JP2008171778A - Coaxial cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coaxial cable which has a flexibility and a high shielding property as well and can reduce an attenuation amount and has a little variation amount. <P>SOLUTION: The coaxial cable 1 is provided with a core conductor 11, a dielectric layer 12, an outer conductor layer 13 and a jacket 15, and between the outer conductor layer 13 and the jacket 15, there is provided a wound strip layer 14 composed of an ALPET 14a winding the outer conductor layer 13 and the wound strip layer 14 is wound at 25 to 50 degrees against a longitudinal axis direction of the coaxial cable 1. As a result, the outer conductor layer 13 is wound by the wound strip layer 14 from an upper side and the outer conductor 13 is pushed tight by the wound strip layer 14 and the outer conductor layer 13 is bound tight to strengthen adhesion between the outer conductors 14a to improve a shielding property. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coaxial cable.

  Conventionally, in some coaxial cables, an outer conductor is wound around a dielectric layer at a certain angle with respect to the longitudinal axis direction of the coaxial cable in order to improve the shielding effect and reduce the attenuation. There is something turned. The applicant of the present invention uses, as an outer conductor, a coaxial cable (Patent Document 1) using a metal tape in which a metal such as aluminum or copper is vapor-deposited on an insulating tape or a laminate of these foils, and a plurality of outer conductors. A coaxial cable (Patent Document 2) using a conductive wire of a book is proposed.

  In the coaxial cable of Patent Document 1, a metal tape serving as an outer conductor is wound from above a dielectric layer, and this metal tape is wound at an angle of 0 to 25 degrees with respect to the longitudinal axis direction of the coaxial cable. Yes. And by winding a metal tape at an angle within a predetermined range, the coaxial cable of Patent Document 1 achieves a sufficient shielding effect and further reduces the attenuation.

  In the coaxial cable of Patent Document 2, a plurality of conductive strands serving as outer conductors are spirally wound from above a dielectric, and the plurality of conductive strands are arranged in the longitudinal direction of the coaxial cable. Is wound at an angle of 8 to 19 degrees. And the coaxial cable of patent document 2 is providing the coaxial cable excellent in electrical characteristics, such as a shield effect, by winding several electroconductive strands by the angle within a predetermined range.

JP 2000-057863 A JP 2003-092031 A

  In the coaxial cable described above, a sufficient shielding characteristic is obtained by winding a metal tape as an outer conductor or a plurality of conductive strands around a dielectric layer at a predetermined angle, thereby reducing attenuation. I am trying.

  On the other hand, from the electronic equipment industry, etc., where the performance of equipment is increasing, it is flexible and has a higher shielding characteristic, so that it is possible to reduce the attenuation, and the fluctuation in attenuation is small. There is a strong demand for the use of coaxial cables.

  The present invention has been made in view of the various problems as described above, and an object thereof is to have flexibility and higher shield characteristics, to reduce the attenuation, and to reduce the fluctuation thereof. To provide a coaxial cable.

  To achieve the above object, in the coaxial cable of the present invention, an inner conductor, a dielectric layer provided on the outer periphery of the inner conductor, an outer conductor layer provided on the outer periphery of the dielectric layer, and the outer conductor layer A coaxial cable provided with a protective coating layer provided on the outer periphery of the winding cable, and a winding band comprising a winding band for winding the outer conductive layer between the outer conductive layer and the protective coating layer A layer is provided, and the winding band layer is wound at a predetermined angle with respect to the longitudinal axis direction of the coaxial cable.

  Thereby, in the coaxial cable of the present invention, the winding band is further wound from above the outer conductor layer of the coaxial cable. Therefore, since the outer conductor layer is pressed by the winding band, the outer conductor layer is tightened, the degree of adhesion of the outer conductor layer is improved, and the shield characteristics are improved. In addition, since the outer conductor is tightened, it is difficult to form a gap in the outer conductor layer when the coaxial cable is bent, and it is possible to stably maintain a state in which the shield characteristics are improved.

