JPH0522019A - Four-wire back fire helical antenna - Google Patents

Abstract

PURPOSE:To reduce man-hour for work by connecting the first terminal part connecting part of a first radiating member to a coaxial central conductor, a second terminal part connecting part to a coaxial outer conductor and the first and second terminal part connecting parts of a second radiating member to the coaxial outer conductor. CONSTITUTION:Radial conductors 5 and 7, arm 13 and rear connector 49 are integrally formed at a first radiating member 14. Second radiating members 9 and 11, arm 27 and rear connector 50 are integrally formed. In the state of facing the first and second bent radiating members 14 and 16 each other, a through hole is inserted to a coaxial cable 38 and soldered to the soldering part of the coaxial outer conductor, the arm 13 is soldered to the soldering part of a coaxial central conductor 39 and the arm 27 is soldered to the soldering part of a coaxial outer conductor 43. Therefore, the number of parts can be decreased, and connecting parts in the case of assembly can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backfire helical antenna used in a navigation system such as GPS.

[0002]

2. Description of the Related Art In recent years, along with the development of information society, mobile communication and satellite communication have become popular, and a navigation system such as GPS for receiving the radio waves of an artificial satellite to detect the position and speed of a mobile has been put into practical use. ing. With GPS,
A radio wave having a frequency in the L band is used, and a backfire helical antenna, a spiral antenna, or the like has been put into practical use as a receiving antenna.

FIG. 4 is a perspective view of a conventional backfire helical antenna. A flexible substrate film 3 is wound around the outer circumference of the bobbin 1 which is a cylinder and has a cylindrical shape. The bobbin 1 has a role of holding the flexible substrate film 3 in a cylindrical shape. On the surface of the flexible substrate film 3, four spiral radiation conductors 5,
7, 9, 11 are formed by etching.

A coaxial cable 38 is arranged at the position of the center axis of the cylinder of the bobbin 1. The coaxial cable 38 is
The coaxial center conductor 39, the insulator 41 provided around the coaxial center conductor 39, and the coaxial outer conductor 43 provided around the insulator 41 are provided.

The arm 13 is soldered to the first end of the coaxial center conductor 39 with solder 45. Arm 1
The first end 23 of the radiating conductor 5 is soldered to the first end 15 of No. 3 with the solder 19. Second arm 13
The first end 25 of the radiation conductor 7 is soldered to the end 17 with solder (not shown).

The arm 2 is attached to the first end of the coaxial outer conductor 43.
7 is soldered with solder 47. Arm 27
The first end portion 35 of the radiation conductor 9 is soldered to the first end portion 29 by the solder 33. The first end 37 of the radiation conductor 11 is soldered to the second end 31 of the arm 27 with solder (not shown).

A rear connecting piece 49 is soldered to the coaxial outer conductor 43 by soldering. First of the rear connecting piece 49
The connecting portion 51, the second connecting portion 53, the third connecting portion 55, and the fourth connecting portion 57 respectively include the second end portion 5 of the radiation conductor 11.
9, the second end 61 of the radiation conductor 7, the second end 63 of the radiation conductor 5, and the second end 65 of the radiation conductor 9 are soldered. 67 and 69 are solders. Radiation conductors 5, 7, 9, 1
1 is formed so as to wind around the bobbin 1 of 1/4 to 1/2 circumference.

The operation of the helical antenna shown in FIG. 4 will be described below. The total length of the first loop constituted by the radiation conductors 5, 11, the arms 13, 27 and the rear connection piece 49 is set to be slightly longer than the wavelength used, and the radiation conductors 7, 9, the arms 13, 27 and the rear connection are also set. The total length of the second loop formed by the piece 49 is set to be slightly shorter than the wavelength used, and at the used wavelength, the longer first loop exhibits capacitive impedance and the shorter second loop. The loop exhibits an inductive impedance.

Therefore, by providing an appropriate difference in the total length of both loops, the radiation conductors 5, 7, which are adjacent to each other, even though both loops are fed in parallel.
It is possible to cause a 90-degree phase difference between the currents flowing in 9 and 11, and circularly polarized waves are efficiently radiated.

[0010]

However, in the conventional 4-wire backfire helical antenna, the radiation conductors 5, 7, 9, 11 and the arms 13, 27 and the rear connecting piece 49 are used.
Since it was an independent part, there was a problem that there were many soldering points during assembly and the number of man-hours was large.

The present invention has been made to solve the above-mentioned conventional problems. An object of the present invention is to provide a 4-wire backfire helical antenna having a structure capable of reducing the number of working steps.

