JP2013109887A - Microwave heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat an object to be heated efficiently and uniformly with a simple and compact structure, without using a table, an antenna, a rotation mechanism of a phase shifter, or the like.SOLUTION: A waveguide 100 transmitting microwaves generated by microwave generation means 50 to a heating chamber 200 can distribute a plurality of openings for radiating microwaves widely to the heating chamber 200, by widening the second width in a microwave radiation section. When the first width 101 at an inlet 110 for connection with the microwave generation means 50 is made narrower than a second width 102, a microwave heating device capable of heating an object to be heated uniformly with a compact and simple microwave power supply configuration, without using a rotation mechanism, can be provided.

Description

  The present invention relates to a microwave heating apparatus such as a microwave oven, and more particularly to a microwave heating apparatus characterized by the structure of a microwave power feeding unit.

  A typical microwave heating apparatus that heats an object to be heated with a microwave is a microwave oven. In the microwave oven, the microwave generated in the microwave supply means is radiated into the metal heating chamber, and the object to be heated in the heating chamber is heated by the radiated microwave.

  A magnetron is used as a microwave supply means in a conventional microwave oven. Microwaves generated by the magnetron are radiated into the heating chamber through the waveguide. If the electromagnetic field distribution of the microwave in the heating chamber is not uniform, the object to be heated cannot be heated by microwaves uniformly.

  As a means for uniformly heating the object to be heated, a structure for rotating the object to be heated by rotating a table on which the object to be heated is rotated, a structure for rotating an antenna for radiating microwaves while fixing the object to be heated, or A microwave heating apparatus having a structure in which the phase of the microwave generated from the microwave supply means is changed by a phase shifter has been common.

  For example, in a conventional microwave heating apparatus, a rotating antenna, an antenna shaft, and the like are arranged inside a waveguide. By driving a magnetron while rotating the rotating antenna by an antenna motor, the microwave distribution in the heating chamber is increased. Non-uniformity is reduced.

  Further, as described in Patent Document 1, a rotatable antenna is provided on the upper part of the magnetron, and the antenna is rotated by the wind of the blower fan by applying cooling air from the blower fan to the blades of the rotary antenna. There has been proposed a microwave heating apparatus that changes the microwave distribution in the heating chamber.

  On the other hand, as described in Patent Document 2 which reduces the uneven heating of the object to be heated by microwave heating and reduces the cost and saves the space of the power feeding unit, it simply radiates circularly polarized waves into the heating chamber. A microwave heating apparatus having a single microwave radiating portion has been proposed.

JP-A-62-64093 U.S. Pat. No. 4,301,347

  However, in the microwave heating apparatus such as the microwave oven having the above-described conventional configuration, it is required to efficiently heat an object to be heated with a simple structure as much as possible, and has been proposed so far. There were various problems with the structure.

In addition, microwave heating devices, particularly microwave ovens, have been developed for high-power technology, and a rated high-frequency output of 1000 W has been commercialized in Japan. Microwave ovens are notable for heating food by heat conduction, but the convenience of directly heating food using dielectric heating is a major feature of the product. The problem of non-uniform heating will become more apparent.

  The following two points can be cited as structural problems of the conventional microwave heating apparatus. The first point requires a mechanism for rotating the table or antenna in order to reduce non-uniform heating. Therefore, it is necessary to secure a rotation space and an installation space such as a motor for rotating the table or antenna. That was hindering the miniaturization of the range. The second point is that in order to stably rotate the table or antenna, it is necessary to provide the rotating antenna above or below the heating chamber, and the structure is limited.

  Installing a table or a phaser rotation mechanism in the microwave radiation chamber of the microwave heating device makes it difficult to ensure reliability, to achieve downsizing, and to reduce costs. Therefore, there is a demand for a microwave heating apparatus that does not require these mechanisms.

  Further, circularly polarized light is radiated into the heating chamber as described in Patent Document 2 which reduces the uneven heating of the object to be heated by microwave heating and reduces the cost and saves the space of the power feeding unit. The microwave heating device having a single microwave radiating part has the advantage of not having a rotation mechanism, but the problem is that sufficient uniform heating by microwave heating has not been realized, There is room for improvement.

