JP2003123555A - Extra fine leakage coaxial cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extra fine leakage coaxial cable with superior leakage characteristic, flexibility, terminal workability, bending characteristic, manufacturing cost and component integration degree. SOLUTION: In the coaxial cable, an inner conductor 5 is thinner than 36 AWG, an outer conductor 7 is composed of a metal wire, and a gap 30 is formed in the outer conductor 7. It can be easily installed in a narrow and intricate place to radiate an electric wave.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extremely thin leaky coaxial line used for electromagnetic wave radiation, and more particularly to a leak characteristic, flexibility,
The present invention relates to an ultrafine leaky coaxial wire excellent in terminal processability, bending property, manufacturing cost, and component integration degree.

[0002]

2. Description of the Related Art With the miniaturization of electronic equipment, IC testers, and medical equipment, the diameter of equipment electric wires applied to these equipment is also becoming smaller. In addition, with higher performance of devices (for example, higher definition of images and higher communication speed), higher transmission quality is required for transmission between devices and inside devices. Especially for electric wires for medical equipment, internal wiring of personal computers, servers, etc.
It is required to meet the MI noise requirement.

As an electric wire excellent in shielding, a coaxial wire is known in which an outer conductor is provided on the outside of an inner conductor serving as a transmission line via an insulator. The following are the mainstream structures of the outer conductor of the coaxial line that are currently in practical use.

Structure in which a metal wire (element wire) of 0.02 mm to 0.05 mm is spirally wound around an insulator (horizontal winding shield structure) A structure in which a plastic tape provided with a metal vapor deposition film is wound around the above (Horizontal winding shield + vapor-deposited tape structure) Structure in which element wires of 0.05 mm or less are braided (braided shield structure) These coaxial wires surround the shield layer in order to prevent intrusion of external noise and radiation of electromagnetic waves from the inside. It is necessary to make it uniform and smooth in the direction. That is, the conventional outer conductor of the coaxial line covers the insulator evenly.

On the other hand, a leaky coaxial line is known, which has a concept opposite to that of shielding and forms a gap in an outer conductor to positively leak a signal from the inside. The leaky coaxial line is used for transmission of AM waves and FM waves of radio broadcasting in a tunnel. The conventional outer conductor of a leaky coaxial line is a metal tube formed by rolling a metal tape in the width direction and welding both ends, and a slit is formed in the metal tube. Since the conventional leaky coaxial line needs to transmit radio waves over a long distance, the size of the inner conductor is large, and thus the outer diameter is considerably large. Such a leaky coaxial line is inconvenient for handling in a narrow space. In addition, the conventional leaky coaxial line is laid in a relatively long space and has a low flexibility (easiness of bending) for a long-term stationary use, and is weak against repeated bending (flexing). The characteristics are inferior).

[0006]

By the way, many of the micromachines expected to be used in the medical and industrial fields in the future use electromagnetic waves to supply energy to a power source and control their operations. In such a micromachine, when operating in a very narrow place such as inside the machine or inside the human body, a good radio wave environment is an essential condition for operation, and an environment with poor radio wave conditions or electromagnetic waves in complicated metal pipes etc. It cannot be expected to operate in an environment surrounded by other shields.

Since the above-mentioned leaky coaxial line cannot be handled in a narrow space, it cannot be used for electromagnetic wave transmission to a micromachine.

The applicant of the present invention has reversed the concept of the coaxial line used for the purpose of shielding electronic / medical devices described above and is suitable for use in a narrow and complicated place such as electromagnetic wave transmission to a micromachine. It is intended to realize a leaky coaxial line.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and to provide an ultrafine leaky coaxial line excellent in leakage characteristics, flexibility, terminal processability, bending characteristics, manufacturing cost and component integration. .

[0010]

In order to achieve the above object, the present invention is characterized in that the inner conductor is a coaxial wire thinner than 36 AWG, the outer conductor is made of a metal wire, and a gap is formed in the outer conductor. There is something.

The metal wire may be a copper or copper alloy wire having a diameter of 0.1 mm or less and an electric conductivity of 70% IACS or more.

The metal wire may be tin-plated or silver-plated with an elongation of 1% or more.

An insulator may be arranged in the gap.

A second outer conductor may be provided outside the outer conductor, and a gap may be formed in the second outer conductor.

A plurality of the ultra-fine leaky coaxial lines may be arranged in parallel, and all the external conductors may be soldered together.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

The ultrafine leaky coaxial line shown in FIG. 1 comprises an inner conductor (also referred to as a center conductor) 5, an insulator 6, an outer conductor 7, and a jacket 8. The inner conductor 5 is a 40 AWG (outer diameter of about 0.09 mm) inner conductor obtained by silver-plating a stranded wire formed by twisting seven copper alloy wires having a diameter of 0.03 mm.
The insulator 6 is made of fluororesin. The outer conductor 7 is formed by horizontally winding or braiding a tin-plated copper element wire having a diameter of 0.03 mm. A gap 30 having an opening width of about 0.2 mm is formed in a part of the outer conductor 7 in the circumferential direction.
The gap 30 shown in the perspective view is formed in a spiral shape in parallel with the wire wound in a spiral shape.

