount of the traveling wave and the reflected wave, or the directional coupler, etc. By adding a detection circuit and constantly monitoring the traveling wave power output from the microwave generator and the reflected wave power for the load in the heating chamber, the change in water content and the dielectric constant of the object to be heated (relative permittivity, It becomes possible to grasp the state such as dielectric loss).

Directionality is important as one of the indexes that determine the performance of the directional coupler in order to improve the detection accuracy of the directional coupler used for detecting the no-load or load state. The directional coupler will be described with reference to FIG.

The traveling wave output from the microwave generator passes through the directional coupler, reaches the radiating means (antenna, etc.) that radiates the microwave, and is radiated into the heating chamber. Here, if the inside of the heating chamber is unloaded (no object to be heated) or the loss under load is small, a reflected wave is generated and returns to the microwave generator, but if this reflected wave is large, it is inside the microwave generator. Destruction or loss of reliability occurs in existing microwave sources. Further, by detecting the ratio of the reflected wave power to the traveling wave power or the reflected wave power, the state inside the heating chamber can be grasped.

As the operation of the directional coupler, the traveling wave T value input from the port1 terminal is coupled at a constant ratio to obtain the coupled traveling wave TC. Similarly, the coupled reflected wave RC is obtained by coupling the reflected wave R value input from the port2 terminal at a constant ratio. From the ratio of the coupled traveling wave TC and the coupled reflected wave RC, it is possible to obtain the reflected wave under load. The operation and directionality of the directional coupler are shown in FIG.

In addition, the directionalness, which is an index for improving the detection accuracy of this directional coupler, is output to port4, which is a terminal for detecting the coupled reflected wave RC by coupling the reflected wave R value at a constant ratio. It indicates how much the coupled reflected wave RC leaks from the traveling wave T, and is defined by directional D = coupled reflected wave RC-leaking traveling wave TL. If this direction D is a large value at a desired frequency, the leakage traveling wave TL will be extremely small and will not affect the coupled reflected wave RC, and measurement will be possible with high accuracy. However, when trying to realize the directionality in a wide band and at a high value, it is necessary to arrange a circuit such as arranging a plurality of coupling parts at 1/4 wavelength in order to cancel the leakage traveling wave TL, so that the area is large. Although it will increase, when only the reflected wave power is detected as in the relationship between the frequency or antenna angle shown in FIG. 6 and the reflected power, the difference between the maximum value and the minimum value of the reflected wave power at no load ΔP_open It is possible to detect the load state by comparing the difference between the maximum value and the minimum value of the reflected wave power under load and the difference of ΔP_load.

Further, as a method for further improving the accuracy, FIG. 7 shows the relationship between the frequency of the traveling wave power and the reflected wave power, or the relationship between the antenna angle and the power. Here, the difference between the maximum and minimum values of the traveling wave power under load ΔP_Twave and the difference between the maximum and minimum values of the reflected wave power ΔP_Rwave are obtained, and the maximum value of the traveling wave power under no load is obtained. Find the difference between the minimum value ΔP_Twave and the difference between the maximum and minimum values of the reflected wave power ΔP_Rwave ΔP_Open. By finding the difference between the obtained ΔP_Load and ΔP_Open, it is possible to detect the load state with higher accuracy. With these methods, it is possible to realize a high-frequency heating device characterized by high-precision load detection.

Change at least one of the maximum and minimum values of the characteristics obtained from the difference or ratio between the power value signal of the traveling wave and the power value signal of the reflected wave, and the frequency or the angle or rotation angle of the microwave emitting means. The load state may be detected by comparing the relationships when they are made to do so. Or
When at least one of the maximum and minimum values of the power value signal of the traveling wave and the power value signal characteristic of the reflected wave and at least one of the frequency and the angle or rotation angle of the microwave emitting means are changed. The load state may be detected by comparing the relationships of.

Hereinafter, with reference to the drawings, a basic configuration of a high-frequency heating device, which is a mode for carrying out the present invention (hereinafter referred to as an embodiment), will be described with reference to FIG. 1, and then a feature configuration of the present embodiment will be described. Will be described with reference to each figure. Further, in each figure, common components and similar components are designated by the same reference numerals, and duplicate description thereof will be omitted.

