High-frequency heating device

Abstract

To provide a radio frequency heating apparatus that maximizes heating by surface waves in a configuration in which radio frequency power propagates through a surface wave line in the form of surface waves and heats an object to be heated installed near the surface wave line.SOLUTION: A radio frequency heating apparatus includes a surface wave line 7 for propagating surface waves, a power feeding unit 6 that supplies high frequency power to the surface wave line 7, and a coupling unit that couples the surface wave line 7 and the power feeding unit 6, and at least one matching unit 9a is provided between the coupling unit 6 and a terminal end unit 8 of the surface wave line 7.SELECTED DRAWING: Figure 7

Description

Technical Field

[0006] , , , , , ,

[0001] The present disclosure relates to a high-frequency heating device in which a surface wave propagates.

Background Art

[0002] Patent Document 1 states that by providing adjustment means in a waveguide that guides high-frequency waves to a surface wave exciter that propagates a surface wave and matching according to the amount of food, the maximum power of the oscillation source can be input to the food.

[0003] Patent Document 2 provides a matching section having a microstrip line configuration with a change in impedance between a surface wave propagation line that propagates a surface wave and a transmission section that transmits high-frequency power to the surface wave propagation line, and cancels the reflected wave from the surface wave transmission line, so that high-frequency power can be efficiently transmitted.

[0004] Patent Document 3 states that by changing the height of the strip-shaped upright pieces in a predetermined region of a plurality of strip-shaped upright pieces that generate a surface wave, the surface wave generation intensity can be adjusted according to the food, and optimal heating can be performed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, as described in Patent Document 1, even if matching is achieved by the adjustment means of the waveguide, there is still high-frequency power radiated other than the surface wave line further ahead, and heating by the surface wave line cannot be maximized.

[0007] Furthermore, as described in Patent Document 2, even if a matching section is provided between the surface wave propagation line and the transmission section, mismatches caused by food placed in the middle of the surface wave propagation line cannot be resolved, resulting in radiation at that location and preventing the maximization of food heating. Moreover, since the matching section is placed in series between the surface wave propagation line and the transmission section, the propagation distance to the surface wave propagation line becomes longer, which increases spatial radiation.

[0008] Furthermore, as described in Patent Document 3, if an optimal surface wave line is to be prepared for each food product, a large quantity of surface wave lines would be required to accommodate a wide variety of foods, and there is a risk of misuse, making it unsuitable for practical use.

[0009] This disclosure provides a high-frequency heating device that ensures compatibility with a wide variety of foods and maximizes the heating of food by surface wave lines. [Means for solving the problem]

[0010] In order to solve the aforementioned conventional problems, The high-frequency heating apparatus in this disclosure is Surface wave propagation lines and A power supply unit that supplies high-frequency power to the surface wave line, It comprises a coupling portion that connects the surface wave line and the power supply unit, By providing at least one matching portion between the aforementioned coupling portion and the end of the surface wave line, The surface wave-shaped wires ensure alignment at a position suitable for maximizing food heating, and enable heating of a wide variety of objects to be heated to the desired state. [Effects of the Invention]

[0011] The high-frequency heating apparatus disclosed herein is The matching section can be arranged at an optimal position to maximize the heating of food by the surface wave line. Since matching can be ensured at a position close to a point where mismatch occurs in the surface wave line such as the food installation position and the power feeding point, unnecessary radiation and reflection can be minimized, and the heating of food by the surface wave line can be maximized.

Brief Description of the Drawings

[0012] [Figure 1] Schematic front view of the high-frequency heating device according to Embodiment 1 of the present invention [Figure 2] Explanation diagram of the mismatch position of the surface wave line [Figure 3] Schematic perspective view of the connection of the matching section according to Embodiment 1 of the present invention [Figure 4] Explanation diagram of the flow path of the high-frequency current in the surface wave line [Figure 5] Schematic plan view of the surface wave line according to Embodiment 2 of the present invention [Figure 6] Schematic perspective view of the surface wave line according to Embodiment 3 of the present invention [Figure 7] Schematic perspective view of the connection of the matching section according to other embodiments of the present invention

Modes for Carrying Out the Invention

[0013] (Findings etc. on which the present disclosure is based) When the inventors arrived at the idea of the present disclosure, the technology of propagating high-frequency power by surface waves and heating food was a situation where it was known as a technology for burning food.

