JP4105408B2 - Sleeve antenna - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sleeve antenna in which a sleeve element is provided around a coaxial feed line, and more particularly to a sleeve antenna having a structure suitable for a coaxial feed line having a small diameter.
[0002]
[Prior art]
FIG. 6 shows a schematic diagram of a sleeve antenna. As shown in the figure, the sleeve antenna has a rod-like element 22 in which a central conductor portion is erected by removing an outer conductor of a portion having a length of about a quarter wavelength of the tip end portion of the coaxial feeder 21, and a base portion of the rod-like element 22. It is composed of a cylindrical sleeve element 23 which is connected to an external conductor and covers the coaxial feeder 21 so as to hang downward by a length of about a quarter wavelength.
In the conventional sleeve element, as shown in the longitudinal sectional view of FIG. 7, only a rod-shaped conductor insertion hole is formed so as to close the upper end of the sleeve 23 and is electrically connected to the outer conductor 24 of the coaxial feeder 21 by soldering. Was.
[0003]
[Problems to be solved by the invention]
However, in the case of the connection form by soldering, if the cable used as the coaxial feeder 21 is, for example, a thin 1.5D, the insulating portion of the cable deteriorates due to heat generated during soldering when the sleeve is connected. Had a problem. Further, the mechanical strength of the connecting portion is weak and there is a problem in reliability, and the sleeve element is expensive because it cannot be easily manufactured even if the coaxial feeding line becomes thin.
The present invention has been made in view of the above problems, even thinner is coaxial feed line connects the sleeve element without deteriorating the insulating portion to the outer conductor, also have sufficient mechanical strength, further inexpensively manufactured It is an object of the present invention to provide a sleeve antenna having a sleeve element that can be used.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is a rod-like element formed by removing the outer conductor at the tip of the coaxial feed line, and is electrically connected to the outer conductor at the base of the rod-like element to surround the coaxial feed line. In the sleeve antenna having the sleeve element arranged so as to cover the electrical connection, the electrical connection between the sleeve element and the coaxial feed line is inserted between the dielectric around the central conductor of the coaxial feed line and the outer conductor outside the conductor. The sleeve element is formed through a connecting member having an insertion cylinder, and the sleeve element is at least one set of conductive plates arranged in parallel around the coaxial power supply line with the coaxial power supply line as the axis of symmetry. A stopper that engages with the connecting member is used to connect the connecting member and the sleeve element, and a mounting portion of the sleeve element is placed on the connecting member, and the sleeve element is connected by the stopper. Wherein the fixing on the wood.
[0006]
The invention of claim 2 is characterized in that, in the invention of claim 1 , the sleeve elements are composed of two sets of conductive plate members arranged orthogonally.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a sleeve antenna according to the present invention, where 1 is a coaxial feed line, 2 is a rod-shaped element, 3 is a sleeve element, and the coaxial feed line 1 and the rod-shaped element 2 are arranged in a straight line.
The rod-shaped element 2 is formed of a central conductor excluding the outer conductor of the coaxial feeder 1 and a dielectric covering the periphery thereof, and has a length of approximately a quarter wavelength of the operating frequency. The sleeve element 3 is composed of two sets of conductive plates 3a and 3b in which the feeder line 1 is arranged opposite to the target axis in parallel to the coaxial feeder line 1, and both are arranged orthogonally to each other in a cross shape at the top. It is connected. The conductive plates 3a and 3b are formed with a length of about a quarter wavelength of the operating frequency, and the connecting portion 6 is formed with a circular insertion hole 7 at the center, and a metal connecting member 9 is mounted and supplied. The outer conductor of the electric wire 1 is connected.
[0008]
FIG. 2 is an exploded view excluding the power supply line of FIG. 1, showing the sleeve element 3 and its mounting member, and FIG. 3 shows a cross section of a connection portion where the sleeve element 3 is connected to the coaxial power supply line 1. As shown in the figure, the connecting member 9 has a disk-like base 9a on which the connecting portion 6 of the sleeve element 3 is placed, and a substantially cylindrical protrusion 9b is formed at the center thereof, and the protrusion 9b is a stopper. A groove 12 for mounting the E-ring 11 is formed. An insertion hole 14 through which the rod-shaped element 2 is inserted is formed at the center, and an insertion cylinder 13 is formed on the lower surface of the connecting member 9 to insert the rod-shaped element 2 and insert it into the end of the feeder line.
Reference numeral 4 denotes a sleeve holding member, which is formed by resin molding, has a feeding wire insertion hole 4a at the center, and has sleeve holding grooves 4b on the four sides to hold the lower release end of the sleeve element 3. However, the sleeve holding member 4 may be omitted if the sleeve can be sufficiently held only by the connecting member, such as when a radome is used. Reference numeral 10 denotes a ferrule for preventing the connecting member 9 from coming off.
[0009]
Next, a procedure for mounting the sleeve element 3 will be described with reference to FIG. First, the sleeve holding member 4 and the ferrule 10 are inserted through the feeder 1. Then, the rod-like element 2 composed of the central conductor 2a of the feeder line 1 and the surrounding dielectric 17 is inserted into the insertion hole 14 of the connecting member 9, and the connecting member 9 is inserted into the end portion of the feeder line serving as the end portion of the external conductor 16. And put it on. At this time, the insertion tube 13 is inserted between the outer conductor 16 and the dielectric 17. After the insertion, the ferrule 10 is placed on the insertion protrusion 13 and fixed by caulking.
