JP4133906B2 - Coaxial / waveguide conversion structure manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a coaxial-waveguide transition structure.

  Conventionally, for example, a coaxial mode transmission line 1a and a waveguide mode transmission line 1b as shown in FIG. 1 have been used as transmission lines for transmitting high-frequency signals. Here, the coaxial mode transmission line 1a is a transmission line having a structure in which the periphery of the central conductor 2 is surrounded by a circular pipe-shaped peripheral conductor 3a as shown in FIG. A dielectric 4a is provided between the conductor 3a and the surrounding conductor 3a. At this time, the surrounding conductor 3a may be configured to partially surround the periphery in addition to the structure surrounding the entire circumference of the center conductor 2. The waveguide mode transmission line 1b is a transmission line composed of a pipe-shaped peripheral conductor 3b having a cross-sectional shape such as a rectangular shape, for example, and a dielectric 4b is provided inside the peripheral conductor 3b. The surrounding conductor 3b is configured in a ground potential state. At this time, the surrounding conductor 3b may use a structure in which conductors are intermittently arranged at intervals smaller than the wavelength of a signal to be transmitted, in addition to a continuous pipe-like structure. A dielectric material is usually used for the dielectrics 4a and 4b.

  In general, in a wireless module that transmits and receives information by radio waves, there are many combinations that use a coaxial mode transmission path as a transmission path of an antenna that performs transmission or reception and use a waveguide mode transmission path as a transmission path of a signal of the wireless module. It is used. Therefore, for example, a configuration of a coaxial / waveguide converter as shown in FIG. 1B has been used at the connection portion between the coaxial mode transmission path on the antenna side and the waveguide mode transmission path on the wireless module side. It was. That is, the coaxial mode transmission line 1a and the waveguide mode transmission line 1b are coupled so as to be orthogonal to each other, and the central conductor 2 of the coaxial mode transmission line 1a is placed in the dielectric 4b of the waveguide mode transmission line 1b to a predetermined length. It is the structure arrange | positioned so that only length L may protrude.

  In the configuration of the coaxial / waveguide converter as shown in FIG. 1B, the length L of the protruding portion of the central conductor 2 of the coaxial mode transmission line 1a according to the design matters of the waveguide mode transmission line 1b. Therefore, there is a big problem in manufacturing from the point of mass productivity. In particular, when drilling a predetermined depth in the dielectric 4b of the waveguide mode transmission line 1b with a drill or the like, for example, since the tip of a processing tool such as a drill is usually formed in a tapered shape, the depth of the drilling There is a problem that it is difficult to adjust the protrusion depth of the center conductor 2 to a predetermined depth even if the tip of the center conductor 2 is finished with high accuracy.

The present invention aims to view the above problems, to provide a method of manufacturing a coaxial mode transmission line and the waveguide mode transmission line accurately and easily connectable coaxial-waveguide transition structure And

  In order to achieve such an object, according to the present invention, a plurality of dielectric members having at least one through hole are stacked and the through hole is exposed at least on the first surface side. A first step of forming a multilayer body; a first surface of the multilayer body excluding the periphery of the through hole; a second surface opposite to the first surface; and a conductor provided in the through hole. A coaxial mode transmission line in which a central conductor is connected to a conductor in the through hole and a conductor provided on the first surface and the second surface as a peripheral conductor. A method of manufacturing a coaxial / waveguide conversion structure, wherein a conversion structure with a wave tube mode transmission line is formed. According to such a manufacturing method, the through hole is formed in the dielectric having a thickness corresponding to the depth of the central conductor protruding from the coaxial mode transmission line to the waveguide mode transmission line, and the conductor is provided in the through hole. Thus, the length of the central conductor from the coaxial mode transmission line can be realized with high accuracy and ease.

  The first step may include a step of laminating a first dielectric member having a through hole and a second dielectric member having no through hole. The first step may include a step of laminating a plurality of dielectric members having through holes so that the through holes are arranged in a row and have a predetermined depth as a whole. it can.

  In the coaxial / waveguide conversion structure of the present invention, conductors are provided on the first surface and the second surface of the laminate, and this constitutes the surrounding conductor of the waveguide mode transmission line. Various things are possible. For example, a conductor provided on the side of the laminate, or a through hole provided at a pitch shorter than the wavelength of the transmitted radio wave is arranged in a pattern that assumes the side wall of the waveguide mode transmission line, and the conductor is provided in the inside. The so-called plug wall (plug wall waveguide) filled with can be obtained.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the coaxial-waveguide conversion structure which can connect a coaxial mode transmission line and a waveguide mode transmission line with high precision and easily is realizable.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  First, Embodiment 1 of the present invention will be described in detail with reference to the drawings. FIG. 2 is a flowchart showing a method of manufacturing the coaxial / waveguide conversion structure according to the first embodiment. The manufacturing method of the coaxial / waveguide conversion structure according to the first embodiment includes a waveguide dielectric laminating step (step S1), a surrounding conductor forming step (step S2), and a coaxial mode coupling step (step S3). It is configured.