[0014] Under such circumstances, the inventors found that at a plurality of mismatch points in the high-frequency propagation process of the surface wave line for burning food using surface waves, a lot of radiation, reflected power, etc. occur, but matching aims to maximize the propagation power by minimizing the reflected wave at the matching position, and the matching at the subsequent mismatch positions hardly contributes. In order to solve this problem, the inventors have come to form the main theme of the present disclosure that it is desirable to ensure matching for each mismatch position.

[0015] Therefore, the present disclosure A surface wave line that propagates a surface wave, A power feeding unit that supplies high-frequency power to the surface wave line, A coupling unit that couples the surface wave line and the power feeding unit, and provided is a high-frequency heating device having at least one matching unit provided between the coupling unit and the end of the surface wave line.

[0016] Hereinafter, embodiments will be described in detail with reference to the drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of matters already well known, or a redundant description of substantially the same configuration may be omitted. This is to avoid making the following description overly redundant and to facilitate understanding by those skilled in the art.

[0017] Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0018] (Embodiment 1) Hereinafter, Embodiment 1 will be described using FIGS. 1 to 4.

[0019] ​Figure 1 shows a schematic configuration diagram of a high-frequency heating device according to Embodiment 1 of the present invention. The object to be heated 2 is placed on a mounting platform 3 inside a heating chamber 1 surrounded by metal walls and heated. High-frequency power is supplied from a high-frequency power generation unit 4, such as a magnetron or a semiconductor oscillator, to a power supply unit 6 via a waveguide 5. The power supply unit 6 is connected to a surface wave transmission line 7 at a coupling unit 10 and transmits the high-frequency power. The surface wave transmission line 7 propagates the high-frequency power received at the coupling unit 10 in the form of surface waves to the termination unit 8. For example, as shown in Figure 3, the surface wave transmission line 7 has a configuration in which multiple metal plate-shaped stub-shaped conductors 12 are arranged on the upper side of a metal plate-shaped base conductor 11. By optimizing the height, width, spacing, and thickness of the multiple arranged stub-shaped conductors 12, surface waves can be formed that propagate along the surface wave transmission line without radiating high-frequency power. The high-frequency power in the form of surface waves propagating along the surface wave transmission line 7 strongly heats the object to be heated 2 placed nearby, causing it to char. A radiating section 14 is connected to the terminal section 8. The radiating section 14 has, for example, a rod-shaped antenna shape, and its length is set to approximately λ / 4 so that it resonates in the operating frequency band and has high radiation efficiency. It is coupled near the base conductor 11 where the high-frequency current is maximum, and radiates the high-frequency power that reaches the terminal section 8 into the heating chamber 1, heating the object to be heated 2 from the space above. The radiating section 14 is connected in series with the terminal section 8 of the surface wave line 7 and is arranged to extend upward into the space above. The surface wave line 7 may be installed so as to be rotatable with the power supply section 6 as its central axis.

[0020] Figure 2 shows an explanatory diagram of the mismatch locations in the surface wave transmission line. The high-frequency power 20 supplied from the power supply unit 6 propagates towards the terminal end 8 of the surface wave transmission line 7 via the path shown by the dotted line in Figure 2. Mismatch mainly occurs where the impedance of the high-frequency power propagation path changes abruptly. The main mismatch locations along this radio wave path are the dotted line position A at the coupling unit 10 where the power supply unit 6 switches to the surface wave transmission line 7, the dotted line position B at the mounting end of the object to be heated 2 on the mounting base 3, and the dotted line position C at the terminal end 8 of the surface wave transmission line 7. To maximize the heating of the object to be heated 2, it is necessary to ensure matching at least at positions A and B, which the high-frequency power passes through before reaching the object to be heated 2. When heating one object to be heated 2, it is usually placed in the center, so in such cases, positions A and B often coincide at the same coupling point. Considering this case, at least one matching unit is installed between the coupling unit 10 and the terminal end 8 of the surface wave transmission line 7.