The ultrafine leaky coaxial line shown in FIG. 2 has an inner conductor 9, an insulator 10, a first outer conductor 11, and a second outer conductor 1.
2, consists of a jacket 13. The inner conductor 9 has a diameter of 0.0
It is a 40 AWG inner conductor obtained by silver-plating a twisted wire formed by twisting seven 3 mm copper alloy wires. Insulator 10
Is made of fluororesin. The first outer conductor 11 has a diameter of 0.
It is made by winding or braiding a 03 mm tin-plated copper element wire. A gap 31 having an opening width of about 0.2 mm is formed in a part of the first outer conductor 11 in the circumferential direction. As the second outer conductor 12, a tape obtained by vapor-depositing a copper tape having a thickness of 0.1 μm on a polyester tape having a thickness of 0.04 mm on the first outer conductor 11 was wound in a spiral shape in a reverse winding to the first outer conductor 11. It is a thing. This second outer conductor 12
Also, a gap 32 is formed. The gaps 31 and 32 shown in the perspective view are formed in a spiral shape in parallel with the wire or tape wound in a spiral shape.

The first outer conductor 11 and the second outer conductor 12 are different in conductor type (tin-plated copper and copper), shape (element wire and vapor deposition tape), and winding method (forward / reverse). Also, the gap 3
The spiral of No. 2 is a spiral wound in the opposite direction to the gap 31.

The extra-fine leaky coaxial line shown in FIG. 3 has an inner conductor 14, an insulator 15, a first outer conductor 16, and a second outer conductor 1.
It consists of 7 and jacket 18. The inner conductor 14 has a diameter of 0.
It is a 40 AWG inner conductor obtained by silver-plating a stranded wire in which seven 03 mm copper alloy wires are stranded. Insulator 15
Is made of fluororesin. The first outer conductor 16 has a diameter of 0.
It is made by winding or braiding a 03 mm tin-plated copper element wire. A gap 33 having an opening width of about 0.2 mm is formed in a part of the first outer conductor 16 in the circumferential direction. The second outer conductor 17 is obtained by horizontally winding or braiding a tin-plated copper element wire having a diameter of 0.03 mm on the first outer conductor 16 in the reverse winding of the first outer conductor 16. The second outer conductor 16 also has a gap 34 with an opening width of about 0.2 mm.
Are formed. Gap 33, 34 shown in perspective view
Are formed in a spiral shape in parallel with the wire wound in a spiral shape.

The first outer conductor 16 and the second outer conductor 17 have the same conductor type (tin-plated copper) and shape (strand), but different winding methods (forward and reverse). Also, the gap 33
And the opening width of the gap 34 are the same. The spiral of the gap 34 is a spiral wound in the opposite direction to the spiral of the gap 33.

The extra-fine leaky coaxial lines shown in FIGS.
It has the following advantages.

The inner conductor is 36 AWG (outer diameter of about 0.15 m
Since it is thinner than m), the outer diameter of the ultra-fine leaky coaxial line can be reduced. Further, since the outer conductor is made of a metal wire, it is possible to give flexibility. Further, since the gap is formed in the outer conductor, the signal propagating in the inner conductor can be radiated to the outside as an electromagnetic wave. That is, it is possible to have leakage characteristics. As a result, it can be easily installed in a narrow and complicated place, and can be suitably used for electromagnetic wave transmission to a micromachine (above, according to claim 1).

Further, since the metal wire diameter of the outer conductor is 0.1 mm or less, the extra fine leaky coaxial wire can have sufficient flexibility. When the conductivity (electrical conductivity) of the metal wire is low, the transmission characteristics of the ultra-fine leaky coaxial wire deteriorates and the signal attenuation increases, but the conductivity of the metal wire is 70% IACS (conductivity of universal standard annealed copper IACS). Is 100% or more), a desired transmission characteristic can be maintained. Copper or a copper alloy satisfies this condition and is suitable for a metal wire. (The above is according to claim 2).

If the elongation of the metal wire (ratio of elongation to predetermined tension) is 1% or more, sufficient bending property and end workability can be secured. When tin plating or silver plating is applied to the metal wire, the batch connectability (the batch connection described later is easy) is good and the availability is easy (because it is a popular material, it can be easily obtained), so the ultrafine leaky coaxial line is inexpensive. Can be manufactured (as described above, according to claim 3). The plating may be solder plating.

Although not shown in the embodiment, mechanical strength can be secured by filling the gap with an insulator (according to claim 4).

Further, by providing the second outer conductor outside the first outer conductor, it becomes easy to adjust the leakage characteristic and the damping characteristic to desired characteristics (according to claim 5).

In addition to the embodiments shown in FIGS. 1 to 3, there are various embodiments as described below.

