JP2001267838A - Method of manufacturing waveguide antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a waveguide antenna having stability even with time lapse without lowering the original performance of the waveguide antenna by using plastic material for a bottom part coated with a conductive layer on its surface in order to reduce the weight of the antenna. SOLUTION: In the method of manufacturing the waveguide antenna integrally forming an antenna part and a feeding part on a bottom part by assembling the bottom part and a cover, constituting the bottom part of plastic forming a conductive layer on a face constituting a waveguide and a distribution waveguide and constituting the antenna part and the cover of the feeding part of a metallic thin plate forming plural slots on the antenna part, a low melting point metal is arranged on a junction face between the bottom part, and the cover and the metal is welded and joined by depressing a heating substance having high heat-responsiveness onto the surface of the cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a waveguide antenna.

[0002]

2. Description of the Related Art FIG. 13 is an explanatory view of a generally known waveguide antenna.
It consists of 32. The antenna section 31 has a structure in which a slot 34 for transmitting or receiving a radio wave is provided in a waveguide 33. The power supply unit 32 transmits a signal to be transmitted to the antenna unit 31.
And a function of collecting signals received by the antenna unit 31.

On the other hand, JP-A-3-7406 and JP-A-3-3406
No. 65805 describes a waveguide antenna obtained by improving the above-mentioned waveguide antenna. The waveguide antennas described in these publications have an antenna unit 35 as shown in FIG.
The waveguide 36 that constitutes the bottom part 38 provided with the groove 37 and the slot
The cover 38 is provided with a cover 39, and the bottom portion 38 and the cover 40 are bonded together with a conductive adhesive 41, or assembled by screwing, fitting, or the like. In addition, it is described that the power supply unit is similarly configured with a bottom and a lid and assembled. Furthermore, it is described that a plastic material is used at the bottom. In this case, a structure in which a groove serving as a waveguide is formed in the plastic material, a conductor layer is provided on the surface on which the groove is formed, and a lid is assembled is described. Have been.

The waveguide antenna assembled and manufactured as described above is different from a conventional general waveguide in that
It has the advantage of being easy to machine for forming the waveguide and increasing the processing accuracy, and in the case of using a plastic material for the bottom, in addition to the above-mentioned advantages, it has the advantage of being able to achieve weight reduction, but the bottom and the lid are separated. The electrical resistance of the joint does not become sufficiently low if it is joined by using a conductive adhesive or mechanical means such as screwing and fitting, and stable electrical power is obtained by mechanical means such as screwing and fitting. For example, there is a problem that the inherent performance as a waveguide antenna is not obtained, or the stability over time is lacking.

[0005]

SUMMARY OF THE INVENTION The present invention focuses on a plastic material and a bottom provided with a conductive layer on the surface thereof, which can reduce the weight of the waveguide antenna, and uses this bottom as a waveguide antenna. It is an object of the present invention to manufacture a waveguide antenna which does not impair its original performance and has stability over time.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies and studies. as a result,
Conventionally, there is a waveguide antenna in which the bottom and the lid are made of a metal conductor, which are joined using a brazing material.The antenna (A) joined using this brazing material is an antenna joined using a conductive adhesive. Note that the antenna gain is higher than that shown in FIG. However, it has been found that there is a problem that the plastic is melted or deformed under the influence of heat at the time of brazing in the plastic material having the bottom portion and the conductive layer provided on the surface thereof. The present invention has been made to solve such a problem.

That is, according to the present invention (claim 1), an antenna unit and a power supply unit are integrally provided at the bottom by assembling a bottom and a lid, and the bottom constitutes a waveguide and a distribution waveguide. A method of manufacturing a waveguide antenna comprising a plastic sheet provided with a conductor layer, and a cover for the antenna section and the feeding section formed of a thin metal plate having a plurality of slots provided in the antenna section. A method of manufacturing a waveguide antenna, comprising: interposing a low-melting-point metal between the joining surfaces of the above, and pressing and melting a low-melting-point metal by pressing a heating object having high thermal response from above a lid. Things.