[0021] Figure 3 shows a schematic configuration diagram of the matching section connection in Embodiment 1 of the present invention. Matching section 9a is installed at position A of the coupling section 10 described in Figure 2, that is, the coupling section where the power supply section 6 switches to the surface wave line 7, and matching section 9b is installed at position B of the end of the heated object 2 on the mounting base 3 (this position may vary depending on where the heated object is placed) to ensure matching. Furthermore, regarding the matching section 9b installed at position B, which varies depending on where the heated object is placed, for example, a frame for indicating where the heated object should be placed should be visually displayed on the mounting base 3, and when the heated object is placed accordingly, the matching section 9b should be able to match to the end of the heated object 2. Alternatively, the matching section 9b may be configured to be movable as needed. Note that if matching sections 9a and 9b are installed on the heated object side of the surface wave line 7, they may interfere with the surface waves and cause discharge, making installation difficult. Therefore, it is preferable to place them on the base conductor 11 side of the surface wave line 7. The surface wave line 7 has a configuration in which multiple stub-shaped conductors 12 are arranged on the upper side of a metal plate-shaped base conductor 11. The matching sections 9a and 9b are plate-shaped tabs, with one end connected to the base conductor 11. They branch off from the end of the high-frequency power 20 flow path and the surface wave line 7 described in Figure 2, extending in a direction approximately perpendicular to it, with the other end open. The length from the connected end to the open end of the plate-shaped tab is preferably one wavelength or less, and the width is preferably half a wavelength or less. As an example, Figure 3 shows the matching section 9a with the connected end as 92a and the open end as 91a.

[0022] By arranging the components in this way, it is not necessary to unnecessarily extend the power supply distance or insert transmission components with different performance characteristics in the middle of the surface wave transmission line 7 in order to cancel out reflected waves from the surface wave transmission line and efficiently transmit high-frequency power, thus ensuring optimal matching while maintaining the original performance. This is possible. Furthermore, the material of the matching section 9 only needs to be able to create the intended impedance at the intended location in the high-frequency transmission path, and metals such as aluminum are mainly used.

[0023] Figure 4 shows an explanatory diagram of the flow path of high-frequency current in a surface wave transmission line. It shows an example of the instantaneous distribution of high-frequency current 21 flowing through the base conductor 11 and stub-shaped conductor 12 that constitute the surface wave transmission line 7. The high-frequency current 21 flows from one end of a stub-shaped conductor 12 through the base conductor 11 to the other end of a stub-shaped conductor 12. Matching sections 9a and 9b are installed with one end connected to the flow path of the high-frequency current 21. The surface wave transmission line 7 propagates high-frequency power in the form of surface waves through the interaction of the high-frequency current 21 and the electric field (not shown) generated at the tip of the stub-shaped conductor 12. When the object to be heated 2 is placed near the tip of the stub-shaped conductor 12, it affects the nearby electric field, and this change affects the high-frequency current 21. Therefore, even if the matching section 9b is installed on the base conductor 11, which is far from the stub-shaped conductor 12 and the mounting base 3, it will exhibit a matching effect as long as it is on the flow path of the high-frequency current 21.

