JPH0211167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a horn antenna integrated with a feeding waveguide, which constitutes an antenna (antenna) in combination with a parapet surface reflector.

2. Description of the Related Art Radio communication devices and locating devices that use extremely high frequency bands, that is, microwave to millimeter wave bands, use antennas at their input and output ends. In order to efficiently emit (transmit) and input (receive) extremely high frequency waves depending on the purpose, this antenna uses a rotating or two-dimensional rod surface reflector, a secondary antenna, and a second reflector. Some have a horn antenna as a primary antenna arranged in an aperture at the focal point.

That is, as shown in FIG. 9, a flange 21 of a feed waveguide 2 is attached to the center bottom of a rotating rod surface reflector (hereinafter simply referred to as a reflector) 1 and passes through the feed waveguide section. 22 consists of a U-shaped part 23 that hangs downwardly and is curved in a U-shape, a horizontal part 24, and a horn antenna part 25 that opens toward the center of the bottom of the reflector 1. The open end of the horn antenna section 25 is located at or near the focal point of the reflecting mirror 1, and coincides with the central axis of the reflecting mirror 1 to form an antenna. Note that the opening side of the reflecting mirror 1 is entirely covered and protected by a radome (not shown).

[Conventional technology]

The conventional feed waveguide and horn antenna section described above has a rectangular shape in which the waveguide 41 can be fitted into the center of the circular stepped flange 31, as shown in a partial perspective view in FIG. A hole 32 is bored, a waveguide 41 is inserted in the direction of the arrow, and the waveguide 41 is joined, for example, by silver brazing.

The waveguide 41 is integrated with a U-shaped portion, and as shown in FIG. 11, an end 45 of a horizontal portion 44 is open, and a horn antenna 5 is attached to this end.

In this horn antenna 5, the inner diameter of the end portion 51 that joins the end portion 45 is the same as a and b, and the opening side 5
The inner diameter of No. 2 is expanded to A and B and is tapered with a predetermined length L.

This figure is enlarged on all four sides, but the two facing
The other two surfaces may be parallel and are determined by design.

Such a horn antenna 5 is used in combination with the reflecting mirror 1 to obtain the most efficient and effective antenna radiation characteristics (antenna beam pattern).

Conventionally, the horn antenna 5 has been made by joining four inclined plates, by cutting the inner surface of a metal block or waveguide, or by precision casting. The connection to the electric waveguide has been either by direct connection, for example by brazing, or by providing flanges on both sides and screwing them together. Further, the rectangular hole 32 is provided in the flange 31 by a process such as broaching.

[Problem that the invention seeks to solve]

In the conventional structure described above, the rectangular hole 32 of the flange 31 is processed separately, and it is difficult to align the centers thereof, and the processing itself is troublesome. Since the horn antenna 5 is a separate body, it requires a lot of man-hours to manufacture, and it is also troublesome to connect it to the feed waveguide. If a feed waveguide is not reinforced with a stay or the like, a large vibration impact will generate stress at the base of the flange during transportation or movement.

[Means for solving problems]

In order to solve the above conventional problems, the present invention
A rectangular waveguide made by extrusion or drawing is bent into a U shape, a flange is attached to one end, and a horn forming mold is directly inserted into the other end to form a horn antenna. It's about doing.

[Effect]

According to the above-mentioned method, since the feeding waveguide and the horn antenna are integrated, manufacturing can be performed consistently, manufacturing time can be shortened, the product is suitable for mass production, and the product is stable in size, shape, and quality. can get.

[Example] Examples of the method of the present invention will be specifically described below with reference to the drawings.

FIG. 2 is a side view of a waveguide section according to an embodiment of the present invention, in which the horizontal portion where the horn antenna section 61 is to be formed, the U-shaped curved section 62, the inclined section 63, and the flange attachment section 64 are horizontal. It is formed on the same axis as the horn antenna section 61. A drawn waveguide made of straight red copper material is annealed, and the inside is filled with laminated thin plates or filled with sand or low-melting point soft metal, and then fitted into a bending die and accurately formed into the desired shape using a press, etc. .