  Here, in a method of rotating the object to be heated itself placed on a table with respect to a microwave radiation opening provided on one side of a conventional heating chamber, or a method of rotating the antenna to stir the microwave in the heating chamber In order to achieve uniform heating without using a rotating mechanism, it is effective to make microwaves directly incident on the object to be heated contained in the heating chamber in a wide range. It is important that a plurality of openings are appropriately and widely dispersed on the wall surface of the heating chamber, not as a single mouth.

  However, when the microwave radiation ports are appropriately dispersed and arranged so as to achieve the desired uniform heating, the waveguide (microwave transmission path) becomes large in order to secure the area, and the microwave A large space is required for the arrangement of the transmission path from the generating means to the microwave radiation section. In general, a microwave heating device is also equipped with a power supply and a cooling fan for the microwave generator. Some of them are equipped, and a space-saving and simple form is required for the microwave power supply configuration.

  The present invention solves the above-described problems, and an object thereof is to provide a microwave heating apparatus capable of uniformly heating an object to be heated without using a rotating mechanism.

  In order to solve the above-described conventional problems, a microwave heating apparatus according to the present invention includes a heating chamber that houses an object to be heated, a microwave generation unit that generates a microwave to be supplied to the heating chamber, and a microwave generation unit. A waveguide composed of a transmission line having a rectangular cross section, including an input section for connecting microwave generation means to transmit the generated microwave to the heating chamber, and a microwave radiation section having a plurality of openings connected to the heating chamber And the second width in the microwave radiation portion of the waveguide is larger than the first width in the input portion of the waveguide. Accordingly, microwaves can be emitted from the openings widely dispersed in a plurality of locations with respect to the object to be heated, so that the microwaves can be emitted to the entire object to be heated without being biased.

According to the present invention, the waveguide that transmits the microwave generated by the microwave generating means to the heating chamber heats the plurality of openings that radiate the microwave by widening the second width in the microwave radiating portion. A simple microwave power supply that can be widely dispersed in the chamber and saves space by using a first width smaller than the second width in the input section to which the microwave generating means is connected, without using a rotating mechanism. A microwave heating apparatus capable of uniformly heating an object to be heated with the structure can be provided.

  In other words, by arranging a plurality of openings for radiating microwaves in the microwave radiating section widely and appropriately, microwaves can be directly incident on a heated object accommodated in the heating chamber, and more than one The shape and size of the aperture can be set for each aperture so that appropriate radiation characteristics and radiation amount can be obtained, and the object to be heated can be effectively heated uniformly.

  Furthermore, since the waveguide for transmitting microwaves from the microwave generating means to the microwave radiating portion saves space by reducing the width of the input section connecting the microwave generating means, peripheral components Since the microwave radiation part can be arranged so that the energy of the microwave radiated to the heating chamber can be symmetrical with respect to the center of the heating chamber without being restricted by the heating chamber, depending on the position of the object to be heated in the heating chamber The heating state does not change.

  In addition, since the in-tube wavelength of the transmitted microwave changes due to the difference in the width between the input section of the waveguide and the microwave radiation section, the length between the input section and the microwave radiation section is set according to the relationship of the in-tube wavelength. In this case, the phase of the transmitted microwave can be adjusted appropriately according to the arrangement of the openings of the microwave radiating section to achieve a matching state with few reflected waves, thereby realizing high efficiency with uniformity. Therefore, it is possible to provide a microwave heating apparatus that is economical and easy to use.

1 is an external perspective view of a main part of a microwave heating apparatus according to Embodiment 1 of the present invention. The perspective view of the waveguide of the microwave heating device in Embodiment 1 of this invention The perspective view of the waveguide of the microwave heating device in Embodiment 2 of this invention The partial side view of the microwave heating apparatus of the state which removed the microwave generation means in Embodiment 3 of this invention Cross-sectional schematic diagram of relevant parts of a microwave heating apparatus according to Embodiment 4 of the present invention The perspective view of the waveguide of the microwave heating device in Embodiment 5 of this invention

  1st invention transmits the microwave which generate | occur | produces the heating chamber which accommodates to-be-heated material, the microwave generation means which generates the microwave supplied to the said heating chamber, and the said microwave generation means to the said heating chamber And a waveguide made of a transmission line having a rectangular cross section including an input section for connecting the microwave generating means and a microwave radiating section having a plurality of openings connected to the heating chamber. The microwave heating device has a second width in the microwave radiating portion of the tube larger than a first width in the input portion of the waveguide.