  In the coaxial cable of the present invention, it is preferable that the winding band is a metallized tape. Thereby, since the winding band layer becomes a shield layer, two shields of the outer conductor layer and the winding band layer are provided, and the shield characteristics can be further improved. Moreover, in this coaxial cable, it is also possible to stably maintain a state in which the shield property is improved by closely contacting the winding band layer and the outer conductor layer.

  In the coaxial cable of the present invention, it is preferable that the predetermined angle is in a range of 25 degrees to 50 degrees. Thereby, in the coaxial cable of this invention, it becomes possible to clamp | tighten an outer conductor firmly with a wound belt layer, maintaining production efficiency, and it becomes possible to improve a shield characteristic.

  The coaxial cable of the present invention is characterized in that the outer conductor layer is wound in a single horizontal direction. The coaxial cable according to the present invention is characterized in that the outer conductor layer is wound twice horizontally. Thereby, in the coaxial cable of the present invention, even if the outer conductor layer is a single horizontal winding or a double horizontal winding, the outer conductor layer can be tightened by winding the winding band from above. Therefore, even if the number of turns of the outer conductor layer is increased, the present invention can be applied.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. The embodiments described below do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are not necessarily essential to the establishment of the present invention. Absent.

  First, the configuration of the coaxial cable 1 of the present embodiment will be described with reference to FIG. 1A is a perspective view of the coaxial cable 1 of the present embodiment, and FIG. 1B is a cross-sectional view of the coaxial cable 1 of the present embodiment. (C) is a figure which shows the process of winding the winding band of the coaxial cable 1. FIG.

  As shown in FIG. 1, the coaxial cable 1 of the present embodiment includes a center conductor 11 (inner conductor), a dielectric layer 12, an outer conductor layer 13, and a winding band layer that is a characteristic part of the present invention. 14 and a jacket 15 (protective coating layer). The coaxial cable 1 is formed by the following procedure.

  That is, in the coaxial cable 1, a plurality of conductors 11a are twisted to form a center conductor 11, and an outer periphery of the center conductor 11 is extruded and coated with a dielectric 12a using an extruder (not shown). The body layer 12 is formed. Then, the outer conductor layer 13 is formed by horizontally winding a plurality of conductor wires 13a on the outer periphery of the dielectric layer 12, and the outer periphery of the outer conductor layer 13 includes, for example, a horizontal winding direction of the conductor wires 13a and In the opposite direction, a metallized tape, for example, ALPET 14a (winding band) is spirally wound to form the winding band layer 14, which is a characteristic part of the present invention. The jacket 15 is formed by extrusion coating on the outer periphery of the wound belt layer 14. In this way, the coaxial cable 1 is formed.

  The coaxial cable 1 is made of, for example, a silver-plated annealed copper wire for the conductive wire 11a, a tetrafluoroethylene / hexafluoropropylene copolymer (hereinafter simply referred to as FEP), or a conductor wire 13a for the dielectric 12a. The material is tinned annealed copper wire, and the material of the jacket 15 is FEP.

  In addition, the material of the coaxial cable 1 of this embodiment is not limited to the material mentioned above, The thing of the other material normally used for a coaxial cable can also be used. For example, other fluororesins such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene-pearl fluoroalkyl vinyl ether copolymer (PFA) can be used as the dielectric. Further, in the coaxial cable 1 of the present embodiment, the winding direction of the winding strip layer 14 is such that the conductor strand 13a laterally wound as the outer conductor layer 13 is tightened if the conductor strand 13a is tightened. May be in the same direction.

  The ALPET 14a is formed by laminating aluminum foil and polyethylene terephthalate (hereinafter simply referred to as PET) via polyvinyl chloride (hereinafter simply referred to as PVC) to form a tape. The ALPET 14 a is wound from above the outer conductor layer 13 in such a manner that the aluminum foil is in contact with the outer conductor layer 13.