In the present invention, a low melting point metal (including an alloy) such as tin, indium, solder, wood metal or the like is interposed between the joining surfaces of the bottom and the lid, and the low melting point metal is melted by heating. And the lid are joined, so that the thermal effect on the plastic that constitutes the bottom part is reduced and good joining can be performed, and thus the waveguide has stable performance over time without impairing the original performance An antenna can be manufactured.
Nevertheless, raising the temperature of the entire bottom to a temperature at which the low melting point metal is melted has no risk of melting or deforming the plastic. In other words, it is necessary to reliably melt only the low melting point metal without affecting the bottom plastic. Therefore, in the present invention, a heating object having a high thermal response is pressed from above the lid as a heating means to heat and melt the low melting point metal. By using a heating object with high thermal responsiveness, the rise and fall time of the temperature of the heating object itself can be controlled quickly, and by pressing the heating object from above the lid, the low melting point metal is passed through the thin metal plate that constitutes the lid. It is possible to quickly control the temperature rise and fall time. Therefore, the temperature of the heating object can be raised and the temperature can be lowered immediately after reaching the temperature at which the low melting point metal melts. In this way, since the heat input can be stopped immediately after the low-melting-point metal is melted, the low-melting-point metal can be reliably melted without substantially affecting the bottom plastic. Further, after the low-melting-point metal is melted, the low-melting-point metal may be pressed by a pressing means different from the heating object until the molten low-melting-point metal is solidified.

The heating object having a high thermal response can be a ceramic heating element.

Next, according to a second aspect of the present invention, a bottom and a lid are assembled, an antenna unit and a feed unit are provided integrally at the bottom, and the bottom constitutes a waveguide and a distribution waveguide. A waveguide made of a thin metal plate having a plurality of slots provided in the antenna portion and a lid of the antenna portion and the feeding portion, or a laminated body of the thin metal plate and a transparent dielectric material. In the method for manufacturing an antenna, a low-melting-point metal is interposed between the bonding surfaces of the bottom and the lid, and the low-melting-point metal is irradiated with light energy and melted and bonded while the lid is pressed against the bottom. A method for manufacturing a waveguide antenna, which is a feature of the present invention.

In the present invention (claim 2), a low melting point metal (including an alloy) such as tin, indium, solder or wood metal is interposed between the joining surfaces of the bottom and the lid. Since the bottom and lid are joined by heating and melting, the effect of heat on the plastic that constitutes the bottom is reduced and good bonding can be performed, thereby maintaining the original performance and stability over time. A waveguide antenna having a good quality can be manufactured. Further, in the present invention, light energy irradiation is employed as a heating means for reliably melting only the low melting point metal without thermally affecting the plastic at the bottom. Light energy irradiation has very good controllability because the input heat quantity can be controlled by the energy density of light and irradiation time, and when no irradiation is performed, no heat is input. Therefore, in the present invention, the heat input after the low-melting-point metal is melted can be quickly stopped by controlling and irradiating the input heat amount of light energy in accordance with conditions such as the melting temperature of the low-melting-point metal. The low-melting-point metal can be reliably melted with almost no thermal effect.

Further, even if a material transparent to light is placed in the light path for irradiating light energy, there is no absorption of light there and there is no influence on the generation of heat. Therefore, if the lid is pressed against the bottom with such a transparent object, the low melting point metal can be heated and melted with the lid pressed against the bottom without disturbing the heat input of light energy. If a transparent plastic is used for forming the bottom, light energy can be applied from the bottom side. Further, by making the lid a laminated body of a transparent dielectric and a metal thin plate, the metal thin plate is made as thin as possible, so that irradiation using light energy effectively can be performed.

Next, according to a third aspect of the present invention, an antenna unit and a feed unit are integrally provided at the bottom by assembling a bottom and a lid, and the bottom constitutes a waveguide and a distribution waveguide. A waveguide made of a thin metal plate having a plurality of slots provided in the antenna portion and a lid of the antenna portion and the feeding portion, or a laminated body of the thin metal plate and a transparent dielectric material. In the method for manufacturing an antenna, a low-melting-point metal is interposed between the joining surfaces of the bottom and the lid, and the low-melting-point metal is melted by induction heating and joined while the lid is pressed against the bottom. 6 is a method for manufacturing a waveguide antenna.