  In the present invention, a waveguide for transmitting microwaves generated by the microwave generating means to the heating chamber has a plurality of openings for radiating microwaves widened in the heating chamber by widening the second width of the microwave radiating section. The first width at the input section connecting the microwave generating means can be made smaller than the second width to save space and use a simple microwave power supply structure without using a rotation mechanism. A microwave heating apparatus that can uniformly heat a heated object can be provided.

  According to a second invention, in addition to the first invention, the second thickness of the microwave radiating portion of the waveguide is smaller than the first thickness of the input portion of the waveguide. is there.

  In addition to the effects of the first invention, the microwave heating apparatus of the present invention prevents the occurrence of sparks in the waveguide of the input section to which the microwave generating means is connected, and can further reduce the thickness of the microwave radiating section. It is possible to provide a microwave heating apparatus that is a space and can uniformly heat an object to be heated with a simple microwave feeding configuration without using a rotation mechanism.

  According to a third invention, in the first or second invention, the waveguide is configured such that a center of the first width in the input section is eccentric with respect to a center of the second width in the microwave radiation section. It is the microwave heating apparatus provided.

  According to the third aspect of the present invention, it is possible to provide a microwave heating apparatus that can heat an object to be heated uniformly with a simple microwave power supply configuration that is space-saving and does not use a rotation mechanism. That is, for example, the microwave radiating portion of the waveguide is disposed substantially at the center of the heating chamber, so that the symmetry of the energy distribution of the microwave in the heating chamber is ensured, so that the object to be heated of various shapes and amounts Can be heated to the desired state.

  Furthermore, since the input section connecting the microwave generating means can be selected at a position suitable for the arrangement of peripheral components, the microwave heating device can be used effectively by utilizing the space formed by decentering the width center of the waveguide. It can be efficiently and compactly configured.

  According to a fourth invention, in any one of the first to third inventions, the waveguide is bent from the microwave radiating portion along the wall surface constituting the heating chamber, and has the input portion. The microwave heating apparatus is provided with a section, and a sectional dimension changing section in which the sectional dimension of the waveguide gradually changes on the side section.

  Thereby, the waveguide is arranged by effectively using the wall surface of the heating chamber, and the input portion and the cross-sectional dimension changing portion are provided in a direction different from the formation direction of the microwave radiating portion. Can be provided so as to face a wide area of the wall surface of the heating chamber, so that a plurality of openings can be widely dispersed and suitably arranged. That is, it is possible to provide a microwave heating apparatus that is space-saving and that can uniformly heat an object to be heated with a simple microwave feeding configuration without using a rotation mechanism.

  According to a fifth invention, in any one of the first to fourth inventions, the opening connected to the heating chamber in the microwave radiating portion of the waveguide includes a micro shape including an opening shape that radiates circularly polarized waves. It is a wave heating device.

  As a result, microwaves whose electric field direction rotates and radiates from the openings that radiate circularly polarized waves and are radiated to the object to be heated, and it is possible to more effectively heat the object to be heated in combination with multiple openings. A microwave heating apparatus can be provided.

  According to a sixth invention, in any one of the first to fifth inventions, a plurality of openings connected to the heating chamber in the microwave radiation portion of the waveguide are provided in the first width direction. It is a microwave heating device.

  Thereby, the plurality of openings in the microwave radiating portion can be suitably arranged so that the microwaves are widely dispersed and radiated while ensuring the symmetry of the energy distribution of the microwaves radiated into the heating chamber. Therefore, it is possible to provide a microwave heating apparatus that is space-saving and capable of uniformly heating an object to be heated with a simple microwave power supply configuration without using a rotation mechanism.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a microwave heating apparatus according to the invention will be described with reference to the accompanying drawings. In addition, although the microwave oven is demonstrated in the microwave heating apparatus of the following embodiment. Further, the present invention is not limited to the specific configurations of the following embodiments, and configurations based on similar technical ideas are included in the present invention.