  In the coaxial cable 1 of the present embodiment described above, as shown in FIG. 1C, a conductor wire 13 a is laterally wound as the outer conductor layer 13, and the winding band layer 14 is formed from above the outer conductor layer 13. The ALPET 14a that forms the cable is spirally wound at a predetermined angle θ with respect to the longitudinal axis direction of the coaxial cable 1. Therefore, the outer conductor layer 13 is tightened by applying a desired stress by the winding band layer 14, and the degree of adhesion between the conductor wires 13a of the outer conductor layer 13 is improved. Furthermore, since the plurality of conductor strands 13a are tightened by the winding strip layer 14, the winding strip layer 14 maintains the state where the conductor strands 13a are in close contact with each other, Even if the coaxial cable 1 is bent, it is possible to prevent the conductor strands 13a from being separated from each other at the bent portion. And since this winding belt layer 14 is formed of ALPET14a, this winding belt layer 14 itself also acts as a shield.

  Thereby, in the coaxial cable 1 of the present embodiment, the outer conductor layer 13 and the winding band layer 14 are provided with two layers having a shielding effect, and further, the conductor strand 13a of the outer conductor layer 13 is provided. Since it is tightened by the wound belt layer 14, the degree of adhesion between the conductor strands 13a is improved and the adhesion state is maintained, and the shielding effect of the outer conductor layer 13 can be further enhanced.

  Next, since the test for specifying the range was carried out about the predetermined angle (theta) which winds the winding belt | band | zone layer 14 in the coaxial cable 1 of this embodiment, this test is demonstrated using FIGS. To do.

  In this test, the shield test for determining the range of the predetermined angle θ by determining the relationship between the predetermined angle θ and the characteristic of the shielding effect, and the relationship between the predetermined angle θ and the attenuation amount are determined. Two tests were performed, a winding test specifying a range of the predetermined angle θ. 2 and 3 show the test results of the shield test, FIG. 4 shows the test method of the winding test, and FIGS. 5 to 10 show the test results of the winding test. First, the shield test will be described in detail with reference to FIGS.

  FIG. 2 is a table showing test results of the shield test, and FIG. 3 is a diagram showing test results of the shield test. In this shield test, four coaxial cables 1 having a predetermined angle θ wound around the winding band layer 14 are adjusted to a length of 3 m to be test cables A to D. This test cable A It was performed by the method called the absorption clamp method which detects the quantity which the signal inserted in -D leaks outside the test cables A-D using an RF (Radio Frequency) network analyzer. The inserted signal was sequentially changed from 0 Hz to 1 GHz, and the change in the shielding effect during that time was measured. For comparison, a braided coaxial cable that has been conventionally used was also tested.

  In the configuration of the four test cables A to D used in this shield test, the central conductor 11 is formed by twisting seven silver-plated annealed copper wires having an outer diameter of 0.102 mm, and FEP is formed on the outer periphery of the central conductor 11. A dielectric layer 12 is formed so as to cover an outer diameter of 0.9 mm, and 29 tin-plated annealed copper wires having an outer diameter of 0.102 mm corresponding to the conductor wire 13 a are formed on the outer periphery of the dielectric layer 12. The outer conductor layer 13 is formed by laterally winding at an angle of 9.6 degrees with respect to the longitudinal axis direction, and an aluminum foil having a thickness of 10 μm and a PET having a thickness of 12 μm are formed on the outer periphery of the outer conductor layer 13. ALPET 14a laminated through a PVC having a thickness of 2 to 3 μm is spirally wound to form a wound band layer 14, and a jacket made of FEP having a thickness of 0.12 mm on the outer periphery of the wound band layer 14 15 is formed by extrusion coating Is intended, the outside diameter of the test cable A~D is a 1,37Mm.