[0024] As explained in Figure 2, the impedance changes are different at positions A and B. At position A, the power supply section 6, which has the same configuration as a coaxial line, switches to a surface wave line 7. At position B, it is the same surface wave line 7, but the impedance of the heated object 2 is added at the termination section 8. Thus, the performance required of the matching section to ensure matching differs depending on the installation position. For this reason, as shown in Figure 3, matching sections 9a and 9b have different shapes, with their widths and lengths adjusted to achieve the required performance for each. In detail, the length of the matching section is considered as the L component; increasing the length of the matching section increases the L value, and shortening it decreases it. Also, the area is considered as the C component with respect to the bottom wall surface; increasing the area increases the C value, and narrowing it decreases it. By adjusting the LC components in this way, the required impedance is achieved. For example, matching section 9a is set to a length La and width Wa that can ensure matching between the power supply section 6 and the surface wave line 7. Furthermore, the matching section 9b is set to a length Lb and width Wb such that it can ensure matching between the power supply section 6 side and the heated object 2 side of the surface wave line 7. Thus, the shape of the matching section 9 varies depending on the impedance values ​​of each of the mismatched objects, and the shape is not limited. This is not an example; as long as the intended impedance is created near the mismatch location and reflection due to the mismatch is minimized, the thickness and shape of the matching section may be changed in addition to the length and width, or multiple components such as dielectrics may be combined.

[0025] As shown in Figure 2, the high-frequency power 20 propagates in two directions via the surface wave line 7. Although the left half is omitted in Figure 3, a matching section is similarly installed in the high-frequency power channel that branches off to the left of the surface wave line 7, ensuring optimal matching for each high-frequency power channel. Furthermore, the coupling section 10 is located at a common mismatch point where the left and right high-frequency power channels overlap, and matching can be ensured for both high-frequency power channels simultaneously by the matching section 9a.

[0026] Since the matching sections 9a and 9b are fixed at one end to the base conductor 11 of the surface corrugated line 7 and have their other ends open, when the surface corrugated line 7 rotates around the coupling section 10 as an axis, they can rotate together in sync and maintain their matching function at any angle.

[0027] Here, we have mainly described an example in which the object to be heated 2 is placed between the coupling portion 10 and the terminal portion 8 of the surface corrugated line 7. However, as mentioned above, when heating one object to be heated 2, it is usually placed in the center. In such a case, since positions A and B overlap at the same coupling point, one matching portion 9 is sufficient. An example of this configuration is shown in Figure 7 as another embodiment.

[0028] As explained above, by installing at least one matching section 9 (9a in the figure) between the coupling section 10 and the end of the surface wave line 7, matching can be ensured at the location where mismatch occurs, and the heating treatment of the object to be heated 2 by the surface wave can be maximized.

[0029] (Embodiment 2) Embodiment 2 will be described below with reference to Figure 5.

[0030] Figure 5 shows a schematic configuration diagram of the surface wave transmission line of Embodiment 2 of the present invention, viewed from above. In Figure 5, the surface wave transmission line 7 branches in two directions, upward and downward, from the connection point 10 with the power supply unit 6 toward the termination points 8a and 8b. The base conductor 11 constituting the surface wave transmission line 7 is V-shaped and divided into two branches. The stub-shaped conductor 12 branches into another conductor from the branching point. The flow path of the high-frequency power 20 also branches in two directions from the branching point, similar to the stub-shaped conductor 12. The main mismatch locations along this radio wave path are the location of the connection point 10, the branching point of the surface wave transmission line 7, the location of the heated object installation end, and the locations of the surface wave transmission line 7 termination points 8a and 8b. To maximize the heating of the heated object 2, it is desirable to ensure matching at the branching point of the surface wave transmission line 7 and the location of the heated object installation end. In Embodiment 2 of this disclosure, for each of the above-mentioned mismatch locations, a matching section 9c is provided at the position of the heated object installation end, and a matching section 9d is provided at the branching position of the surface wave line 7. However, if the branching position of the surface wave line 7 and the position of the heated object installation end are close together, only the matching section 9d may be installed for each path collectively.

[0031] If the surface wave line 7 is configured asymmetrically with respect to the power supply unit 6, it can be difficult to maintain horizontality, and unwanted forces may be applied, causing problems with rotation. Therefore, the matching unit 9c is positioned in a direction that balances it with respect to the power supply unit 6.

[0032] Furthermore, the matching section 9c has a tapered shape on the side that connects to the high-frequency power 20 flow path, narrowing the connection point to a limited range and ensuring a secure matching position.