(Embodiment 1)
FIG. 1 is a schematic external view of a main part of a microwave heating apparatus according to Embodiment 1 of the present invention. In FIG. 1, 10 is an object to be heated, 200 is a heating chamber, 50 is a magnetron as a microwave generating means, and 100 is a waveguide. The heating chamber 200 is configured in a substantially rectangular parallelepiped shape with a wall surface made of a metal material that reflects microwaves and an opening / closing door 200d for taking in and out the object to be heated 10, and is configured to confine the supplied microwaves inside.

  FIG. 2 is a perspective view showing a configuration of waveguide 100 in a state where magnetron 50 and heating chamber 200 in Embodiment 1 are not connected. In FIG. 2, 110 h is a connection port of the magnetron 50 provided at the input unit 110 of the waveguide 100. Reference numeral 120 denotes a microwave radiating portion connected to the heating chamber 200 of the waveguide 100, and 120 h denotes a plurality of openings provided in the microwave radiating portion 120 for radiating microwaves to the heating chamber 200.

  Hereinafter, the operation of the microwave heating apparatus will be described. The article to be heated 10 is put in from an opening / closing door 200d provided on a part of the wall surface constituting the heating chamber 200 and placed on the mounting portion 201 in the heating chamber 200. The placement unit 201 is provided with a glass plate of a low dielectric loss material facing the wall surface to which the microwave radiation unit 120 is connected. When an instruction to start heating is given by the user, the microwave heating apparatus operates the magnetron 50 that is a microwave generating means, generates a microwave in the waveguide 100, and transmits the microwave to the microwave radiating unit 120. The object to be heated 10 is heated by being supplied to the heating chamber 200 from the opening 120h.

  Here, the waveguide 100 is configured by a transmission path having a rectangular cross section surrounded by a pair of width surfaces and a pair of thickness surfaces according to the magnetron 50 used in the microwave heating apparatus. In a general rectangular waveguide, the width a and thickness b of the waveguide are selected from the wavelength λ to be transmitted within the range of λ / 2 <a <λ and b <λ / 2. Thus, the data is transmitted in a form called TE10 mode. When the magnetron 50 oscillates at a frequency of 2450 MHz, since the wavelength λ is about 120 mm, the width surface dimension a is selected to be 70 to 110 mm, and the thickness surface dimension b is selected to be 15 to 40 mm.

  As shown in FIG. 2, the waveguide 100 of the present embodiment is configured such that the second width 102 in the microwave radiating section 120 is larger than the first width 101 in the input section 110 to which the magnetron 50 is connected. Specifically, in the present embodiment, the dimension of the first width 101 is set to 75 mm, whereas the second width 102 is set to 105 mm wider than the first width 101. In the microwave radiating unit 120, a plurality of openings 120 h that radiate microwaves into the heating chamber 200 can be dispersed in a wide range of the second width 102.

  As described above, in the present embodiment, the waveguide 100 is configured such that the second width 102 in the microwave radiating unit 120 is larger than the first width 101 in the input unit 110. In a conventional waveguide having a constant width dimension, a plurality of openings cannot be sufficiently dispersed and arranged due to the limitation of the width dimension, and uniform heating of an object to be heated cannot be realized. On the contrary, when the width of the waveguide is widened by giving priority to the arrangement, the entire waveguide becomes large, leading to an increase in the size of the microwave heating apparatus. On the other hand, in the microwave heating apparatus of the present invention, an object to be heated can be uniformly heated with a small and simple microwave feeding structure without using a rotating mechanism.

(Embodiment 2)
FIG. 3 is a perspective view of a waveguide of the microwave heating apparatus according to Embodiment 2 of the present invention. 3 is different from the first embodiment in that the second thickness 104 in the microwave radiating unit 120 is configured to be smaller than the first thickness 103 in the input unit 110 of the waveguide 100.

  In the input unit 110, an antenna (not shown) of the magnetron 50 is inserted into the connection port 110h. In order to secure the insulation distance between the antenna (not shown) of the magnetron 50 and the wall surface of the input section 110 of the waveguide 100 and prevent sparks, there are restrictions on reducing the first thickness 103. is there. In the present embodiment, the second thickness 104 of the waveguide in the microwave radiating unit 120 is configured to be thin while preventing the occurrence of sparks.

  In addition to the effects of the first embodiment, there is no more wasted space, and thus a microwave that can uniformly heat an object to be heated with a smaller and simpler microwave feeding structure without using a rotating mechanism. A heating device can be provided.