In the present invention (claim 3), a low-melting metal (including an alloy) such as tin, indium, solder, or wood metal is interposed between the joining surfaces of the bottom and the lid, and the low-melting metal is used. Since the bottom and lid are joined by heating and melting, the effect of heat on the plastic that constitutes the bottom is reduced and good bonding can be performed, thereby maintaining the original performance and stability over time. A waveguide antenna having a good quality can be manufactured. Further, in the present invention, induction heating is employed as a heating means for reliably melting only the low melting point metal without affecting the plastic at the bottom. The principle of induction heating is well known. When an alternating current is passed through a coil to approach a conductor, magnetic lines of force generated by the coil penetrate the metal body, and the magnetic lines change according to a change in the alternating current. At that time, a current is induced in the conductor so as to cancel the change of the magnetic field lines, and this is called an induced current. The induced current flows through the conductor, causing a resistance loss in the conductor and generating heat. The characteristic of this induction heating is that it acts only on conductors and does not act on dielectrics such as plastics. In addition, the coil used for heating does not need to be in contact with conductors, and heat energy is only applied while current is flowing through the coil. Input is easy to control the heat input. Therefore,
In the present invention, the heat input by induction heating is controlled according to conditions such as the melting temperature of the low-melting-point metal, and the heat-input can be stopped immediately after the low-melting-point metal is melted. The low-melting-point metal can be reliably melted without affecting the heat.

As described above, the induction heating does not act on the dielectric. Therefore, if the lid is pressed against the bottom with such a dielectric, the low melting point metal can be heated and melted with the lid pressed against the bottom without disturbing the heat input of the induction heating. The plastic forming the bottom is a dielectric, and can be heated from the bottom side. Further, the lid is made of a laminated body of a dielectric and a metal thin plate, and the thin metal plate is made as thin as possible, so that the heating using the induction heating can be effectively performed.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a waveguide antenna manufactured by applying the method of manufacturing a waveguide antenna according to the present invention, and FIG. It is a partial explanatory view showing a manufacturing state of the waveguide antenna in the case where it is located.

The waveguide antenna 1 is manufactured by joining a lid 5 of the feed section 2 and a lid 6 of the antenna section 3 to a bottom 4 having the feed section 2 and the antenna section 3 integrally with a low melting point metal 7. You. The lid 5 and the lid 6 may be integrated, or may be divided and separated.

The bottom portion 4 is composed of a plate-shaped plastic material 8 and a metal layer 9 provided on the surface thereof. The feeding portion 2 serves as a distribution waveguide, and the antenna portion 3 serves as a waveguide. 10 and 11 are provided respectively. Power supply unit 2
The lid 5 of the antenna unit 3 is a thin metal plate, and the lid 6 of the antenna unit 3 is a slot 12.
It is composed of a thin metal plate provided with.

As for the method of joining the lid 5 (or the lid 6) to the bottom 4 with the low-melting metal 7, as shown in FIG. 2, the low-melting metal is placed between the bottom 4 and the lid 5 (or the lid 6). In a state in which the ceramic heating element 7 is provided, the ceramic heating element 13 having good thermal responsiveness is pressed and set on the lid 5 (or the lid 6). And
After this, the ceramic heating element 13 is energized,
13 is heated, and the low-melting-point metal 7 is melted and joined by the heat. In this joining, the energization is stopped immediately after the low-melting metal 7 is melted. As a result, the temperature of the ceramic heating element 13 having good thermal responsiveness rapidly decreases, and the molten low-melting-point metal 7 is quickly solidified and joined. After the solidification, the ceramic heating element 13 is retracted to release the pressing. FIG.
Shows an example of the profile of the temperature change of the ceramic heating element 13, and it can be seen that the temperature can be quickly increased and decreased as shown in the figure.

In the method of manufacturing the waveguide antenna 1 by the above-described bonding, the thermal effect on the plastic material 8 constituting the bottom portion 4 is reduced, and good bonding can be performed without melting or deforming the plastic material 8. In addition, this makes it possible to obtain the waveguide antenna 1 having the original performance and the stability over time.