[0033] (Embodiment 3) Embodiment 3 will be described below with reference to Figure 6.

[0034] Figure 6 shows a schematic configuration diagram of a surface wave transmission line according to Embodiment 3 of the present invention. The surface wave transmission line 7 has a matching section 9e installed between the coupling section 10 with the power supply section 6 and the terminal section. The matching section 9e is mechanically non-contact and electrically capacitively coupled to the underside of the base conductor 11 of the surface wave transmission line 7 via an insulator 13. The matching section 9e is mechanically fixed to the insulator 13, but the insulator 13 is held so as to be movable along the underside of the base conductor 11 of the surface wave transmission line 7, so the coupling position can be moved as needed, and matching can be ensured at the optimal position depending on the position of the object to be heated. At this time, the position of the object to be heated may be detected by an imaging unit or sensor, and furthermore, the high-frequency heating device may be configured to automatically move the matching section 9e to an arbitrary position as a result of the position detection. The insulator 13 may be made of Teflon (registered trademark), for example.

[0035] (effect) As described above, in this embodiment, the high-frequency heating device comprises a surface wave transmission line 7, a power supply unit 6, and a coupling unit 10. The surface wave transmission line 7 propagates high-frequency power as a surface wave. At least one matching unit 9 is installed between the coupling unit 10 and the terminal end 8 of the surface wave transmission line 7. This ensures matching at the optimal position near where mismatch occurs, maximizing heating of food by surface waves, and thus enabling heating of a wide variety of objects to be heated to a desired state.

[0036] As in this embodiment, the high-frequency heating device may have a matching unit 9 positioned in a direction that branches off from the flow path of the high-frequency power 20 propagating from the power supply unit 6 to the terminal end 8 of the surface wave line 7. This eliminates the need to extend the power supply distance unnecessarily or to insert transmission components with different performance in the middle of the surface wave line 7, ensuring optimal matching while maintaining the original performance, and enabling heating treatment of a wide variety of objects to be heated to the desired state.

[0037] As in this embodiment, the high-frequency heating device is connected in series with the terminal portion 8 of the surface wave line 7 It may also include a radiating section that is connected and positioned to extend into the space above. This suppresses reflection from the terminal section 8 of the surface wave line 7, ensuring that the matching effect of the matching section 9 functions reliably, allowing the surface wave line 7 to perform as designed and enabling efficient heating of the object to be heated. Furthermore, by minimizing reflection from the terminal section 8, the generation of standing waves on the surface wave line 7 can be suppressed, improving uneven heating.

[0038] As in this embodiment, the high-frequency heating device may also have a matching unit 9 connected to the flow path of the high-frequency current 21 of the surface wave transmission line 7. This ensures matching with the high-frequency power 20 propagating in the form of surface waves, thereby maximizing heating by surface waves.

[0039] As in this embodiment, the high-frequency heating device may connect a matching unit 9 to the base conductor 11 of the surface wave transmission line 7. This ensures matching with the high-frequency power 20 propagating in the form of surface waves, thereby maximizing heating by surface waves.

[0040] As in this embodiment, the high-frequency heating device may also have matching sections 9a and 9b positioned at the food placement locations of the coupling section 10 and / or the surface wave path 7. This ensures matching performance near locations where mismatch occurs in the surface wave propagation path, thereby maximizing heating by surface waves.

[0041] As in this embodiment, the high-frequency heating device may have matching units 9d for each flow path of the high-frequency power 20 propagating from the power supply unit 6 to the terminal end 8 of the surface wave line 7. This ensures matching performance near locations where mismatches occur in the surface wave propagation path, and maximizes heating by surface waves.

[0042] As in this embodiment, the high-frequency heating device may have a matching unit 9a installed at a position where the flow paths of the high-frequency power 20 overlap. This ensures matching in a unified manner, reduces the number of parts, and allows for lighter and more cost-effective antennas.

[0043] As in this embodiment, the high-frequency heating device may have a matching unit 9 installed at the coupling section 10 where the flow paths of the high-frequency power 20 overlap. This ensures matching in a unified manner, reduces the number of parts, and allows for lighter and more cost-effective antennas.