  In the waveguide dielectric laminating step (step S1), a dielectric such as polytetrafluoroethylene filled in the waveguide mode transmission line is laminated, and the projecting portion of the central conductor of the coaxial mode transmission line described above Is a step of forming holes in a portion corresponding to the above, and details thereof will be described later. The surrounding conductor forming step (step S2) is a step of forming the surrounding conductor constituting the waveguide around the dielectric formed in step S1, and details thereof will be described later. The coaxial mode coupling step is a step of coupling the coaxial mode transmission path to the waveguide mode transmission path formed in step S2, and details thereof will be described later. Through these steps, it becomes possible to manufacture a coaxial / waveguide converter including the cross-sectional shape of a predetermined waveguide mode transmission path and the protruding length of the center conductor of the predetermined coaxial mode transmission path. .

  Next, the details of the waveguide dielectric laminating process shown in FIG. 2 will be described with reference to the drawings. FIG. 3 is a cross-sectional view showing the procedure of the waveguide dielectric laminating step. In the waveguide dielectric laminating step, as shown in FIG. 3A, a first dielectric member 11a having a thickness t1 and a second dielectric member 11b having a thickness t2 are laminated to form a laminate 11. Form. The first dielectric member 11a and the second dielectric member 11b are made of the same resin material such as polytetrafluoroethylene, and the thickness t2 of the second dielectric member 11b is the same as that shown in FIG. This corresponds to the length L of the protruding portion of the center conductor 2 of the mode transmission line 1a. A through hole 12 having a diameter corresponding to the diameter of the central conductor of the coaxial mode transmission line is formed in the second dielectric member 11b. By laminating the first dielectric member 11a and the second dielectric member 11b in this way, the multilayer body 11 having an apparent thickness (t1 + t2) and a depth of the protrusion hole from the upper surface t2 is obtained. It can be formed with high accuracy. Further, as shown in FIG. 3B, for example, a plurality of dielectric layers such as dielectric members 11c, 11d, and 11e in which a through hole having a diameter corresponding to the diameter of the central conductor of the coaxial mode transmission line is formed. It may be configured to obtain a desired thickness t2 by stacking. This is particularly effective when mass-producing a dielectric having a predetermined thickness with high accuracy.

  Next, details of the surrounding conductor forming step shown in FIG. 2 will be described with reference to the drawings. FIG. 4 is a cross-sectional view of the waveguide mode transmission line 10 formed by the surrounding conductor forming step. In the surrounding conductor forming step, a conductor 13 such as a copper alloy is formed on the surface of the laminate 11 manufactured in the waveguide dielectric laminating step. The conductor 13 is formed with a predetermined thickness around the multilayer body 11 by a method such as plating, and at this time, the conductor 13b is also formed in the through hole 12 provided in the second dielectric member 11b. By executing such a process, it is possible to easily obtain a structure in which a conductor having a predetermined depth is provided in the multilayer body 11 of the waveguide mode transmission line 10 with a high accuracy.

  Next, details of the coaxial mode coupling process shown in FIG. 2 will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing a procedure for attaching the coaxial mode transmission line 20 to the waveguide mode transmission line 10 formed by the surrounding conductor forming step. In the coaxial mode coupling step, first, as shown in FIG. 5A, on the upper surface of the waveguide mode transmission line 10 manufactured in the surrounding conductor forming step, that is, on the side where the through hole 12 and the conductor 13b are formed. Then, the surrounding conductor 13 in the region corresponding to the cross section of the dielectric 22 of the coaxial mode transmission line 20 with the conductor 13b as the center is removed. Subsequently, the coaxial mode transmission path 20 is attached so as to fit in the region. At this time, the surrounding conductor 21 at the attachment side end of the coaxial mode transmission line 20 is removed in advance from the attachment side end by an amount corresponding to the thickness of the surrounding conductor 13 of the waveguide mode transmission line 10. The surrounding conductor 13 of the wave tube mode transmission path 10 and the surrounding conductor 21 of the coaxial mode transmission path 20 are fixed by a method such as brazing or bonding, for example. Further, as shown in FIG. 5B, the central conductor 23 of the coaxial mode transmission line 20 is in electrical contact with the conductor 13b provided in the waveguide when coupled to the waveguide mode transmission line 10. To do. As a result, the waveguide mode transmission line 10 and the coaxial mode transmission line 20 are apparently coupled to each other, and the central conductor 23 of the coaxial mode transmission line 20 is placed in the laminated body 11 of the waveguide mode transmission line 10 in a predetermined manner. It is possible to form the coaxial / waveguide conversion structure 30 protruding with high precision by the depth.

  In addition, the coaxial mode transmission line 20 shown in FIG. 5 normally uses a coaxial cable or the like, but may be formed by stacking structures having the structure of the coaxial mode transmission line.