  Also, the conventional braided coaxial cable has a configuration in which a central conductor is formed by twisting seven silver-plated annealed copper wires having an outer diameter of 0.102 mm, and an outer diameter of 0.88 mm is obtained by covering the outer periphery of the central conductor with FEP. A dielectric layer is formed so that an outer conductor layer is formed on the outer periphery of the dielectric layer with a braided structure having 16 strokes and 6 slots using a tin-plated annealed copper wire having an outer diameter of 0.05 mm. The outer periphery of the layer is formed by extrusion coating a jacket made of FEP having a thickness of 0.12 mm. The outer diameter of this conventional braided coaxial cable is 1,37 mm.

  The test cables A to D each change the angle θ at which the winding band layer 14 is wound, and the test cable A has the winding band layer 14 in the longitudinal axis direction of the coaxial cable 1. The test cable B has a winding band layer 14 of 25 degrees with respect to the longitudinal axis direction of the coaxial cable 1, and the test cable C has a winding band layer 14 of 25 degrees with respect to the longitudinal axis direction of the coaxial cable 1. The test cable D is formed by spirally winding the wound belt layer 14 at an angle of 40 degrees with respect to the longitudinal axis direction of the coaxial cable 1.

  As is apparent from FIGS. 2 and 3, the test cables A to D having the characteristic configuration of the coaxial cable 1 of the present embodiment have an overall shielding effect higher than that of the braided coaxial cable. . Further, when the test cables A to D are compared, the test cable A has a shield effect of −51.7 dB when the signal is 10 MHz, and a shield effect of −48.5 dB when the signal is 100 MHz. The shield effect when the signal is 10 MHz is -52.5 dB, the shield effect when the signal is 100 MHz is -49.8 dB, and the test cable C has a shield effect of -53.4 dB when the signal is 10 MHz. However, the test cable D has a shield effect of -55.1 dB when the signal is 10 MHz, and a shield effect of -51.1 dB when the signal is 100 MHz.

  Therefore, the coaxial cable 1 of the present embodiment has a higher shielding effect than the conventional coaxial cable, and a higher shielding effect is obtained when the angle θ for winding the winding band layer 14 is larger. I understand that. That is, from the result of the shield test, it can be said that the angle θ for winding the winding belt layer 14 is preferably 20 degrees or more. However, as the winding angle θ increases, the width of the ALPE 14a of the winding belt layer 14 decreases in inverse proportion to the angle θ, so the productivity of the coaxial cable 1 decreases. Therefore, the upper limit of the angle θ for winding the winding belt layer 14 is 50 degrees in consideration of productivity. Therefore, in the shield test, it can be said that the angle θ for winding the wound belt layer 14 is preferably 20 degrees or more and 50 degrees or less. Next, the winding test will be described in detail with reference to FIGS.

  FIG. 4 is a diagram for explaining a test method of the winding test. First, the test method of the winding test will be described with reference to FIG. In the winding test, a test cable is wound 12 times around a pipe 20 having an outer diameter of 10 mm with an interval of 10 mm, and two types of signals of 5 GHz and 6 GHz are inserted into the wound test cable to attenuate the signal. Is measured.

  In this winding test, there are two types of tests: a test using the same test cables A to D as the shield test described in FIGS. 2 and 3 and a test using test cables F to H different from the shield test. A winding test was performed. First, the result of the test using the same test cables A to D as the shield test will be described with reference to FIGS.

  FIG. 5 is a table showing the test results of the winding test, FIG. 6 is a diagram showing the relationship between the attenuation amount of the winding test and the winding angle θ of the winding belt layer 14, and FIG. 7 is the attenuation amount of the winding test. It is a figure which shows the relationship between the fluctuation value of this, and the angle (theta) wound by the wound belt layer. In this winding test, a braided type coaxial cable conventionally used for comparison was also tested.