[0044] As in this embodiment, the high-frequency heating device may have a matching section 9 in the shape of a plate-like tab, with one end connected to the flow path of the high-frequency power 20 and the other end left open. This eliminates the need to extend the power supply distance unnecessarily or to insert transmission components with different performance in the middle of the surface wave line 7, ensuring optimal matching while maintaining the original performance, and thus enabling heating treatment of a wide variety of objects to be heated to the desired state.

[0045] As in this embodiment, the high-frequency heating device may have the matching section 9 positioned at an angle to the high-frequency power 20 flow path. This eliminates the need to extend the power supply distance unnecessarily or to insert transmission components with different performance characteristics in the middle of the surface wave line 7, ensuring optimal matching while maintaining the original performance, and enabling heating treatment of a wide variety of objects to be heated to the desired state.

[0046] As in this embodiment, the high-frequency heating device may adjust the width and length of the plate shape of the matching section 9. This ensures reliable matching performance and allows for heating of a wide variety of objects to be heated to the desired state.

[0047] As in this embodiment, the high-frequency heating device may have a tapered shape on the side of the matching section 9 that connects to the flow path of the high-frequency power 20. This allows the matching area to be narrowed down to a limited range, ensuring reliable matching performance and enabling heating of a wide variety of objects to be heated to the desired state. It can be processed.

[0048] As in this embodiment, the high-frequency heating device may electrically connect the matching unit 9 to the flow path of the high-frequency power 20 without mechanically making direct contact with the surface wave line 7, and the connection position between the matching unit 9 and the surface wave line 7 may be movable. This ensures reliable matching performance even in inconsistent mismatch positions, such as the food placement position, and allows for heating of a wide variety of objects to be heated to a desired state.

[0049] As in this embodiment, the high-frequency heating device may fix the matching section 9 to the surface wave line 7 via an insulator 13. This ensures reliable matching performance even at inconsistent misalignment positions, such as the food placement position, and allows for heating of a wide variety of objects to be heated to the desired state.

[0050] As in this embodiment, the high-frequency heating device is configured to rotate the surface wave line 7 around the power supply unit 6 as its central axis, and the matching unit 9 may rotate in synchronization with the surface wave line 7. This allows the matching function to be maintained at any angle, and enables heating treatment to a desired state for a wide variety of objects to be heated.

[0051] As in this embodiment, the high-frequency heating device may be equipped with a matching section 9 to improve the weight balance of the surface wave line 7 with respect to the power supply section 6. This facilitates the rotational movement of the surface wave line 7 and allows for heating of a wide variety of objects to be heated to a desired state. [Industrial applicability]

[0052] As described above, this disclosure can maximize heating by surface waves with a simple structure and is therefore applicable to cooking appliances such as high-frequency heaters. [Explanation of symbols]

[0053] 1 Heating chamber 2 Object to be heated 3. Mounting platform 4. High-frequency power generation unit 5 Waveguide 6 Power supply section 7. Surface wave track 8 Termination section 8a Termination section 8b Termination section 9 Matching section 9a Matching part 9b Matching part 9c Matching part 9d Matching part 9e Matching part 10 Joint 11. Foundation conductor 12 Stub-shaped conductors 13 Insulators 14 Radiation section 20 High-frequency power 21 High frequency current 91a Open end of matching section 9a 92a Connection end of matching section 9a

Claims

1. Surface wave propagation lines and A power supply unit that supplies high-frequency power to the surface wave line, It comprises a coupling portion that connects the surface wave line and the power supply unit, In a high-frequency heating apparatus having at least one matching section between the coupling section and the end of the surface wave path, The matching unit is positioned in a direction that branches off from the flow path of high-frequency power propagating from the power supply unit to the end of the surface wave line. High-frequency heating device.

