WO2008087919A1 - Coaxial cable - Google Patents

Abstract

Provided is a coaxial cable (1) comprising a center conductor (11), a dielectric layer (12), an external conductor layer (13) and a jacket (15). A wound band layer (14) made of an ALPET (14a) for winding the external conductor layer (13) is interposed between the external conductor layer (13) and the jacket (15). The wound band layer (14) is wound at an angle of 25 to 50 degrees with respect to the longitudinal axis direction of the coaxial cable (1). As a result, the wound band layer (14) is wound on the external conductor layer (13) so that the external conductor layer (13) is held by the wound band layer (14). Therefore, the external conductor layer (13) is fastened so that the contact between the external conductor layers (13) is improved to improve shielding characteristics. As a result, the coaxial cable can have a flexibility and the high shielding characteristics, and can reduce an attenuation quantity and have small attenuation fluctuations.

Description

 Description Coaxial Cable Technical Field

 The present invention relates to a coaxial cable. Background art

 Conventionally, in some coaxial cables, the outer conductor is placed on the 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 a coaxial cable (see Japanese Patent Application Laid-Open No. 2000-057863) using, as an outer conductor, 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. As an external conductor, a coaxial cable using a plurality of conductive strands (see Japanese Patent Laid-Open No. 2003-092031) is proposed.

 In the coaxial cable disclosed in Japanese Patent Laid-Open No. 2000-057863, a metal tape serving as an outer conductor is wound from above a dielectric layer, and the metal tape is rotated at 0 to 25 degrees with respect to the longitudinal axis direction of the coaxial cable. Winding at an angle. Then, by winding a metal tape at an angle within a predetermined range, the coaxial cable disclosed in Japanese Patent Laid-Open No. 2000-057863 achieves a sufficient shielding effect and further reduces the attenuation.

In the coaxial cable disclosed in Japanese Patent Laid-Open No. 2003-092031, a plurality of conductive strands serving as outer conductors are spirally wound from above a dielectric, and the plurality of conductive strands are connected to each other. It is wound at an angle of 8 degrees to 19 degrees with respect to the longitudinal direction of the coaxial cable. A plurality of conductive wires at an angle within a predetermined range. In the coaxial cable disclosed in Japanese Patent Laid-Open No. 20 0 3-0 9 2 0 31, a coaxial cable excellent in electrical characteristics such as a shielding effect is provided.

 In the coaxial cable described above, sufficient shielding characteristics are obtained by winding a metal tape as an outer conductor or a plurality of conductive strands on a dielectric layer at a predetermined angle. We are trying to reduce it.

 On the other hand, from the electronic equipment industry, etc., where the performance of equipment is increasing, it is flexible and has higher shielding characteristics, which can reduce attenuation and reduce fluctuations in attenuation. There is a strong demand for using a coaxial cable. Disclosure of the invention

 The present invention has been made in view of the various problems as described above. The object of the present invention is to have flexibility and a higher shielding characteristic, 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 A coaxial cable having a protective coating layer provided on the outer periphery of the layer, wherein the winding is composed of a winding band that winds the outer conductor layer between the outer conductor layer and the protective coating layer. A band layer is provided, and the wound band layer is wound at a predetermined angle with respect to a longitudinal axis direction of the coaxial cable.

Thus, in the coaxial cable of the present invention, the winding band is further wound from above the outer conductor layer of the coaxial cable. For this reason, the outer conductor layer is pressed by the winding band, so the outer conductor layer is tightened. As a result, the adhesion of the outer conductor layer is improved and the shielding characteristics are improved. In addition, since the outer conductor is tightened, it becomes 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. As a result, since the wound belt layer becomes a shield layer, two shields of the outer conductor layer and the wound belt layer are provided, and the shield characteristics can be further improved. In addition, in this coaxial cable, it is possible to stably maintain a state in which the shield characteristics are improved by closely contacting the wound belt 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. As a result, in the coaxial cable according to the present invention, the outer conductor can be tightly tightened by the wound belt layer while maintaining the production efficiency, and the shield characteristics can be improved.