FIG. 1 is a diagram showing a configuration of a high-frequency heating device according to a first embodiment of the present invention. The high-frequency heating device 101 is a heating chamber 102, a microwave emitting means 103, a coupling circuit 104 that combines electric power of traveling waves and reflected waves, a microwave generating unit 105, and an inverter circuit that supplies electric power to the microwave generating unit 105. Operation control, power consumption calculation in the inverter, detection / calculation to convert each power value of the traveling wave power and the reflected wave power obtained by the coupling circuit 104 that combines the power of the traveling wave and the reflected wave into a measurable electric signal. -Has a control circuit unit, and the microwave power output from the microwave generation unit 105 is transmitted to the heating chamber 102 by a low-loss transmission line. In the heating chamber 102, the object to be heated is irradiated from the microwave emitting means 103 by a rotating antenna or the like. The microwave radiating means 103 by a rotating antenna or the like operates so as to prevent uneven heating of the object to be heated by rotating and to make the heating temperature of the object to be heated uniform. However, since it is difficult to make the heating temperature of the object to be heated uniform only by the microwave emitting means 103 using a rotating antenna or the like, the heating temperature of the object to be heated is further changed by changing the frequency of the microwave generation unit 105. Can be made uniform. When the frequency of the microwave generation unit 105 is changed, the power of the traveling wave and the reflected wave is monitored by the coupling circuit 104 that combines the power of the traveling wave and the reflected wave, and the reflected wave power / traveling wave power is small. Control is performed so as to change the angle, rotation angle, or frequency of the microwave generation unit 105 of the microwave emitting means 103 by a rotating antenna or the like.

In addition, Fig. 5 shows the microwave generation pattern when the object to be heated is heated. As a method for controlling the microwave power, the method of heating by the burst wave in which the heating time Ton and the OFF time Toff are changed shown in the microwave generation pattern A and the method shown in the microwave generation pattern B are shown. Heating time Ton and OFF time A method is used in which the signal power of the Ton burst wave with a fixed heating time Ton burst wave is gradually increased. At the start of heating, the microwave generation pattern B is used, and in the steady state, the microwave generation pattern A is used to control the heating time and the heating homogenization of the object to be heated by changing the heating time Ton and OFF time Toff time. If the microwave generation pattern A and the microwave generation pattern B are controlled together, a finer heating time and uniform heating control of the object to be heated can be realized. Further, there is no problem in controlling only one of the microwave generation pattern A and the microwave generation pattern B.

Furthermore, in order to obtain the load state in the heating chamber 102 at the start of heating, the traveling wave power per unit time is reduced by shortening the heating time Ton and lengthening the OFF time Toff time in the microwave generation pattern A. This makes it possible to suppress the reflected wave power even in a no-load state in which there is no object to be heated in the heating chamber 102, so that damage to the microwave generation unit 105 can be reduced. Further, in the microwave generation pattern A, by reducing the electric power at the heating time Ton, the traveling wave electric power at the start can be reduced, and it is assumed that there is no object to be heated in the heating chamber 102 and there is no load. Even so, the reflected wave power can be suppressed. If the microwave generation pattern A and the microwave generation pattern B are controlled together, more detailed traveling wave power control can be realized.

FIG. 2 is a diagram showing a configuration of a high-frequency heating device according to a second embodiment of the present invention. The high-frequency heating device 201 is a power distributor that distributes electric power to a heating chamber 202, a microwave emitting means 203, a coupling circuit 204 that combines the electric power of a traveling wave and a reflected wave, a microwave generating unit 205, and a microwave emitting means 203. 206, operation control of the inverter circuit that supplies power to the microwave generation unit 205, power consumption calculation in the antenna, traveling wave power and reflected wave power obtained by the coupling circuit 204 that combines the power of the traveling wave and the reflected wave. It has a detection / calculation / control circuit unit that converts each power value of the above into a calculable electric signal, and the microwave power output from the microwave generation unit 205 is transmitted to the power distributor 206 by a low-loss transmission line. It is distributed to the microwave emitting means 203 by a plurality of antennas provided in the heating chamber 202, and the object to be heated is irradiated. The power supply to the microwave radiating means 203 by the plurality of antennas provided in the heating chamber 202 may be distributed to the number of antennas used in the power distributor 206. By using the microwave radiating means 203 with a plurality of antennas provided in the heating chamber 202, it operates so as to prevent uneven heating of the object to be heated and to make the heating temperature of the object to be heated uniform. However, since it is difficult to make the heating temperature of the object to be heated uniform only by the microwave radiating means 203 using a plurality of antennas provided in the heating chamber 202, the frequency of the microwave generation unit 205 is further changed. As a result, the heating temperature can be made uniform. When the frequency of the microwave generation unit 205 is changed, the power of the traveling wave and the reflected wave is monitored by the coupling circuit 204 that combines the power of the traveling wave and the reflected wave, and the reflected wave power / traveling wave power is small. Control is performed so as to change the frequency in the microwave generation unit 205 so as to be.