[0012]

A four-wire backfire helical antenna according to the present invention comprises a first radiation conductor,
A second radiating conductor arranged side by side with the first radiating conductor, and a first end connecting part connecting the first end of the first radiating conductor and the first end of the second radiating conductor, Second of the first radiation conductor
First and second radiating members integrally formed with a second end connecting portion that connects the end and the second end of the second radiating conductor;
A coaxial line having a coaxial center conductor, an insulator formed around the coaxial center conductor, and an outer coaxial conductor formed around the insulator is provided.

The first and second radiating members are each bent into a spiral shape. The first end connecting portion of the first radiating member is connected to the coaxial center conductor, and the second end connecting portion of the first radiating member is connected to the coaxial outer conductor. The first and second end connecting portions of the second radiating member are connected to the coaxial outer conductor.

[0014]

The first and second radiation members have a structure in which the first radiation conductor, the second radiation conductor, the first end connecting portion and the second connecting portion are integrally formed. Therefore, the connection points during assembly are
A coaxial center conductor with the first end connecting portion of the first radiating member, a coaxial outer conductor with the second end connecting portion of the first radiating member, and a coaxial outer conductor with the first and second end connecting portions of the second radiating member. In 4 places. That is, since the conventional independent parts are integrally formed, the number of parts can be reduced and the number of connection points at the time of assembly can be reduced.

[0015]

1 is a perspective view of an embodiment of a four-wire backfire helical antenna according to the present invention. First
The radiation member 14 has a structure in which the radiation conductors 5 and 7, the arm 13, and the rear connection piece 49 are integrally formed. The second radiating member 16 includes the radiating members 9 and 11, the arm 27, and the rear connecting piece 50.
Has an integrally formed structure. The first and second radiating members 14 and 16 are conductor plates having a proper rigidity such as cold rolled iron plates, aluminum plates and brass plates having a thickness of about 0.5 to 2 mm.

The second radiating member 16 is formed by punching a sheet metal press into the shape shown in FIG. 2, and the radiating members 9 and 1 are formed by bending the two-dot broken lines A to D by about 90 degrees.
1, each part of the arm 27 and the rear connecting piece 50 is formed.
The two arms of the arm 27 have different lengths. A ~
D does not necessarily have to be bent at a right angle, and may be bent so that the corner is rounded. Reference numeral 44 denotes a through hole, and the coaxial cable 38 is inserted into the through hole 44. First radiating member 1
4 is formed in the same manner as the second radiating member 16.

Bent first and second radiating members 1
As shown in FIG. 3, the through holes 44 and 48 are inserted into the coaxial cable 38 in a state in which they are opposed to each other, and the through holes 44 and 48 are soldered to the coaxial outer conductor 48 as shown in FIG.
0, the arm 13 is soldered to the soldering portion 56 of the coaxial center conductor 39, and the arm 27 is soldered to the coaxial outer conductor 43.
It is soldered to the soldering portion 58 of. This state is shown in FIG. 45, 47 and 54 are solder.

[0018]

Since the four-wire backfire helical antenna according to the present invention has a reduced number of parts,
The number of connection points during assembly can be reduced, and therefore, the number of work steps can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a four-wire backfire helical antenna according to the present invention.

FIG. 2 is a plan view of a second radiating member 16 used in an embodiment of a four-wire backfire helical antenna according to the present invention.

FIG. 3 is a perspective view for explaining the assembly of an embodiment of a four-wire backfire helical antenna according to the present invention.

FIG. 4 is a perspective view of a conventional 4-wire backfire helical antenna.

[Explanation of symbols]

 5, 7, 9, 11 Radiating conductor 13, 27 Arm 49, 50 Rear connecting piece 14 First radiating member 16 Second radiating member 38 Coaxial cable 39 Coaxial center conductor 41 Insulator 43 Coaxial outer conductor

Claims (1)

Claim: What is claimed is: 1. A first radiating conductor, a second radiating conductor which is arranged side by side with the first radiating conductor interposed therebetween, a first end of the first radiating conductor, and the first radiating conductor. 2 1st end connection part which connects the 1st end part of a radiation conductor, and 2nd end connection which connects the 2nd end part of the said 1st radiation conductor, and the 2nd end part of the said 2nd radiation conductor First and second radiating members integrally formed with a portion, a coaxial center conductor, an insulator formed around the coaxial center conductor, and a coaxial outer conductor formed around the insulator, And a coaxial line having, wherein the first and second radiating members are respectively bent into a spiral shape, and a first end connecting portion of the first radiating member is connected to the coaxial center conductor, A second end connecting portion of the radiating member is connected to the coaxial outer conductor, and first and second end connecting portions of the second radiating member. Connected to said coaxial outer conductor, 4-wire backfire helical antenna.