The above filler is necessary to prevent deformation when the bending radius is small compared to the waveguide cross section, but it is not always necessary when the bending radius is large enough and the deformation due to bending is within an allowable range. It is not necessary.

The second figure shows the state in which the mold was removed from the mold and the filling material was removed. Note that the wide side of the rectangular waveguide is the illustrated surface, and the narrow side is the curved surface.

Next, the horn antenna section 61 is formed, and its supporting mold is shown separately in FIG. The support mold 7 consists of a main mold 71 and a sub-mold 72, and the main mold 71
A horn antenna part 73 and a curved part 74 are continuously and precisely formed in a concave groove with an upward opening on one side, and the above-mentioned waveguide is adapted to the horn antenna part 61.
The end surfaces of the end portions coincide with each other, and the flange attachment portion 64 protrudes upward.

The horn antenna groove 73 is formed into three slopes that widen upward, and a pair of screw holes 75 and a pair of guide pin holes 76 are provided on both sides of the outer surface.

The sub mold 72 has a recess 77 that expands upward to just cover the horn antenna recess 73, and a pair of screw insertion holes 78 and a pair of guide pins 79 are implanted on both sides of the recess 77.

With the above, the waveguide is fitted into the main mold 71 and received, and the sub mold 7
Install 2. Guide pin 7 in guide pin hole 76
When 9 is fitted, the relationship between the two is accurately determined, and the two opposing surfaces each have a tapered shape so that the horn antenna part is configured with an inner surface in the shape of a truncated pyramid.
A parallel gap can be seen between the waveguide and the outer shape of the waveguide. A bolt (not shown) is inserted into the screw insertion hole 78, screwed into the screw hole 75, and tightened to make it immovable.

As shown in FIG. 4, the horn shape forming mold (referred to as mold) 8 has a main trunk 81 with a rectangular cross section that can be inserted exactly into the inner shape of the waveguide, and a wedge-shaped tapered shape that expands upward from the lower edge in the middle part. A horn forming mold part 82 is formed.

The lower end is chamfered 83 to facilitate insertion into the waveguide.

When the mold 8 is inserted from below into the horn antenna forming part 61 of the waveguide supported by the support mold 7, the lower end of the horn forming mold part 82 abuts against the inner end. Avoiding the flange attachment part 64, press the mold 8 downward with a press device or the like using appropriate means to form the horn antenna forming part 6.
1 is expanded and plastically deformed. Eventually, the outer shape matches the funnel shape formed by the horn antenna part groove 73 and the recess 77, and the inner shape matches the horn forming mold part 82 and comes into close contact with it.

This can be done smoothly without displacement because the waveguide is fitted into the groove of the main mold 71 and is held and supported by the sub mold 72, and because the waveguide is blunted.

The mold 8 is removed and the horn antenna section 61 removed from the support mold is shown in FIG. 5 as viewed from the open end side. As is clear from the figure, a horn antenna portion 61 having a desired shape is integrally formed from a waveguide, and the inner surface is continuous with a preferable electrical plane.

As shown in the partial side cross-section of FIG. 6, when the enlarged outer shape portion (indicated by the chain line) of the horn antenna section 61 is removed to match the outer shape of the waveguide section, the periphery of the opening end surface becomes thin. . This helps eliminate end face flange effects on electromagnetic waves. After checking the dimensions and shape of the horn antenna part 61, make corrections as necessary, and process the flange mounting part 64 into a circular shape from a position with a predetermined dimension C based on the end face 61' as shown in FIG. do. This processing uses a jig and lathe processing to ensure that the center is accurately aligned with the center of the waveguide. As shown in the E-E cross section of FIG. 7, the outer periphery of the narrow side is circular, and the wide side remains mostly parallel, with a diameter of D.

Figure 8a shows the flange attachment. The stepped circular flange 9 has a hole 91 with an inner diameter D in the center and a step 9 in the middle.
2. It consists of a reflecting mirror mounting surface 93.