 In the coaxial cable according to the present invention, the outer conductor layer is wound in a single horizontal direction. The coaxial cable of the present invention is characterized in that the outer conductor layer is double-rolled horizontally. Thus, in the coaxial cable of the present invention, whether the outer conductor layer is single-sided or double-sided, the outer conductor layer is tightened by winding the winding band from above. Therefore, even if the number of outer conductor layers is increased, the present invention can be applied. Brief Description of Drawings

FIG. 1 is a diagram showing a coaxial cable 1 according to an embodiment of the present invention. Fig. 2 is the first diagram showing the results of the shield test of coaxial cable 1. The

 FIG. 3 is a second diagram showing the result of the shield test of the coaxial cable 1.

 FIG. 4 is a diagram showing a test method for a winding test of the coaxial cable 1. FIG. 5 is a first diagram showing the results of the winding test of the coaxial cable 1.

 FIG. 6 is a second diagram showing the results of the winding test of the coaxial cable 1.

 FIG. 7 is a third diagram showing the results of the winding test of the coaxial cable 1.

 FIG. 8 is a first diagram showing the results of a soldering test of the coaxial cable 1 in which the outer conductor layer is double-sided.

 FIG. 9 is a second diagram showing the results of a winding test of the coaxial cable 1 in which the outer conductor layer is double-side-wrapped.

 FIG. 10 is a third view showing the results of a winding test of the coaxial cable 1 in which the outer conductor layer is double-side wound. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The embodiments described below do not limit the invention according to the claims, and all the combinations of features described in the embodiments are essential for the establishment of the present invention. Not exclusively.

First, the configuration of the coaxial cable 1 of the present embodiment will be described with reference to FIG. Here, in FIG. 1, FIG. 1 (a) is a perspective view of the coaxial cable 1 of the present embodiment, and FIG. 1 (b) is a sectional view of the coaxial cable 1 of the present embodiment. Fig. 1 (C) shows the winding of the coaxial cable 1 FIG.

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

 That is, the coaxial cable 1 is formed by twisting a plurality of conductors 1 1 a to form a center conductor 1 1, and using an extruder (not shown) on the outer periphery of the center conductor 1 1, a dielectric 1 2 a is extrusion coated to form dielectric layer 12. Then, a plurality of conductor strands 13 a are horizontally wound around the outer periphery of the dielectric layer 12 to form the outer conductor layer 13, and the outer periphery of the outer conductor layer 13 is, for example, a conductor strand. 1 In a direction opposite to the lateral winding direction of 3 a, a metallized tape, for example, ALPE T 14 a (winding band) is spirally wound to form a characteristic part of the present invention. Form. 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 material of the coaxial cable 1 is, for example, a silver-plated annealed copper wire of the conductive wire 1 la, and a material of the dielectric 1 2 a is a tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter simply referred to as FEP). ) The conductor wire 13a is made of tinned annealed copper wire, and the jacket 15 is made of FEP. Note that the material of the coaxial cable 1 of the present embodiment is not limited to the above-described materials, and other materials that are usually used for the coaxial cable can also be used. For example, it is possible to use other fluororesins such as polytetrafluoroethylene (PTFE) or terafluoroethylene monopearl fluoroalkyl vinyl ether copolymer (PFA) as the dielectric. is there. In the coaxial cable 1 of the present embodiment, the winding band layer 14 is The direction of rotation may be the same as the direction of horizontal winding of the conductor wire 13 3 a as long as the conductor wire 13 3 a horizontally wound as the outer conductor layer 13 3 is fastened.