Further, the description of the microwave generation pattern when the object to be heated is heated is the same as that in the first embodiment.

FIG. 3 is a diagram showing a configuration of a high-frequency heating device according to a third embodiment of the present invention. The high-frequency heating device 301 includes a heating chamber 302, a microwave emitting means 303, a coupling circuit 304 that combines electric power of traveling waves and reflected waves, a microwave generating unit 305, and an inverter circuit that supplies electric power to the microwave generating unit 305. Operation control, power consumption calculation in the inverter, detection / calculation to convert each power value of the traveling wave power and the reflected wave power obtained by the coupling circuit 304 that combines the power of the traveling wave and the reflected wave into a measurable electric signal. -Has a control circuit unit, and the microwave power output from the microwave generation unit 305 is transmitted to the heating chamber 302 by a low-loss transmission line. In the heating chamber 302, the object to be heated is irradiated from the microwave emitting means 303 by a rotating antenna or the like. The microwave radiating means 303 by a rotating antenna or the like operates so as to prevent uneven heating of the object to be heated by rotating and to make the heating temperature of the object to be heated uniform. However, since it is difficult to make the heating temperature of the object to be heated uniform only by the microwave emitting means 303 using a rotating antenna or the like, the microwave generating unit 305 outputs at least one frequency from f1 to fn. As a result, the heating temperature of the object to be heated can be made uniform. When the microwave generation unit 305 outputs at least one frequency from f1 to fn, the power of the traveling wave and the reflected wave is monitored by the coupling circuit 304 that combines the power of the traveling wave and the reflected wave, and the reflected wave. The rotation angle of the microwave emitting means 303 by a rotating antenna or the like is controlled so that the power / traveling wave power is reduced, or the microwave generation unit 305 is controlled to output at least one frequency from f1 to fn.

Further, the description of the microwave generation pattern during heating of the object to be heated is the same as in the first embodiment, but when a plurality of microwave generation units 305 are operated in f1 to fn, they are always generated. It is not necessary to have the same microwave generation pattern. This may be because all microwave generation patterns are different, for example, any one of f1 to fn in the microwave generation unit 305 may be operating instantaneously.

FIG. 4 is a diagram showing a configuration of a high-frequency heating device according to a fourth embodiment of the present invention. The high-frequency heating device 401 goes to the heating chamber 402, the microwave emitting means 403a to 403d, the coupling circuits 404a to 404d that combine the power of the traveling wave and the reflected wave, the microwave generating units 405a to 405d, and the microwave generating units 405a to 405d. Operation control of the inverter circuit that supplies the power of, calculation of power consumption in the antenna, calculation of each power value of the traveling wave power and the reflected wave power obtained by the coupling circuits 404a to 404d that combine the power of the traveling wave and the reflected wave. It has a detection / calculation / control circuit unit that converts it into a possible electric signal, and the microwave power output from the microwave generation units 405a to 405d is transmitted by a low-loss transmission line using multiple antennas provided in the heating chamber 402. It is transmitted to the microwave emitting means 403a to 403d and irradiates the object to be heated. By using the microwave radiating means 403a to 403d by a plurality of antennas provided in the heating chamber 402, it operates so as to prevent uneven heating in the object to be heated and to make the heating temperature of the object to be heated uniform. However, it is difficult to make the heating temperature of the object to be heated uniform only by the microwave radiating means 403a to 403d using a plurality of antennas provided in the heating chamber 402. In the microwave generation units 405a to 405d, all frequencies of f1 to fn may be different or the same frequency, and by outputting microwaves of these frequencies, the heating temperature of the object to be heated can be made uniform. Can be planned. When output is performed by the microwave generation units 405a to 405d, the power of the traveling wave and the reflected wave is monitored by the respective coupling circuits 404a to 404d that combine the power of the traveling wave and the reflected wave, and the respective reflected wave power / In the microwave generation units 405a to 405d so that the traveling wave power is reduced, all frequencies of f1 to fn may be different or may be the same frequency, and control is performed so as to output microwaves of these frequencies. Do.