FIG. 4 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention. In the joining method shown in FIG. 4, the bottom 4 and the lid 5 (or the lid 6) are described. ) With the low-melting-point metal 7 provided therebetween, and the lid 5 (or the lid 6).
The pressing tool 14 is pressed from above and set, and the ceramic heating element 13 having good thermal response is set adjacent to the pressing tool 14. After that, the ceramic heating element 13 is energized to heat the ceramic heating element 13, and the low-melting metal 7 is melted and joined by the heat.
In this joining, the energization is stopped immediately after the low-melting metal 7 is melted. As a result, the temperature of the ceramic heating element 13 having good thermal responsiveness rapidly decreases, and the molten low melting metal 7
Quickly solidifies and can be joined. Pressing tool after solidification 14
To release the pressing.

Also in the method of manufacturing the waveguide antenna 1 by the bonding shown in FIG. 4 as described above, the thermal effect on the plastic material 8 constituting the bottom portion 4 is reduced, and good bonding without melting or deforming the plastic material 8 is achieved. Can be performed. In addition, this makes it possible to obtain the waveguide antenna 1 having the original performance and the stability over time.

FIG. 5 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention. In the joining method shown in FIG. 5, the bottom 4 and the lid 5 (or the lid 6) are described. ) With the low-melting-point metal 7 provided therebetween, and the lid 5 (or the lid 6).
A ceramic heating element with better thermal responsiveness than the side surface of the low melting metal 7 while pressing the pressing tool 15 from above
13 is set by touching. After that, the ceramic heating element 13 is energized to heat the ceramic heating element 13, and the low-melting metal 7 is melted and joined by the heat. In this joining, the energization is stopped immediately after the low-melting metal 7 is melted. As a result, the ceramic heating element 13 with good thermal response
In this case, the temperature immediately drops, and the molten low-melting metal 7 solidifies quickly and can be joined. After the solidification, the pressing tool 15 is retracted to release the pressing. Note that this method is applied to the joining of the peripheral portion of the waveguide antenna.

In the method of manufacturing the waveguide antenna 1 by the bonding shown in FIG. 5 as described above, the thermal effect on the plastic material 8 constituting the bottom portion 4 is reduced, and the bonding is performed without melting or deforming the plastic material 8. Can be performed. In addition, this makes it possible to obtain the waveguide antenna 1 having the original performance and the stability over time.

FIG. 6 is a partial explanatory view showing the manufacturing state of another example of the waveguide antenna according to the present invention. In the joining method shown in FIG. 6, the bottom 4 and the lid 5 (or the lid 6) are described. ) With the low-melting-point metal 7 provided therebetween, and the lid 5 (or the lid 6).
A transparent resin pressing tool (hereinafter, referred to as a transparent pressing tool) 16 is pressed from above and set, and a light energy irradiation device (illustrated by a condensing lens 17 and a heating light beam 18) is placed above the transparent pressing tool 16. Is set.)
After that, the light energy irradiating apparatus is started, the heating light beam 18 is condensed by the condensing lens 17, and the low melting point metal 7 is melted and joined by the heat generated by the light energy. In this joining, the light energy irradiation device is stopped immediately after the low melting point metal 7 is melted. Thereby, the irradiation of the light energy is stopped immediately, and the molten low melting point metal 7 is quickly solidified and joined. Transparent pressing tool after solidification
16 is retracted to release the pressing. The light source of the light energy irradiation device is not particularly limited, but may be of any type as long as sufficient light energy can be obtained, such as a laser or a halogen lamp. When light energy is used, the lid 5 (or the lid 6) may be a laminate of a thin metal plate and a transparent dielectric. In addition, the transparent pressing tool 16 may be a transparent object such as a transparent glass or the like in addition to a transparent resin.

Also in the method of manufacturing the waveguide antenna 1 by the bonding shown in FIG. 6 as described above, the thermal effect on the plastic material 8 constituting the bottom portion 4 is reduced, and good bonding without melting or deforming the plastic material 8 is achieved. Can be performed. In addition, this makes it possible to obtain the waveguide antenna 1 having the original performance and the stability over time.