 AL PET 14a is formed into a tape by laminating aluminum foil and polyethylene tephrate (hereinafter simply PET) via polyvinyl chloride (hereinafter simply PVC). It is what. The A LPET 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. 1 (c), the conductor wire 13a is laid on the outer conductor layer 13 as the outer conductor layer 13. The AL PET 14 a forming the wound belt layer 14 is spirally wound at a predetermined angle 0 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 wound belt layer 14, and the degree of adhesion between the conductor wires 13 3a of the outer conductor layer 13 is improved. Further, since the plurality of conductor strands 13 a are tightened by the wound belt layer 14, the conductor strips 13 a are kept in close contact with each other by the wound belt layer 14. Even if the coaxial cable 1 is bent, it is possible to prevent the conductor wires 13 a from being separated from each other at the bent portion. Since the wound belt layer 14 is formed of the AL PET 14a, the wound belt layer 14 itself also acts as a shield.

As a result, the coaxial cable 1 according to the present embodiment includes two layers having a shield effect, that is, the outer conductor layer 1 3 and the wound belt layer 14. Further, the outer conductor layer 1 3 Since the conductor wire 1 3 a is tightened by the wound belt layer 14, the adhesion between the conductor wires 1 3 a is improved, and the adhesion state is maintained, and the outer conductor layer is maintained. 1 3 More shield effect It becomes possible to raise.

 Next, in the coaxial cable 1 of the present embodiment, a test for specifying the range of the predetermined angle Θ for winding the wound belt layer 14 was conducted. This will be described with reference to FIG.

 In this test, the relationship between the predetermined angle 0 and the characteristic of the shielding effect is obtained to determine the range of the predetermined angle 0, and the relationship between the predetermined angle 0 and the attenuation amount is as follows. Two tests were conducted, a squeeze test to determine the range of the predetermined angle 0. Fig. 2 and Fig. 3 show the test results of the shield test, Fig. 4 shows the test method of the winding test, and Fig. 5 to Fig. 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 the test results of the shield test, and Fig. 3 is a diagram showing the test results of the shield test. In this shield test, four coaxial cables 1 with varying predetermined angle 0 for winding the wound belt layer 14 are adjusted to a length of 3 m to be test cables A to D. The amount of the signal inserted into cables A to D leaked outside of test cables A to D was measured by an absorption clamp method in which an RF (Radio Frequency) network analyzer was used. The inserted signal was sequentially changed from 0 Hz to 1 GHz, and the change in shielding effect was measured during that time. For comparison, a braided coaxial cable used in the past was also tested.

The configuration of the four test cables A to D used in this shield test is that the central conductor 1 1 is formed by twisting seven silver-plated annealed copper wires having an outer diameter of 0.12 mm. The outer periphery of 1 is coated with FEP to form a dielectric layer 12 so that the outer diameter is 0.9 mm. The outer diameter of the dielectric layer 12 is equal to the outer diameter of the conductor wire 13 a. 2 9 tinned annealed copper wires, coaxial, The outer conductor layer 13 is formed by laying on the cable at an angle of 9.6 degrees with respect to the longitudinal direction of the cable. Foil and thickness 1 2 μηι PET and thickness 2-3! ! ! ALPET 14a, which is stacked through the same, is wound spirally to form a wound belt layer 14. This test cable A to D has an outer diameter of 1, 37 mm.

 In addition, the conventional braided coaxial cable has a configuration in which a central conductor is formed by twisting seven silver-plated annealed copper wires with an outer diameter of 0.102 mm and the outer circumference of this central conductor is covered with FEP. A dielectric layer is formed so that the outer conductor layer has a thickness of 16 and a braided structure of 6 with an outer diameter of 0.05 mm tinned annealed copper wire on the outer periphery of the dielectric layer. This outer conductor layer is formed by extrusion coating a 0.12 mm thick FE P jacket on the outer periphery, and this conventional braided coaxial cable has an outer diameter of 1, 37 mm. Has been.