The circularly processed portion of the flange attachment portion 64 of the waveguide is fitted and inserted into the hole 91, and the stepped portions are brought into contact with each other. Note that prior to fitting, the square tube 95 is inserted into the rectangular portion of the waveguide. The hole 91 and the circular processing portion are rotatable.

In this way, the three parts are joined together, for example, by silver brazing.

Thereafter, the end face 96 of the flange 9 shown in FIG. 8b
Then, a portion of the waveguide (indicated by a chain line) protruding from this end face 96 is finished by cutting. That is, this finishing portion is made large and extra large in advance, and finishing is performed to a specified dimension F. A screw hole 97a for attaching a reflecting mirror is provided using a jig or the like using the square hole of the waveguide as a reference.

Since the rectangular tube 95 is joined to the flange 9, it serves to reinforce the flange base portion of the waveguide.

As described above, the present invention is not limited to the illustrated embodiment; the waveguide may be oriented not horizontally but also in an inclined or vertical direction, and the flange is not necessarily located on the central axis. It may also be an offset case.

The hanging portion may be continuous with the U-shaped portion, and the horn antenna portion may be configured such that only two opposing surfaces are inclined, and cutting the outer shape is not necessarily required. For example, it may be used as it is or may be chamfered.

Regarding the waveguide, it is preferable to curve the narrow side from the viewpoint of strength, but the wide side may also be used. Regarding the material,
Copper, brass, aluminum, and others can be implemented. The frequency band is preferably a millimeter wave band of 15 to 50 GHz, but may be higher than that, or may be a microwave band or lower.

The supporting mold need not receive the entire U-shaped part, but may be the main part, and the sub-mold may have the same area as the main mold. Although more screws may be tightened, it is also possible to install bolts and fasten with nuts.

Even faster, one-touch attachment and detachment can be achieved by fastening with a cam. It goes without saying that the button may not be pressed vertically, but may be pressed horizontally.

〔Effect of the invention〕

As described above, according to the method of the present invention, an integral horn antenna is attached to one end of the feeding waveguide, and a flange is reinforced and attached to the other end via the U-shaped part, resulting in good manufacturability, strength, and radio wave. has good conductivity,
Since the flange is not a square hole, it is also advantageous in terms of accuracy and cost.

[Brief explanation of drawings]

FIG. 1 shows a state side view of an intermediate process according to the present invention.
Figure 2 shows the side surface of the straight pipe formed into a curve, Figure 3 shows the horn antenna molding support mold in a separated state, Figure 4 shows the horn antenna shape molding mold, Figure 5 shows the horn antenna immediately after molding, and Figure 6 7 is a side cross section showing the externally processed part, FIG. 7 is the E-E cross section of FIG. A side view of a partial cross section of the entire antenna, FIG. 10 shows a main part showing conventional flange attachment, and FIG. 11 shows a main part showing manufacturing of a conventional horn antenna. In the figure, 1 is a reflecting mirror, 2 is a feed waveguide, 21, 3
1 and 9 are flanges, 61 is a horn antenna part, 6
4 is a flange attachment part, 7 is a support mold, 8 is a mold, 95
indicates a square tube.

Claims (1)

[Claims] 1. A rectangular waveguide is bent into a U shape using a bending mold with a predetermined bending radius between the horn antenna forming side end where the horn antenna is formed and the flange side end where the flange is attached. process and
inserting and supporting the curved rectangular waveguide into a receiving support mold having a concave groove that coincides with the curved portion and a horn antenna forming side end that is continuous with the concave groove and is expanded into a predetermined tapered shape; , a horn antenna forming part having a tapered part that is wider than the inner shape of the waveguide in the axial direction is inserted into the open end of the horn forming side of the rectangular waveguide, and the waveguide is inserted into the tapered expanded part of the receiving support type. Steps of integrally forming the horn antenna part by press-fitting the horn antenna until they are in close contact with each other and expanding them at an angle, and attaching the flange to a predetermined position on the flange side end of the rectangular waveguide with reference to the open end where the horn antenna is formed. 1. A manufacturing method for integrally forming a feed conductor waveguide and a horn antenna.