  As can be seen from FIG. 5, the attenuation of the braided coaxial cable is 3.67 dB / m at 5 GHz and 4.03 dB / m at 6 GHz, whereas the characteristic configuration of the coaxial cable 1 of this embodiment is as follows. In the test cables A to D, the attenuation of the test cable A is 3.360 dB / m at 5 GHz, 3.692 dB / m at 6 GHz, and the attenuation of the test cable B is 3.305 dB at 5 GHz. The attenuation of the test cable C is 3.233 dB / m at 5 GHz, 3.554 dB / m at 6 GHz, and the attenuation of the test cable D is 5 GHz. Sometimes 3.192 dB / m and at 6 GHz 3.510 dB / m. Therefore, it can be seen that the test cables A to D having the characteristic configuration of the coaxial cable 1 of the present embodiment have an overall reduced amount of attenuation compared to the braided type coaxial cable.

  Further, as is apparent from FIGS. 5 to 7, in the test cables A to D, the test cable in which the wound belt layer 14 is spirally wound at 40 degrees with respect to the longitudinal axis direction of the coaxial cable. D has the smallest value of attenuation and fluctuation of attenuation, and the difference between the attenuation amounts of the test cable A and the test cable D is about 0.2 dB / m. Therefore, the amount of attenuation of the coaxial cable 1 of this embodiment is reduced as compared with the conventional coaxial cable, and when the angle θ for winding the winding band layer 14 is increased, the amount of attenuation can be further reduced. I understand.

  The difference between the attenuation amount of the test cable C and the attenuation amount of the test cable D is about 0.04 dB / m, which is a small difference, and the variation in attenuation amount is almost the same at 6 GHz. For this reason, the amount of attenuation is reduced when the angle θ of winding the wound belt layer 14 exceeds 30 degrees. I understand. Therefore, even if the angle θ for winding the wound belt layer 14 is 40 degrees or more, the value of attenuation does not change greatly, and it is considered that a good state can be maintained. As described in the result of the shield test, the upper limit of the angle θ for winding the wound belt layer 14 is 50 degrees in consideration of productivity.

  Moreover, in the coaxial cable 1 of this embodiment, as can be seen from FIGS. 5 to 7, the winding amount of the winding belt layer 14 is greatly improved as compared with the conventional one, and the fluctuation amount is small. The angle θ is about 25 degrees.

  As described above, from the result of the attenuation test, the lower limit of the angle θ for winding the wound belt layer 14 is 25 degrees, and the upper limit is 50 degrees. When the attenuation and productivity are taken into consideration, it can be said that the most preferable angle for winding the wound belt layer 14 is 30 degrees or more and 40 degrees or less where the change in the attenuation is almost flat. Next, a winding test using another test cable will be described in detail with reference to FIGS.

  FIG. 8 is a table showing test results of a winding test using different test cables F to H, and FIG. 9 is an attenuation amount of the winding test using different test cables F to H and the winding band layer 14. FIG. 10 is a diagram showing a relationship between the winding angle θ of FIG. 10 and FIG. 10 is a graph showing the relationship between the fluctuation value of the attenuation amount of the winding test using different test cables F to H and the winding angle θ of the winding band 14 It is a figure which shows a relationship.

  The three test cables F to H used in this winding test are formed by twisting seven silver-plated annealed copper wires having an outer diameter of 0.079 mm to form the center conductor 11, and FEP is formed on the outer periphery of the center conductor 11. A dielectric layer 12 is formed so as to have an outer diameter of 0.7 mm, and 91 tin-plated annealed copper wires having an outer diameter of 0.05 mm corresponding to the conductor wire 13a are formed on the outer periphery of the dielectric layer 12, and the coaxial cable An external conductor layer 13 is formed by wrapping twice laterally at an angle of 8.3 degrees with respect to the longitudinal axis direction, and an aluminum foil having a thickness of 10 μm and a PET having a thickness of 12 μm are formed around the outer conductor layer 13. Are wound in a spiral manner to form a wound belt layer 14, and the outer periphery of the wound belt layer 14 is formed from an FEP having a thickness of 0.12 m. The jacket 15 is formed by extrusion coating Is intended, the outside diameter of the test cable F~H is a 1,13Mm.