Further, the description of the microwave generation pattern during heating of the object to be heated is the same as that in the first embodiment, but when a plurality of microwave generation units 405a to 405d are operated in f1 to fn, they are described. Do not always have the same microwave generation pattern. This may be because all microwave generation patterns are different, for example, any one of f1 to fn in the microwave generation units 405a to 405d may be operating instantaneously.

FIG. 9 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high-frequency heating device according to the fifth embodiment of the present invention. The coupling circuit is composed of a main line 601, a coupling line 602, a dielectric 603, and a ground 604 microstrip line, and the microwave output from the microwave generation unit is used as a microwave emitting means on the main line 601. Be supplied. At this time, the powers of the traveling wave and the reflected wave are combined on the coupling line 602.

FIG. 10 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high-frequency heating device according to the sixth embodiment of the present invention. The coupling circuit is composed of a strip line of a main line 701, a coupling line 702, a dielectric 703, and a ground 704, and the microwave output from the microwave generation unit is supplied to the microwave emitting means by the main line 701. Will be done. At this time, the powers of the traveling wave and the reflected wave are combined on the coupling line 702.

FIG. 11 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high-frequency heating device according to the seventh embodiment of the present invention. The coupling circuit is composed of a waveguide main line 801 and a microstrip coupling line 802a and 802b, a microwave input / output terminal 803, and a coupling hole 804, and the microwave input from the microwave input / output terminal 803 is coupled. It is coupled in hole 804 and transmitted to the microstrip coupling lines 802a, 802b. Here, the microstrip coupling lines 802a and 802b are not in contact with the upper surface of the waveguide main line 801 but are actually in contact with the upper surface of the waveguide main line 801 of the coupling hole 804 center line. Further, in order to increase the directionality of the directional coupler, the microstrip coupling lines 802a and 802b are rotated to obtain the optimum point.

FIG. 12 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high-frequency heating device according to the eighth embodiment of the present invention. The coupling circuit is composed of a waveguide main line 901, a microstrip coupling line 902, a microwave input / output terminal 903, and a coupling hole 904, and the microwave input from the microwave input / output terminal 903 is a coupling hole 904. It is coupled with and transmitted to the microwave coupling line 902. Here, the microstrip coupling line 902 is not in contact with the upper surface of the waveguide main line 901, but is actually in contact with the upper surface of the waveguide main line 801 of the center line of each coupling hole 904. Here, in order to enhance the directionality of the directional coupler, a plurality of coupling holes 904 are arranged in a length proportional to the frequency.

FIG. 13 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high-frequency heating device according to the ninth embodiment of the present invention. The coupling circuit is composed of a waveguide main line 1001 and a strip coupling line 1002, and a strip line is used as the coupling line, and the operation is equivalent to that of the eighth embodiment.

FIG. 14 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high-frequency heating device according to the tenth embodiment of the present invention. The coupling circuit is composed of a waveguide main line 1101 and a coaxial coupling line 1102, and a coaxial line is used as the coupling line, and the operation is equivalent to that of the eighth embodiment.

FIG. 15 is a diagram showing a configuration of a coupling circuit for coupling the power of a traveling wave and a reflected wave used in the high frequency heating device according to the eleventh embodiment of the present invention. The coupling circuit is composed of a waveguide main line 1201 and a coaxial coupling line 1202, and a coaxial line is used as the coupling line, and the operation is equivalent to that of the eighth embodiment.