In the method shown in FIG. 6, an example using a solid transparent pressing tool 16 has been described. However, as shown in FIG.
A hollow transparent pressing tool 19 may be used. In this case, the heating light beam 18 from the light energy irradiation device is pressed.
Since 19 does not absorb and attenuate, it need not be a transparent substance.

FIG. 8 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention. In the joining method shown in FIG. 8, the plastic material 8 constituting the bottom 4 is used. A transparent plastic material 20 is adopted, and with the low melting point metal 7 provided between the bottom 4 and the lid 5 (or the lid 6), the pressing tool 21 is pressed from above the lid 5 (or the lid 6) and set. Meanwhile, a light energy irradiation device (illustrated by a condenser lens 22 and a heating light beam 23) is set below the bottom portion 4. Then, after this, the light energy irradiation device is started, and the heating light beam 23 is focused by the focusing lens 22,
The low-melting point metal 7 is melted and joined by the heat generated by the light energy. In this joining, the light energy irradiation device is stopped immediately after the low melting point metal 7 is melted. Thereby, the irradiation of the light energy is stopped immediately, and the molten low melting point metal 7 is quickly solidified and joined. After the solidification, the pressing tool 21 is retracted to release the pressing.

Also in the method of manufacturing the waveguide antenna 1 by the bonding shown in FIG. 8 as described above, the thermal effect on the transparent plastic material 20 constituting the bottom portion 4 is reduced, so that the plastic material 20 can be favorably melted or deformed. Joining can be performed. In addition, this makes it possible to obtain the waveguide antenna 1 having the original performance and the stability over time.

In the method shown in FIGS. 6 and 7, when a transparent plastic material is used as the plastic material 8 constituting the bottom portion 4, as shown by a two-dot chain line in FIG. A light energy irradiation device (illustrated by a condenser lens 22 and a heating light beam 23) can be set and used together.

FIG. 9 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention. In the joining method shown in FIG. ), The low-melting metal 7 is provided between the induction heating coil 24
And the induction heating device 26 having the coil container 25 are set by pressing the lid 5 (or the lid 6) from above. Thereafter, an alternating current is applied to the induction heating coil 24 to melt and join the low melting point metal 7 by induction heating. In this joint,
Immediately after the low melting point metal 7 is melted, the energization is stopped. As a result, the temperature of the induction heating coil 24 rapidly decreases, and the molten low-melting-point metal 7 is quickly solidified and joined. After the solidification, the induction heating device 26 is retracted to release the pressing. Needless to say, the coil container 25 is made of a dielectric material so that the container itself is not heated.

In the method of manufacturing the waveguide antenna 1 by the bonding shown in FIG. 9 as described above, the thermal effect on the plastic material 8 constituting the bottom portion 4 is reduced, and good bonding can be achieved without melting or deforming the plastic material 8. Can be performed. In addition, this makes it possible to obtain the waveguide antenna 1 having the original performance and the stability over time.

In the method shown in FIG.
The example in which the induction heating device 26 in which the coil 24 is housed in the coil container 25 is described, but the dielectric 27 may be placed on the lid 5 (or the lid 6) as shown in FIG. Or lid 5
Although the lid (or the lid 6) itself is not shown in the figure, it can be formed by a laminate of a metal thin plate and a dielectric, and the induction heating can be performed by pressing the induction heating coil 24 directly on the dielectric 27 or the dielectric. . Further, the plastic material 8 constituting the bottom part 4 is also a dielectric, and as shown in FIG.
Even if 26 is pressed from the lower surface of the plastic material 8 on the bottom 4, the low-melting metal 7 is melted by induction heating to join the lid 5 (or the lid 6) to the bottom 4, similarly to the method shown in FIG. 9. . Further, as shown in FIG. 12, the induction heating device 26 can be provided both above the lid 5 (or the lid 6) and below the bottom 4 to perform induction heating.