  The test cables F to H each change the angle θ at which the winding band layer 14 is wound, and the test cable F has a winding band layer 14 of 19 with respect to the longitudinal axis direction of the coaxial cable. The test cable G has a winding band layer 14 of 25 degrees with respect to the longitudinal axis direction of the coaxial cable, and the test cable H has a winding band layer 14 of 32 degrees with respect to the longitudinal axis direction of the coaxial cable. Each of them is spirally wound at an angle of. Moreover, the comparative test cable E used in this attenuation amount test is one in which the winding bands 14 are not provided in the test cables F to H.

  As apparent from FIG. 8, the attenuation of the comparative test cable E is 4.940 dB / m at 5 GHz and 5.58 dB / m at 6 GHz, whereas the characteristic configuration of the coaxial cable 1 of the present embodiment. In the test cables F to H, the attenuation amount of the test cable F is 4.21 dB / m at 5 GHz and 4.65 dB / m at 6 GHz, and the attenuation amount of the test cable G is 4.5 dB at 5 GHz. The attenuation of the test cable H is 4.05 dB / m at 5 GHz and 4.45 dB / m at 6 GHz at 11 dB / m and 6 GHz. Therefore, it can be seen that the test cables F to H having the characteristic configuration of the coaxial cable 1 of the present embodiment have an overall reduced attenuation compared to the comparative test cable E.

  Further, as is clear from FIGS. 8 to 10, in the test cables F to H, the test cable in which the wound belt layer 14 is spirally wound at 32 degrees with respect to the longitudinal axis direction of the coaxial cable. H has the smallest attenuation value and attenuation value variation, and the difference between the attenuation amounts of the test cable F and the test cable H is about 0.2 dB / m. Therefore, the coaxial cable 1 of the present embodiment has a reduced attenuation compared to the conventional coaxial cable, and even when the outer conductor layer 13 is double-side wound, the winding band layer 14 is wound. It can be seen that the amount of attenuation is further reduced when the angle θ to be increased is increased.

  Further, the difference between the attenuation amount of the test cable G and the attenuation amount of the test cable H is about 0.06 dB / m, and the difference is small, and the fluctuation of the attenuation amount is caused by the test cable G and the test cable H. There is almost no difference. From this fact, the attenuation is reduced because the angle θ of winding the wound belt layer 14 is between 25 and 32 degrees, in other words, about 30 degrees, and the change in the attenuation level is almost flat. It turns out that it reaches a certain level. Therefore, even if the angle θ for winding the winding strip layer 14 is 32 degrees or more, the value of attenuation does not change greatly, and it is considered that a good state can be maintained. As described in the result of the shield test, the upper limit of the angle θ for winding the wound belt layer 14 is 50 degrees in consideration of productivity.

  Further, in the coaxial cable 1 of the present embodiment, when the outer conductor layer is a double horizontal winding, as can be seen from FIGS. 8 to 10, the attenuation is greatly improved as compared with the conventional one, and the fluctuation amount thereof. The winding angle θ of the winding strip layer 14 that decreases becomes approximately 25 degrees.

  As described above, from the result of the attenuation test, the lower limit of the angle θ for winding the wound belt layer 14 is 25 degrees, and the upper limit is 50 degrees. When the attenuation and productivity are taken into consideration, it can be said that the most preferable angle for winding the wound belt layer 14 is 30 degrees or more and 40 degrees or less where the change in the attenuation is almost flat.

  As described above, from the three types of test results, the range of the predetermined angle θ for winding the wound belt layer 14 is 25 degrees from the required attenuation value and 50 degrees from the viewpoint of productivity. And as a preferable range, it can be said that 30 degrees or more and 40 degrees or less are the most preferable angles for winding the wound belt layer 14.