2. A surface wave transmission line for propagating surface waves, A power supply unit that supplies high-frequency power to the surface wave line, It comprises a coupling portion that connects the surface wave line and the power supply unit, In a high-frequency heating apparatus having at least one matching section between the coupling section and the end of the surface wave path, If there are multiple high-frequency power transmission lines that propagate from the power supply unit to the end of the surface wave transmission line, the matching unit is provided at a position where the multiple high-frequency power transmission lines overlap. High-frequency heating device.

3. A surface wave transmission line for propagating surface waves, A power supply unit that supplies high-frequency power to the surface wave line, It comprises a coupling portion that connects the surface wave line and the power supply unit, In a high-frequency heating apparatus having at least one matching section between the coupling section and the end of the surface wave path, A matching section is provided between the coupling section and the end of the surface wave line. The matching portion has a plate-like tab shape, with one end connected to a high-frequency power channel and the other end open. High-frequency heating device.

4. A surface wave transmission line for propagating surface waves, A power supply unit that supplies high-frequency power to the surface wave line, It comprises a coupling portion that connects the surface wave line and the power supply unit, A matching section is provided between the coupling section and the end of the surface wave line. In a high-frequency heating apparatus having at least one matching section between the coupling section and the end of the surface wave path, The matching section does not mechanically make direct contact with the surface wave path, but is electrically connected to the high-frequency power path. The connection position between the matching section and the surface wave line is movable. High-frequency heating device.

5. The matching unit is arranged in a direction that branches off from the flow path of high-frequency power propagating from the power supply unit to the end of the surface wave line, A high-frequency heating apparatus according to any one of claims 2 to 4.

6. A radiating portion is connected in series with the terminal portion of the surface wave line and is arranged to extend toward the space above, A high-frequency heating apparatus according to any one of claims 1 to 4.

7. The matching unit is connected to the high-frequency current path of the surface wave line, A high-frequency heating apparatus according to any one of claims 1 to 4.

8. In the case where the surface wave line is configured to have a plurality of stub-shaped conductors arranged on a base conductor, the matching section is connected to the base conductor, A high-frequency heating apparatus according to claim 7.

9. The matching portion is positioned at the food placement location of the coupling portion and / or the surface wave line. A high-frequency heating apparatus according to claim 1.

10. When there are multiple transmission lines for the high-frequency power that propagates from the power supply unit to the end of the surface wave transmission line, the matching unit is arranged for each high-frequency power transmission line of the surface wave transmission line. A high-frequency heating apparatus according to claim 1.

11. When there are multiple transmission lines for the high-frequency power that propagates from the power supply unit to the end of the surface wave transmission line, the matching portion is provided at the connection point with the power supply unit as the position where the multiple high-frequency power transmission lines overlap. The high-frequency heating apparatus according to claim 2.

12. The matching section is arranged at an angle to the high-frequency power path of the surface wave line. A high-frequency heating apparatus according to claim 3.

13. Multiple matching sections are provided, and the width and length of the plate shape are adjusted according to the installation position. A high-frequency heating apparatus according to claim 3.

14. The matching portion is provided with a tapered shape on the side that connects to the surface wave line. A high-frequency heating apparatus according to claim 3.

15. The matching portion is fixed to the surface wave line via an insulator. A high-frequency heating apparatus according to claim 4.

16. The surface wave line is configured to rotate around the power supply unit as its central axis, and the matching unit rotates in synchronization with the surface wave line. A high-frequency heating apparatus according to claim 1.

17. If the surface wave line is arranged asymmetrically with respect to the power supply unit, the matching unit is installed in a direction that improves the weight balance with respect to the power supply unit. A high-frequency heating apparatus according to claim 16.

18. A surface wave transmission line for propagating surface waves, A power supply unit that supplies high-frequency power to the surface wave line, It comprises a coupling portion that connects the surface wave line and the power supply unit, In a high-frequency heating apparatus having at least one matching section between the coupling section and the end of the surface wave path, The surface wave line is configured to rotate around the power supply unit as its central axis. The matching unit is Rotates in sync with the aforementioned surface wave line, The power supply unit is installed in a manner that improves the weight balance. High-frequency heating device.

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