  By performing the steps as described above, according to the manufacturing method of the coaxial / waveguide conversion structure according to the first embodiment, from the coaxial mode transmission line to the waveguide mode transmission line in the waveguide dielectric laminating step. A through-hole is provided in a dielectric having a thickness corresponding to the depth of the protruding central conductor, and a conductor is stacked in the through-hole in the surrounding conductor forming process, and the conductor and the central conductor are electrically connected in the coaxial mode coupling process. By connecting so as to connect to the coaxial mode transmission line, a coaxial / waveguide change structure in which the central conductor from the coaxial mode transmission line protrudes to a predetermined depth of the waveguide mode transmission line can be realized with high accuracy and easily. .

  Next, an application example of the coaxial / waveguide conversion structure according to the first embodiment will be described with reference to the drawings. 6 shows a coaxial / waveguide conversion structure 40 including a planar antenna 41. FIG. 6 (a) is a plan view, and FIG. 6 (b) is a cross-sectional view taken along a line passing through the center of the coaxial mode transmission line. is there. The coaxial / waveguide conversion structure 40 is a planar substrate, and has a structure in which conductors 40a and 40b are laminated on the upper and lower surfaces of a dielectric, as shown in FIG. 6B. A planar antenna 41 is formed on a part of the conductor 40a. A waveguide 43 surrounded by a wall member 42 is formed inside the coaxial / waveguide conversion structure 40. The waveguide 43 is a closed space surrounded by the wall member 42 and the upper and lower conductors 40a and 40b, and has a structure in which radio waves or signals input to the inside do not leak to the outside. The wall member 42 is a conductor electrically connected to the conductors 40a and 40b, and the conductors are intermittently arranged at intervals smaller than the wavelength of the signal to be transmitted or the structure formed continuously as shown in FIG. The structure to do may be sufficient.

  The coaxial / waveguide conversion structure 40 is arranged so that a coaxial mode transmission line 44 is coupled to a part of the waveguide 43 described above. The coupling portion between the waveguide 43 and the coaxial mode transmission line 44 is formed by the method of manufacturing the coaxial / waveguide conversion structure according to the first embodiment as shown in FIGS. A radio wave signal transmitted or received from the planar antenna 41 is guided to the central conductor 45 of the coaxial mode transmission path 44 via the waveguide 43 and input / output to / from an external device (not shown) by the coaxial mode transmission path 44. The

  From the above embodiments, according to the present invention, a method for manufacturing a coaxial / waveguide conversion structure capable of easily connecting a coaxial mode transmission line and a waveguide mode transmission line with high accuracy and a manufacturing method using the same. A coaxial / waveguide conversion structure can be realized.

  The embodiment described above is only one of the best modes for carrying out the present invention, and the present invention can be implemented with various changes and modifications without departing from the gist thereof.

It is a figure which shows the outline of a general coaxial mode transmission path and a waveguide mode transmission path, and the structure of the coaxial-waveguide converter in a prior art. It is a flowchart which shows the manufacturing method of the coaxial-waveguide conversion structure in Example 1 of this invention. FIG. 3 is a cross-sectional view showing a procedure of a waveguide dielectric laminating process shown in FIG. 2. It is sectional drawing of the waveguide mode transmission line 10 formed by the surrounding conductor formation process shown by FIG. It is sectional drawing which shows the procedure which attaches the coaxial mode transmission path 20 to the waveguide mode transmission path 10 formed by the surrounding conductor formation process shown by FIG. 6 shows a coaxial / waveguide conversion structure 40 including a planar antenna 41, which is an application example of the coaxial / waveguide conversion structure according to the first embodiment. FIG. 6 (a) is a plan view, and FIG. 6 (b) is a plan view. It is sectional drawing by the line which passes along the center of a coaxial mode transmission line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Waveguide mode transmission path 11, 11a, 11b, 11c, 11d, 11e Dielectric 12 Through-hole 13 Ambient conductor 20, 44 Coaxial mode transmission path 21 Ambient conductor 23, 45 Center conductor 40 Coaxial / waveguide conversion structure 41 Planar antenna 42 Wall member 43 Waveguide L Predetermined depth of protrusion of central conductor t1 Thickness of first dielectric t2 Thickness of second dielectric

Claims (3)

A first step of laminating a plurality of dielectric members having at least one through-hole to form a laminate in which the through-hole is exposed at least on the first surface side;
A second step of providing a conductor in the through hole, and the first surface of the laminate excluding the periphery of the through hole, the second surface opposite to the first surface, and
A coaxial mode transmission line in which a central conductor is connected to a conductor in the through hole, and a waveguide mode transmission line provided with conductors provided on the first surface and the second surface as surrounding conductors. A method of manufacturing a coaxial / waveguide conversion structure, characterized in that a conversion structure is formed.   The coaxial / waveguide according to claim 1, wherein the first step includes a step of laminating a first dielectric member having a through hole and a second dielectric member having no through hole. Manufacturing method of tube conversion structure. The first step includes a step of laminating a plurality of dielectric members having through holes so that the through holes are arranged in a row and have a predetermined depth as a whole. A method for producing a coaxial / waveguide conversion structure according to claim 1.

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