  As described above, the above-described coaxial cable 1 of the present embodiment has the outer conductor layer 13 formed by horizontal winding with the conductor wire 13a, so that it is highly flexible and has a higher shielding effect than the conventional coaxial cable. It can be seen that the attenuation is also reduced. And it turns out that the shield effect improves more and the amount of attenuation decreases by enlarging angle (theta) which winds the winding belt layer 14. FIG. This is because, when the angle θ for winding the winding strip layer 14 is increased, the force for tightening the external conductor layer 13 by the winding strip layer 14 is increased accordingly, and therefore the degree of adhesion between the conductor wires 13a of the external conductor layer 13 This is to improve the amount. If the adhesion degree between the conductor strands 13a is improved, it becomes difficult to form a gap between the conductor strands 13a. Therefore, it becomes possible to prevent a reduction in the shielding effect due to a gap between the conductor wires 13a, and the shielding effect is improved. Further, since the winding band layer 14 is formed of the ALPET 14a, the winding band layer 14 itself also acts as a shield.

  As a result, the coaxial cable 1 of the present embodiment includes two layers having the shielding effect of the outer conductor layer 13 and the winding band layer 14, and the conductor strand 13 a of the outer conductor layer 13 is further provided. Since it is tightened by the wound belt layer 14, the degree of adhesion between the conductor strands 13a is improved, and the adhesion state is maintained, and the shielding effect of the outer conductor layer 13 can be further enhanced. Attenuation can be reduced.

  In the present embodiment, the wound belt layer 14 is formed of ALPET 14a which is a metallized tape, but the wound belt layer of the present invention is not limited to this. For example, any material may be used as long as the outer conductor layer can be tightened.

  The coaxial cable of the present invention can be applied to any device. For example, the present invention can be applied to an electronic device such as a computer, a computer, and a mobile phone, and further can be applied to a control circuit of a machine that needs to be equipped with a control device such as an automobile or an airplane in a narrow portion.

It is a figure which shows the coaxial cable 1 in embodiment of this invention. FIG. 6 is a first diagram showing a result of a shield test of the coaxial cable 1. It is a 2nd figure which shows the result of the shield test of the coaxial cable. It is a figure which shows the test method of the winding test of the coaxial cable. It is a 1st figure which shows the result of the winding test of the coaxial cable. It is a 2nd figure which shows the result of the winding test of the coaxial cable. It is a 3rd figure which shows the result of the winding test of the coaxial cable. It is a 1st figure which shows the result of the winding test of the coaxial cable 1 in which the outer conductor layer is double horizontal winding. It is a 2nd figure which shows the result of the winding test of the coaxial cable 1 by which the outer conductor layer is double horizontal winding. It is a 3rd figure which shows the result of the winding test of the coaxial cable 1 in which the outer conductor layer is double laterally wound.

Explanation of symbols

1 Coaxial cable,
11 Center conductor (inner conductor),
11a conductor,
12 dielectric layers;
12a dielectric,
13 outer conductor layer,
13a Conductor wire,
14 winding belt layers,
14a ALPET (winding belt),
15 jacket (protective coating layer),
20 pipes,

Claims (5)

An inner conductor,
A dielectric layer provided on the outer periphery of the inner conductor;
An outer conductor layer provided on the outer periphery of the dielectric layer;
A coaxial cable provided with a protective coating layer provided on the outer periphery of the outer conductor layer,
Between the outer conductor layer and the protective coating layer, a winding band layer comprising a winding band for winding the outer conductor layer is provided,
The coaxial cable, wherein the wound belt layer is wound at a predetermined angle with respect to a longitudinal axis direction of the coaxial cable. The coaxial cable according to claim 1, wherein the winding band is a metallized tape. The coaxial cable according to claim 1 or 2, wherein the predetermined angle is in a range of 25 degrees to 50 degrees. The coaxial cable according to any one of claims 1 to 3, wherein the outer conductor layer is single-side-wrapped. The coaxial cable according to any one of claims 1 to 3, wherein the outer conductor layer is double-side wound.

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