 In addition, the test cables A to D each change the angle 0 at which the winding band layer 14 is wound, and the test cable A has the winding band layer 14 with respect to the longitudinal axis direction of the coaxial cable 1. Test cable B has a winding band 14 of 25 degrees with respect to the longitudinal direction of the coaxial cable 1 and test cable C has a winding band 14 of 14 with the longitudinal direction of the coaxial cable 1. In contrast, the test cable D is formed by winding the wound belt layer 14 spirally at an angle of 40 degrees with respect to the longitudinal direction of the coaxial cable 1.

As is clear 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 a higher shielding effect as a whole than the braided type coaxial cable. I understand that. Also, when comparing test cables A to D, test cable A has a signal of 10 MHz. The shielding effect is 1 5 1.7 dB, the shielding effect is 18.5 dB when the signal is 10 OMH z, and the test cable B has a shielding effect when the signal is 10 MHz—52. The shielding effect when the signal is 100 MHz at 5 dB is 49.8 dB, and the test cable C has a shielding effect of 53.4 dB when the signal is 10 MHz. The shielding effect at 1 MHz is 50. O d B, and the test cable D has a shielding effect of 15.5 B when the signal is 10 MHz, and the shielding effect is 1 0 B when the signal is 10 MHz. 51. I d B.

 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 0 for winding the wound belt layer 14 is larger. I understand that. That is, from the result of the shield test, it can be said that the angle 0 for winding the wound belt layer 14 is preferably 20 degrees or more. However, when the winding angle Θ increases, the width of the ALPET 14 a of the winding band 14 becomes narrower in inverse proportion to the angle 0, so the productivity of the coaxial cable 1 decreases. For this reason, the upper limit of the angle 0 for winding the wound belt layer 14 is 50 degrees in consideration of productivity. Therefore, in the shield test, it can be said that the preferable angle Θ for winding the wound belt layer 14 is 20 degrees or more and 50 degrees or less. Next, the winding test will be described in detail with reference to FIG. 4 to FIG.

 FIG. 4 is a diagram for explaining the test method of the winding test. First, the test method of the winding test will be explained using Fig. 4. In the winding test, the test cable is wound around the pipe 20 with an outer diameter of 1 Omm with a spacing of 1 Omm 1 2 times, and two types of signals of 5 GHz and 6 GHz are inserted into this wound test cable. Then, the signal attenuation was measured.

In this winding test, the shield test described in Fig. 2 and Fig. 3 Two types of brazing tests were conducted: a test using the same test cables A to D and a test using test cables F to H different from the shield test. First, the results of tests 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 angle 0 of the wound belt layer 14, Fig. 7 FIG. 6 is a diagram showing the relationship between the fluctuation value of the attenuation amount in the winding test and the angle 0 of winding of the wound belt layer 14. In this winding test, the same test was performed on a braided coaxial cable that had been used for comparison.

 As is clear from Fig. 5, the attenuation of the braided coaxial cable is 3.667 dB / m at 5 GHz and 4.0 3 dB at 6 GHz. Test cable A to D, which has the characteristic configuration of coaxial cable 1. The attenuation of test cable A is 3.36 0 dB / m at 5 GHz and 3.6 at 6 GHz. 9 2 d BZm, and attenuation of test cable B is 5 GH zB temple (3.30 5 dB / m, 3.6 GHz at 6 GHz, 3.6 2 6 dB / m, The attenuation of one cable C is 3.2 3 3 dB / m at 5 GHz, and 3.5 5 4 dB BZm at 6 GHz, and the attenuation of the test cable D is 3 at 5 GHz. It is 3.5 5 0 d BZm at 1 92 dB and 6 GHz. 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 attenuation compared to the braided coaxial cable.

Further, as apparent from FIGS. 5 to 7, in the test cables A to D, the wound belt layer 14 is wound in a spiral shape at 40 degrees with respect to the longitudinal direction of the coaxial cable. Test cable D has the smallest value of attenuation and fluctuation of attenuation, and test cable A and test cable D have a difference of about 0.2 dB / m in attenuation. Arise. Therefore, the coaxial cable of this embodiment As can be seen from Table 1, the amount of attenuation is lower than that of a conventional coaxial cable, and the amount of attenuation is further reduced by increasing the angle Θ for winding the wound belt layer 14.