(Embodiment 3)
FIG. 4 is a partial side view of the microwave heating apparatus with the microwave generation means removed in Embodiment 3 of the present invention. In FIG. 4, 105 is the center of the first width 101, and 106 is the center of the second width. The difference from the first or second embodiment is that the center 105 of the first width in the input unit 110 is decentered by the eccentric 107 with respect to the center 106 of the second width in the microwave radiating unit 120 as shown in FIG. Is provided.

  According to the present embodiment, components attached to the microwave heating device (for example, a fan that cools the magnetron, a power source that drives the magnetron, a control unit that controls heating, etc.) are efficiently placed in the peripheral space formed by eccentricity. Can be arranged. In other words, the microwave radiating part can be arranged so as to avoid the parts arranged around the power supply structure and to ensure the symmetry of the microwave energy radiated to the heating chamber with respect to the center of the heating chamber. The heating state does not change greatly depending on the position of the object to be heated.

(Embodiment 4)
FIG. 5 is a schematic cross-sectional view of the relevant part of a microwave heating apparatus according to Embodiment 4 of the present invention.

  As shown in FIG. 5, the waveguide 100 is provided with a side portion 130 having an input portion 110 bent from the microwave radiating portion 120 along the wall surface constituting the heating chamber 200. In FIG. 5, the side portion 130 is formed with a cross-sectional dimension changing portion 135 in which the cross-sectional dimension of the waveguide 100 gradually changes.

  By providing a cross-section changing section 135 from the input section 110 toward the microwave radiating section 120 and gradually changing the width or thickness of the waveguide 100 or both the width and thickness, the micro wave transmitted through the waveguide can be transmitted. The waves can be efficiently supplied to the heating chamber 200 while preventing loss due to complicated reflection.

  Accordingly, it is possible to provide a microwave heating apparatus that can prevent a reduction in heating efficiency and can uniformly heat an object to be heated with a small and simple microwave power feeding configuration without using a rotation mechanism.

In addition, since the in-tube wavelength of the microwave transmitted through the cross-sectional dimension changing unit 135 changes due to the difference in width between the input unit 110 and the microwave radiating unit 120 of the waveguide 100, the input unit 110 and the microwave radiating unit 120. Similarly to the length, the transmission path length of the cross-sectional dimension changing portion 135 can be set by the relationship of the guide wavelength.

  That is, when the first width 101 is set to 75 mm, the in-tube wavelength in the input unit 110 is about 207 mm, and the in-tube wavelength in the microwave radiating unit 120 in which the second width is set to 105 mm is about 150 mm. Since the wavelength at 135 gradually changes from about 207 mm to about 150 mm, by adjusting the length of the cross-sectional dimension changing portion 135 and the position to be provided in the transmission direction without changing the overall length of the waveguide while keeping the arrangement of the magnetron 50 constant. The length of the transmission path between the input unit 110 and the microwave radiating unit 120 can be adjusted, and matching conditions with few reflected waves can be set in the connection with the heating chamber 200. In this case, the phase of the transmitted microwave can be made appropriate in accordance with the opening of the microwave radiating section to achieve a matching state with few reflected waves, and high efficiency can be realized with uniformity.

(Embodiment 5)
FIG. 6 is a perspective view of waveguide 100 of the microwave heating apparatus according to the fifth embodiment of the present invention. The difference from the first to fourth embodiments is that, as shown in FIG. 6, the opening 120h connected to the heating chamber 200 in the microwave radiating section 120 of the waveguide 100 includes an opening shape that radiates circularly polarized waves. . Furthermore, a plurality of openings 120 h are microwave heating devices provided in the second width 102 direction.

  In the present embodiment, the microwave radiating unit 120 is shaped to radiate circularly polarized waves as shown in FIG. Circular polarization is a technique widely used in the field of mobile communication and satellite communication. Examples of familiar use include an ETC (Electronic Toll Collection System) “non-stop automatic toll collection system” and the like.

  Circular polarization is a microwave in which the polarization plane of the electric field rotates with respect to the traveling direction of the radio wave, and when the circular polarization is formed, the direction of the electric field continues to change with time. The radiation angle of the emitted microwave has a feature that it keeps changing. Thereby, compared with the microwave heating by the linearly polarized wave used in the conventional microwave heating apparatus, the microwave is dispersed and radiated over a wide range so that the object to be heated can be microwave heated uniformly. become. In particular, there is a strong tendency for uniform heating in the circumferential direction of circular polarization. Note that circularly polarized waves are classified into two types, that is, right-handed polarization (CW: clockwise) and left-handed polarization (CCW: counterclockwise) from the direction of rotation, but there is no difference in heating performance.