Two inner conductors may be arranged in parallel, and the two inner conductors may be housed in a common outer conductor to form a two-core parallel leaky coaxial.

The insulator may be made of a fluororesin or polyethylene foam.

The outer conductor may be a rectangular wire.

Two or more gaps may be formed in the circumferential direction of the outer conductor.

The ultrafine leaky coaxial line shown in FIG. 4 is integrated by arranging a plurality of ultrafine leaky coaxial lines each including an inner conductor 22, an insulator 21, an outer conductor 20, and a jacket 19 in parallel, as in FIG. It is a very fine leaky coaxial line. All of the outer conductors 20 are collectively solder-connected to this ultrafine leaky coaxial line. Therefore, the external conductor 20 can be easily joined to the ground connection pattern 24 on the connection board 23 when it is attached to the connection board 23 as shown in the drawing.
The internal conductors 22 are individually connected to the signal line connection pattern 25.

In this way, since a plurality of ultra-fine leaky coaxial lines are arranged in parallel and all the external conductors are collectively soldered in advance in advance, terminal processability (easy connection to the substrate = connection) (Workability) is improved, and the time required for the connection work is shortened compared to connecting the individual ultra-fine leaky coaxial lines one by one, so that the connection cost is reduced. In addition, since the plurality of ultra-fine leaky coaxial lines are closely attached to each other, it is possible to achieve integration and space saving as compared with wiring of the individual ultra-fine leaky coaxial lines (according to claim 6).

Next, the results of actually investigating the various characteristics of the ultrafine leaky coaxial lines shown in FIGS. 1 to 3 will be described. In Table 1,
The sample number, leakage characteristics, flexibility, connection workability, bending characteristics, and manufacturing cost ratio are shown. The sample number 1 corresponds to the ultra-fine leaky coaxial line in FIG. 1, the sample number 2 corresponds to the extra-fine leaky coaxial line in FIG. 2, and the sample number 3 corresponds to the extra-fine leaky coaxial line in FIG. Regarding leakage characteristics, flexibility, and connection workability, the double circle is excellent, the circle is excellent, and the triangle is slightly good.
The bending property is a 90 ° bending property on the left and right, and a load of 0.49.
The number of repetitions until breakage is shown when N is applied and bending is repeatedly performed at 90 ° left and right with a bending radius of 5 mm. The manufacturing cost ratio is shown as a value with sample number 1 being 100.

[0036]

[Table 1]

As shown in Table 1, leakage characteristics, flexibility,
The connection workability has been achieved at a practical level.

[0038]

The present invention exhibits the following excellent effects.

(1) It is possible to provide various characteristics such as leakage characteristics, flexibility, terminal processability, bending characteristics, manufacturing cost, and component integration degree at a very high level in a well-balanced manner.

[Brief description of drawings]

FIG. 1 is a cross-sectional view perpendicular to the axis of an ultrafine leaky coaxial line showing one embodiment of the present invention and a perspective view in a step-peeled state.

FIG. 2 is a cross-sectional view perpendicular to the axis of an ultrafine leaky coaxial line showing one embodiment of the present invention and a perspective view in a step-peeled state.

FIG. 3 is a cross-sectional view perpendicular to the axis of the ultra-fine leaky coaxial line showing one embodiment of the present invention and a perspective view in a step-peeled state.

FIG. 4 is a perspective view of an extra-fine leaky coaxial line in a stripped state showing an embodiment of the present invention.

FIG. 5 is a sectional view perpendicular to the axis of a conventional coaxial line.

[Explanation of symbols]

5, 9, 14 inner conductor 6, 10, 15 insulator 7, 11, 16 outer conductor (first outer conductor) 8, 13, 18 jacket 12, 17 Second outer conductor 30, 31, 32, 33, 34 Gap

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirohiro Tanaka             1-6-1, Otemachi, Chiyoda-ku, Tokyo             Standing Wire Co., Ltd.

Claims (6)

[Claims] 1. An ultrafine leaky coaxial line characterized in that the inner conductor is a coaxial line thinner than 36 AWG, the outer conductor is made of a metal line, and a gap is formed in the outer conductor. 2. The ultrafine leaky coaxial wire according to claim 1, wherein the metal wire is a copper or copper alloy wire having a diameter of 0.1 mm or less and an electrical conductivity of 70% IACS or more. 3. The ultrafine leaky coaxial wire according to claim 1, wherein the metal wire has an elongation of 1% or more and is plated with tin or silver. 4. The ultrafine leaky coaxial line according to claim 1, wherein an insulator is arranged in the gap. 5. The extra fine leakage according to claim 1, wherein a second outer conductor is provided outside the outer conductor, and a gap is also formed in the second outer conductor. Coaxial line. 6. The ultrafine leaky coaxial line according to claim 1, wherein a plurality of the ultrafine leaky coaxial lines are arranged in parallel, and all the outer conductors are collectively solder-connected.