High frequency heating device 101, 201, 301, 401
Heating chambers 102, 202, 302, 402
Microwave emitting means 103, 203, 303, 403a to 403d
Coupling circuits 104, 204, 304, 404a-404d
Microwave generation unit 105, 205, 305, 405a ~ 405d
Main track 601, 701,
Combined lines 602, 702
Dielectric 603, 703
Grand 604, 704
Waveguide main line 801, 901, 1001, 1101, 1201
Microstrip coupling line 802a, 802b, 902
Strip coupling line 1002
Coaxial coupling line 1102, 1202
Microwave input / output terminals 803, 903
Bonding holes 804, 904

Claims (11)

It has a microwave generation unit having a source for generating one or more microwaves, a heating chamber, and microwave emitting means installed inside the heating chamber, and uses microwaves radiated into the heating chamber. A coupling circuit that couples the power of traveling waves and reflected waves to a transmission line for transmitting from the microwave generation unit to the microwave emitting means, which is a high-frequency heating device that heats an object, and the coupling circuit. It has a converter that converts the power values of the combined traveling wave and reflected wave into comparable signals.
Based on the characteristics of the power value signal of at least one of the traveling wave and the reflected wave detected when the frequency of the microwave generating unit and the antenna angle and the rotation angle of the microwave emitting means are changed in combination. , A high frequency heating device characterized by detecting a load state. The first aspect of the present invention is that the characteristic of at least one of the traveling wave and the reflected wave is a comparison of the difference value or the ratio between the maximum value and the minimum value of the characteristic of the power value signal. High frequency heating device. The high-frequency heating device according to claim 1, wherein the characteristic of the power value signal of the reflected wave is a comparison of a difference value or a ratio of a maximum value and a minimum value of the characteristic of the power value signal of the reflected wave. In claim 1, the characteristic of the power value signal of at least one of the traveling wave and the reflected wave is the maximum value of the characteristic obtained from the difference value or the ratio of the power value signal of the traveling wave and the power value signal of the reflected wave. A high frequency heating device characterized in that it is a comparison of the difference value or the ratio between the minimum value and the minimum value. In claim 1, the characteristic of the power value signal of at least one of the traveling wave and the reflected wave is the maximum value of the characteristic obtained from the difference value or the ratio of the power value signal of the traveling wave and the power value signal of the reflected wave. A high-frequency heating device, which is a comparison of the relationship between the minimum value and the minimum value, the frequency of the microwave generation unit, and the antenna angle and rotation angle of the microwave emitting means in combination and changed. In claim 1, the characteristic of at least one of the traveling wave and the reflected wave is the maximum value and the minimum value of at least one of the power value signal of the traveling wave and the power value signal characteristic of the reflected wave. A high-frequency heating device, which is a comparison of the relationship between the frequency of the microwave generation unit and the antenna angle and rotation angle of the microwave emitting means in combination and changed. In the source that generates one or more microwaves according to any one of claims 1 to 6, the signal irradiating the object to be heated is set as a burst wave, and the ON time and OFF time are controlled to control the traveling wave. Any of claims 1 to 4 in which the burst wave ON time of the microwave is shortened until the source of the microwave is not destroyed or the reliability is not deteriorated when measuring the power value signal and the power value signal power of the reflected wave. The high-frequency heating device described in one. In the source that generates one or more microwaves according to any one of claims 1 to 6, the signal irradiating the heated object is used as a burst wave to control the ON time, the OFF time, and the power at the time of ON. However, when measuring the traveling wave power value signal and the reflected wave power value signal power, the burst wave ON time of the microwave is shortened until the source of the microwave is not destroyed or the reliability is not deteriorated. apparatus. Any of claims 1 to 8 wherein the transmission line for transmission to the microwave emitting means is a waveguide and the coupling circuit for coupling the electric power of the reflected wave and the traveling wave is composed of a microstrip line or a strip line. The high frequency heating device described in one. The invention according to any one of claims 1 to 8, wherein the transmission line for transmission to the microwave emitting means and the coupling circuit for coupling the electric power of the reflected wave and the traveling wave are composed of a microstrip line or a strip line. High frequency heating device. The power value signal of the traveling wave detected when the frequency of the microwave generating unit and the rotation angle of the microwave emitting means are changed in combination is the power value signal of the microwave generating unit having a source for generating microwaves. The high-frequency heating device according to claim 9, which is obtained from power consumption.

Images