After attaching the connecting member 9 in this way, the sleeve element 3 is mounted. The sleeve element 3 is mounted by inserting the rod-shaped element 2 through the insertion hole 7, placing the connecting portion 6 of the sleeve element 3 on the base 9 a of the connecting member 9, and mounting the E ring 11 in the groove 12 on the upper part. The upper portion of the sleeve element 3 may be electrically connected, and the sleeve holding member 4 previously passed through the power supply line 1 may be attached to the lower portion. The insertion hole 14 has a diameter that allows the center conductor 2a covered with the dielectric 17 of the coaxial feeder 1 to be inserted.
In this way, the sleeve element 3 is mounted via the connecting member and is electrically connected to the external conductor.
[0010]
In this way, since soldering or welding is not used to connect the sleeve element and the feeder external conductor using the connecting member, the insulating portion does not deteriorate even if a thin coaxial feeder is used. In addition, since the connecting member is inserted between the outer conductor and the inner dielectric, the connection between the sleeve and the outer conductor can be ensured, and the connection portion can have sufficient strength.
Further, the sleeve element does not have to be cylindrical, and by arranging two pairs of conductive plate members around the power supply line as described above, it is possible to obtain radiation characteristics similar to the cylindrical shape. In this case, the sleeve element can be easily manufactured by cutting the conductive plate material into a cross shape and then bending it, and can be manufactured at low cost.
[0011]
FIG. 4 shows another embodiment of the present invention and shows a modification of the sleeve element. As shown in the figure, the sleeve element 18 may be composed of a pair of conductive plates 18a, 18a arranged opposite to the power supply line, and even if formed in this way, the radiation characteristics are not greatly deteriorated.
[0012]
Although the above embodiment describes the state where the antenna is erected with the rod-shaped element facing upward, it may be arranged in the opposite direction depending on the state of the radio wave used or the installation location. It can also be installed towards the direction. The sleeve element is formed by punching a metal plate and bending it. However, a metal film may be formed on the surface of the resin molded product to form a sleeve element. Further, the stopper may not be an E-ring, and for example, a leaf spring as shown in FIG. 5 can be used. Further, a tap may be cut around the protrusion 9b without providing the groove 12, and a nut may be used as a stopper.
[0013]
【The invention's effect】
As described above in detail, according to the first aspect of the present invention, since the soldering and welding are not used for connection between the sleeve and the outer conductor of the feeder line, the insulating portion can be obtained even if a thin coaxial feeder is used. There is no deterioration. Further, since the connecting member is inserted and attached to the power supply line so as to be in contact with the outer conductor of the power supply line, the sleeve can be securely connected, and the connection portion can have sufficient strength.
[0014]
Even if the coaxial power supply line is thin, the sleeve element can be easily manufactured by cutting the conductive plate into a cross shape, for example, and then bending, and can be manufactured at low cost.
According to the invention of claim 2 , even if the sleeve is not cylindrical, it is possible to obtain radiation characteristics similar to the cylindrical shape.
[Brief description of the drawings]
FIG. 1 is a perspective view of a sleeve antenna showing an example of an embodiment of the present invention.
2 is a perspective view of the sleeve element of FIG. 1 and its fixture.
3 is a longitudinal sectional view of a main part of FIG.
FIG. 4 is a perspective view of a sleeve element as a main part of another embodiment of the present invention.
5A and 5B show another example of a stopper, wherein FIG. 5A is a perspective view and FIG. 5B is a side view.
FIG. 6 is a schematic view of a sleeve antenna.
FIG. 7 is a longitudinal sectional view of a conventional sleeve antenna.
[Explanation of symbols]
1 ... Coaxial feeder, 2 ... Rod element, 2a ... Central conductor, 3 ... Sleeve element, 3a, 3b ... Conductive plate, 6 ... Connection, 7 ... Insertion hole, 9 ... Connecting member, 10 ·· Ferrule, 11 ·· E-ring, 16 ·· Outer conductor, 17 ·· Dielectric, 18 ·· Sleeve element.

Claims (2)

In a sleeve antenna having a rod-like element formed by removing an outer conductor at the tip of a coaxial feed line, and a sleeve element arranged so as to cover the periphery of the coaxial feed line by being electrically connected to the outer conductor at the rod-like element base ,
While making electrical connection between the sleeve element and the coaxial feed line through a connecting member having an insertion cylinder inserted between the dielectric around the central conductor of the coaxial feed line and the outer conductor outside thereof,
The sleeve element is at least one set of conductive plates arranged in parallel and opposite to each other around the coaxial power supply line with the coaxial power supply line as the axis of symmetry,
Further, a stopper that engages with the connecting member is used for connecting the connecting member and the sleeve element, and a mounting portion of the sleeve element is placed on the connecting member, and the sleeve element is connected by the stopper. A sleeve antenna fixed on a member . Sleeve antenna of claim 1 wherein comprising two pairs of conductive plate body sleeve elements are arranged orthogonally.

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