 Also, the difference between the attenuation of test cable C and the attenuation of test cable D is about 0.04 d Ζ ιπι, and the difference is small, and the fluctuation in attenuation is almost the same at 6 GHz. It's gone. From this, the attenuation can be reduced by the fact that when the angle Θ of winding of the wound belt layer 14 exceeds 30 degrees, the change in attenuation is almost flat. It turns out that it becomes a peak. Therefore, even if the angle Θ for winding the wound belt layer 14 is 40 degrees or more, the attenuation value does not change greatly, and it is thought that a good state can be maintained. To do. As described in the result of the shield test, the angle 0 for winding the wound belt layer 14 has an upper limit of 50 degrees in consideration of productivity.

 Further, in the coaxial cable 1 of the present embodiment, as can be seen from FIGS. 5 to 7, the winding band 1 that the attenuation is greatly improved as compared with the conventional one and the fluctuation amount is small. The winding angle Θ of 4 is about 25 degrees.

 From the results of the attenuation test, the angle 0 for winding the wound belt layer 14 is a lower limit of 25 degrees, and 50 degrees is the J limit. Then, when the amount of attenuation and productivity are taken into account, the changing force S of the amount of attenuation S is almost flat. 30 ° or more and 40 ° or less is the most preferable angle for winding the wound belt layer 14 You can say that. Next, a winding test using another test cable will be described in detail with reference to FIG. 8 to FIG.

Fig. 8 is a table showing the test results of the winding test using different test cables F to H, and Fig. 9 is the attenuation and winding band of the winding test using different test cables F to H. Fig. 10 shows the relationship between the wound angle 0 of layer 14 and Fig. 10 shows the fluctuation value of the amount of attenuation in the winding test using different test cables F to H and the winding. It is a figure which shows the relationship with the wound angle Θ of the belt layer 14.

 The configuration of the three test cables F to H used in this winding test is that the central conductor 1 1 is formed by twisting seven silver-plated annealed copper wires with an outer diameter of 0.079 mm. A dielectric layer 12 is formed on the outer periphery of FEP so as to have an outer diameter of 0.7 mm, and tin with an outer diameter of 0.05 mm corresponding to the conductor wire 1 3 a is formed on the outer periphery of the dielectric layer 12 The outer conductor layer 1 3 is formed by laying double laying on the 9 pcs of annealed copper wire at an angle of 8.3 degrees with respect to the longitudinal axis direction of the coaxial cable. 1 3 on the outer periphery of 10 / m thick aluminum foil and 1 2 μπι PET in thickness 2 to 3 111? A spiral belt layer 14 is formed by spirally winding AL PET 14a, which is laminated through a wire, and a jacket made of 0.12m thick FEP is formed on the outer periphery of the wound belt layer 14. 15 is formed by extrusion coating. The outer diameters of the test cables F to H are 1, 13 mm.

 Then, the test cables F to H are respectively changed in the angle Θ for winding the wound belt layer 14, and the test cable F is arranged so that the wound belt layer 14 is aligned with the longitudinal direction of the coaxial cable. 1 9 degrees, test cable G has a winding band 14 of 25 degrees with respect to the longitudinal axis of the coaxial cable, and test cable H has a winding band 14 of 32 with respect to the longitudinal axis of the coaxial cable. Each of them is spirally wound at an angle of degrees. In addition, the comparative test cable 減 衰 used in the attenuation test is one in which the wound cable layer 14 is not provided in the test cables F to H.