[0034]

As described above, according to the manufacturing method of the waveguide antenna according to the present invention, by using a heating object having a high thermal response, light energy or heating means such as induction heating, the bottom portion can be formed. Heating can be performed while reducing the thermal effect on the plastic material that constitutes the base plate, thereby melting or deforming the plastic that constitutes the bottom part, and forming a metal sheet that constitutes the antenna part and the feed part on the conductor layer provided on the bottom part Can be satisfactorily joined. In addition, this makes it possible to manufacture a waveguide antenna having the original performance and having stability over time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a waveguide antenna manufactured by applying a method of manufacturing a waveguide antenna according to the present invention.

FIG. 2 is a partial explanatory view showing a manufacturing state of a waveguide antenna when a heating object having a high thermal response according to the present invention is used.

FIG. 3 is a graph showing an example of a profile of a temperature change of the ceramic heating element according to the present invention.

FIG. 4 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 5 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 6 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 7 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 8 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 9 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 10 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 11 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 12 is a partial explanatory view showing a manufacturing state of another example of the waveguide antenna according to the present invention.

FIG. 13 is an explanatory view of a conventional waveguide antenna, in which a is a top view and b is a cross-sectional view along AA.

FIG. 14 is an explanatory view of another conventional waveguide antenna,
a is an exploded perspective view of the antenna section, and b is a cross-sectional view in the lateral direction.

FIG. 15 is a graph showing a comparison of antenna gain when the bottom and the lid are joined using a brazing filler metal and when the bottom and the lid are joined using a conductive adhesive.

[Explanation of symbols]

1: Waveguide antenna 2: Feeder
3: Antenna part 4: Bottom part 5: Cover of power supply part
6: Antenna cover 7: Low melting point metal 8: Plastic material
9: metal layer 10: groove serving as distribution waveguide 11: groove serving as waveguide 1
2: Slot 13: Ceramic heating element with good thermal response 1
4, 15: Pressing tool 16: Transparent resin pressing tool 1
7: Condensing lens 18: Heating light beam 19: Hollow transparent pressing tool 20: Transparent plastic material 21: Pressing tool 2
2: Condensing lens 23: Heating light beam 24: Induction heating coil 2
5: Coil container 26: Induction heater 27: Dielectric

[Procedure amendment]

[Submission date] March 30, 2000 (2003.3.3)
0)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG. 8

FIG. 9

FIG. 10

FIG. 11

FIG.

FIG. 13

FIG. 14

FIG.

Claims (3)

[Claims] An antenna and a feeder are integrally provided at the bottom by assembling a bottom and a lid, and the bottom is made of plastic having a conductor layer provided on a surface constituting a waveguide and a distribution waveguide. In the method for manufacturing a waveguide antenna, wherein the lid of the antenna section and the feed section is made of a thin metal plate having a plurality of slots provided in the antenna section, a low-melting metal is provided between the joining surface of the bottom section and the lid. A method for manufacturing a waveguide antenna, comprising: interposing an interposed member and pressing a heated object having high thermal response from a lid to melt and bond the low melting point metal. 2. A plastic in which a bottom and a lid are assembled to provide an antenna unit and a feed unit integrally at the bottom, and the bottom is provided with a conductor layer on a surface constituting a waveguide and a distribution waveguide. In the method for manufacturing a waveguide antenna, wherein the lid of the antenna unit and the feeding unit is made of a thin metal plate having a plurality of slots provided in the antenna unit, or a laminated body of the thin metal plate and a transparent dielectric, Manufacturing a waveguide antenna, wherein a low-melting-point metal is interposed between the joining surfaces with the lid, and the low-melting-point metal is irradiated with light energy and melted and joined while the lid is pressed against the bottom. Method. 3. A plastic in which a bottom and a lid are assembled and an antenna unit and a feed unit are integrally provided at the bottom, and the bottom is provided with a conductor layer on a surface constituting a waveguide and a distribution waveguide. In the method for manufacturing a waveguide antenna, wherein the lid of the antenna unit and the feeding unit is made of a thin metal plate having a plurality of slots provided in the antenna unit, or a laminated body of the thin metal plate and a transparent dielectric, A method for manufacturing a waveguide antenna, comprising: interposing a low-melting metal between bonding surfaces with the lid; and melting and bonding the low-melting metal by induction heating with the lid pressed against the bottom.