  By utilizing the above feature and emitting circularly polarized microwaves through the opening 120h, the heating distribution in the heating chamber 200 can be made more uniform. In addition, as an opening shape for outputting circularly polarized waves from the opening 120h of the microwave radiating unit 120 provided in the waveguide 100, as shown in FIG. Two slots (apertures) having a width so as to be polarized are crossed at the center and inclined by 45 degrees with respect to the microwave transmission direction. Further, the first radiation in the microwave radiating unit 120 of the waveguide 100 is formed. A total of six openings 120 h are provided in three rows in the microwave transmission direction (the length direction of the waveguide 100) arranged in two rows across the width center 106.

  As described above, in the present embodiment, the microwaves 120 h of the microwave radiating unit 120 are shaped to radiate circularly polarized waves, so that the microwaves spread from the plurality of openings 120 h of the microwave radiating unit 120. Is radiated to the heating chamber, and the microwave radiation to the object to be heated 10 can be made uniform in a wider range. Further, by making the second width 102 wide in the microwave radiating section 120, the shape and size of the opening can be set for each opening so that an appropriate radiation characteristic and radiation amount can be obtained. Things can be heated uniformly.

  That is, by arranging the opening 120h in accordance with the phase of the microwave transmitted in the microwave radiating unit 120, it is possible to make the radiation direction of the microwave appropriate, and the amount of radiation is appropriately controlled by the size of the opening 120h. It is possible to make the microwave radiation characteristic appropriate depending on the shape of the opening, the transmission direction of the microwave and the arrangement angle of the opening 120h, so that the desired uniform heating can be performed according to the heating chamber to be connected. There is an effect that can be realized.

  In the present embodiment, the shape of the opening 120h of the microwave radiating portion 120 that radiates circularly polarized waves has been described with reference to the shape shown in FIG. 6, but the shape is not limited to that in FIG. Any shape that radiates can be used. Also, the present invention is not limited to the arrangement of the openings in this embodiment.

  As described above, the microwave heating apparatus of the present invention can uniformly irradiate an object to be heated, and further eliminates the need to provide a special movable part for supplying microwaves, so that it has high reliability and durability. Is also excellent. It can be effectively used in a microwave heating apparatus that performs heating processing and sterilization of food.

DESCRIPTION OF SYMBOLS 10 Object to be heated 50 Microwave generation means 100 Waveguide 101 First width 102 Second width 110 Input section 120 Microwave radiation section 120h Opening 200 Heating chamber

Claims (6)

A heating chamber for storing an object to be heated;
Microwave generation means for generating a microwave to be supplied to the heating chamber;
A rectangle including an input unit for connecting the microwave generation unit to transmit the microwave generated by the microwave generation unit to the heating chamber and a microwave radiation unit provided with a plurality of openings connected to the heating chamber. A waveguide composed of a transmission line having a cross section,
The microwave heating device, wherein a second width of the microwave radiating portion of the waveguide is larger than a first width of the input portion of the waveguide. The microwave heating device according to claim 1, wherein the second thickness of the microwave radiating portion of the waveguide is smaller than the first thickness of the input portion of the waveguide. 3. The microwave heating according to claim 1, wherein a center of the first width in the input portion is eccentrically provided with respect to a center of the second width in the microwave radiation portion in the waveguide. apparatus. The waveguide is provided with a side portion having the input portion bent from the microwave radiation portion along the wall surface constituting the heating chamber, and the sectional dimension of the waveguide gradually changes on the side portion. The microwave heating apparatus of any one of Claim 1 to 3 which comprised the cross-sectional dimension change part. The microwave heating device according to any one of claims 1 to 4, wherein an opening connected to the heating chamber in the microwave radiating portion of the waveguide includes an opening shape that radiates circularly polarized waves. 6. The microwave heating apparatus according to claim 1, wherein a plurality of openings connected to the heating chamber in the microwave radiating portion of the waveguide are provided in the first width direction. 7.

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