As can be seen from FIG. 8, the attenuation of the comparative test cable E is 4.940 d B / at 5 GHz and 5.58 d BZm at 6 GHz. In the test cables F to H having the characteristic configuration of 1, the attenuation of the test cable F is 4.21 dBZm at 5 GHz and 4.65 dB / m at 6 GHz. Cable G The attenuation is 4, 11 dB B Zm at 5 GH z B, 4.5 3 dB B Zm at 6 GHz, and the attenuation of test cable H is 4.0 5 dB at 5 GHz. It is 4.45 dBB Zm at Zm 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 a reduced attenuation as a whole as compared with the comparative test cable E. As is clear from FIGS. 8 to 10, in the test cables F to H, the wound belt layer 14 is spirally wound with 3 2 in the longitudinal direction of the coaxial cable. The rotating test cable H has the smallest amount of attenuation and variation in attenuation. The test cable F and the test cable H have about 0.2 dB Bm of attenuation. The difference occurs. 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-sided, the winding band layer 1 Rotate 4 It turns out that the amount of attenuation decreases more when angle Θ is increased.

 Also, the difference between the attenuation of test cable G and the attenuation of test cable H is about 0.06 dBB Zm, and the difference is small. There is almost no difference with cable H. From this, the attenuation is reduced because the change in attenuation is almost flat when the winding angle Θ is between 25 and 3 2 degrees, in other words, about 30 degrees. It can be seen that it reaches a certain level at about 30 degrees. Therefore, even if the angle Θ for winding the wound belt layer 14 is 32 degrees or more, the attenuation value does not change greatly, and it is thought that the good state can be maintained. . And as described in the results of the shield test, the angle Θ for winding the wound belt layer 14 has an upper limit of 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 FIG. 8 to FIG. 10, the attenuation is greatly improved as compared with the conventional one. As the amount of fluctuation decreases, the winding zone layer 14 turns Angle 0 is about 25 degrees.

 As described above, from the result of the attenuation test, the lower limit of the angle 0 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 account, the change in attenuation is almost flat. 30 degrees or more and 40 degrees or less are the most preferable angle for winding the wound belt layer 14. It can be said.

 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 the upper limit is 50 degrees from the viewpoint of productivity. It becomes. As a preferable range, 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. As described above, in the coaxial cable 1 of the present embodiment described above, since the outer conductor layer 13 is formed sideways by the conductor wire 1 3 a, it is rich in flexibility and compared with a conventional coaxial cable. It can be seen that it has a high shielding effect and has reduced attenuation. It can also be seen that by increasing the winding angle 0 of the wound belt layer 14, the shielding effect is further improved and the attenuation is further reduced. This is because, when the angle Θ for winding the wound belt layer 14 is increased, the force of tightening the outer conductor layer 1 3 by the corresponding wound belt layer 14 increases, so the conductor of the outer conductor layer 1 3 This is because the degree of adhesion between the strands 1 3 a is improved accordingly. If the close contact between the conductor wires 1 3 a is improved, it becomes difficult to form a gap between the conductor wires 1 3 a. Therefore, it becomes possible to prevent the shield effect from being reduced due to a gap between the conductor wires 1 3 a, and the shield effect is improved. Further, since the wound belt layer 14 is formed of ALPET 14a, the wound belt layer 14 itself also acts as a shield.

As a result, the coaxial cable 1 of the present embodiment includes two layers having a shielding effect, that is, the outer conductor layer 13 and the wound band layer 14. In addition, since the conductor wire 1 3 a of the outer conductor layer i 3 is fastened by the wound belt layer 14, the degree of adhesion between the conductor wires 1 3 a can be improved and the adhesion state can be maintained. Thus, the shielding effect of the outer conductor layer 13 can be further increased, and the attenuation can be further reduced.

 In the present embodiment, the wound belt layer 14 has been 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 can be used as long as the outer conductor layer can be tightened. Industrial applicability

 The coaxial cable of the present invention can be applied to any device. For example, it can be applied to electronic devices such as computers, computers, and mobile phones, and it can also be applied to control circuits for machines that need to be equipped with control devices such as automobiles and airplanes in narrow spaces.

Claims

The scope of the claims 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 wound band layer comprising a wound 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-sided. The coaxial cable according to any one of claims 1 to 3, wherein the outer conductor layer is double-lined.