Differential signal cable

Abstract

The utility model relates to high-speed signal transmission, in particular to a differential signal cable, which comprises two core wires and a shielding layer. More than two peripheral air cavities which are vertically and bilaterally symmetrical about the two core wires are arranged in the peripheral area of the insulator, so that the effective dielectric constant and the dielectric loss of the insulator are reduced, and the insertion loss of the differential signal cable is further reduced.

Description

Technical Field

[0001] The utility model relates to high-speed signal transmission, in particular to a differential signal cable. Background Art

[0002] The existing high-speed differential cable structure is usually a dual-core coaxial transmission line structure. As the cable transmission rate requirements continue to increase, the low loss and reliability requirements for cables used in transmission links are also becoming increasingly higher. Figure 1 As shown, a high-speed differential cable includes two parallel conductors and a shielding layer 4 covering the two conductors. The conductors include a conductor 2 and an insulating medium 5 covering the conductor 2. Existing high-speed differential cables typically use a dense insulating material or a foamed insulating material as the insulating medium to increase transmission speed. While high-speed differential cables using dense insulating materials can meet reliability requirements, they suffer from high insertion loss. High-speed differential cables using foamed insulating materials have lower insertion loss but fail to meet reliability requirements. In summary, existing high-speed differential cables cannot achieve both low loss and high reliability. Utility Model Content

[0003] The purpose of the present utility model is to provide a differential signal cable, which solves the problem that existing high-speed differential cables cannot meet the requirements of high reliability and low loss at the same time. Under the premise of ensuring the high reliability of the cable, the dielectric constant of the insulating medium in the cable can be reduced, thereby reducing the insertion loss of the cable and further improving the transmission rate.

[0004] To achieve the above-mentioned objectives, the present invention provides a differential signal cable, comprising a core wire and a shielding layer, wherein the core wire comprises a dense insulator, the shielding layer completely fits and wraps around the outer surface of the insulator, the insulator having a central region and a peripheral region, two conductors being arranged in parallel in the central region, and more than two peripheral air cavities extending along the length direction of the cable are provided in the peripheral region, and the peripheral air cavities are symmetrically arranged about the center of the two conductors.

[0005] Furthermore, there are two peripheral air cavities, and the centers of the two peripheral air cavities are collinearly arranged with the centers of the two conductors.

[0006] Furthermore, there are six peripheral air cavities, including two peripheral air cavities whose centers are collinear with the centers of the two conductors and four peripheral air cavities symmetrically arranged about the conductors.

[0007] Furthermore, there are multiple peripheral air cavities distributed along the contour of the shielding layer.

[0008] Furthermore, the peripheral air cavities are densely distributed and their arrangement shape is consistent with the outline shape of the shielding layer.

[0009] Furthermore, a central air cavity is provided in the insulator at the midpoint of the line connecting the center points of the two conductors.

[0010] Furthermore, the outer contour of the insulator is in a racetrack shape.

[0011] Furthermore, the cross-sectional shapes of all the air cavities are circular or polygonal.

[0012] Furthermore, the insulator is FEP insulator, PFA insulator, ETFE insulator, PE insulator or PP insulator.

[0013] Furthermore, the insulator is an extruded insulator formed by integral extrusion.

[0014] It can be seen from the above technical solution that the present invention provides a pioneering differential signal cable, including a core wire and a shielding layer, wherein the core wire includes a dense insulator, and the integrated insulator made of a dense insulating material can ensure that the differential signal cable has high reliability. The shielding layer completely fits the outer surface of the wrapped insulator, and the insulator has a central area and a peripheral area. Since more than two peripheral air cavities are set in the peripheral area of ​​the insulator, the dielectric constant of the insulating medium is reduced by introducing air cavities in the insulating material, thereby reducing the insertion loss of the cable. While ensuring that the differential signal cable has high reliability, the insertion loss of the differential signal cable is reduced, and the transmission rate of the cable in the transmission link is improved. In addition, the peripheral air cavity in the peripheral area of ​​the insulator is set to be symmetrical about the two conductors in the upper and lower left and right directions, which is conducive to forming a support structure in the insulator, ensuring that the structure of the insulator is reliable when the cable is under stress, and can reduce the dielectric constant of the insulating medium while ensuring the stability of the dielectric constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a cross section of an existing high-speed differential signal cable;

[0016] Figure 2 This is a cross-sectional schematic diagram of a first embodiment of a differential signal cable of the present invention;

[0017] Figure 3 This is a cross-sectional schematic diagram of a second embodiment of a differential signal cable of the present invention;

[0018] Figure 4 This is a cross-sectional diagram of a third embodiment of a differential signal cable of the present invention;

[0019] Figure 5 This is a cross-sectional schematic diagram of a differential signal cable according to a third embodiment of the present utility model;

[0020] In the figure: 1. differential signal cable; 2. conductor; 3. insulator; 4. shielding layer; 31. middle area; 311. middle air cavity; 32. peripheral area; 321. peripheral air cavity; 5. insulating medium. DETAILED DESCRIPTION

[0021] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0022] The differential signal cable of the present invention is mainly aimed at a differential signal cable used in transmission links in the field of high-speed signal transmission. The existing high-speed differential signal cable consists of two core wires to form a differential signal cable. The insulation part covering the conductor of the core wire mostly adopts dense insulation material or foam insulation material. These two materials cannot balance the requirements of low loss and high reliability of the cable.

[0023] Therefore, the present invention provides a differential signal cable, which includes a core wire and a shielding layer. The core wire includes an insulator, and the shielding layer completely fits and wraps the outer surface of the insulator. Two conductors are arranged in parallel in the middle area of ​​the insulator, and the outer area is symmetrical about the center of the two conductors (that is, symmetrical about the intersection of two mutually perpendicular lines that cross each other, and the two mutually perpendicular lines are the center line connecting the two conductors and the median perpendicular line of the center line). An outer air cavity is provided. The insulator is made of a dense insulating material and is an integrated insulator, which ensures that the differential signal cable can have high reliability. In addition, by introducing an air cavity in the insulator, the dielectric constant of the insulating medium is reduced, thereby reducing the insertion loss of the cable and improving the transmission efficiency of the cable.

[0024] Based on the above main concepts, embodiments are provided below for illustration.

[0025] like Figure 2-5 As shown, the differential signal cable 1 in the embodiment includes a core wire as shown in the figure, which includes an insulator 3. The two conductors 2 in the core wire are arranged in parallel in a central region 31 of the insulator 3 (the inner region defined by the dashed line in the figure). The peripheral region 32 of the insulator 3 (the region outside the dashed line in the figure) is provided with a peripheral air cavity 321 symmetrically arranged above and below and left and right about the two conductors 2. By introducing the air cavity in the insulator 3, the equivalent dielectric constant of the insulation material is reduced, further reducing the loss of the insulation medium, thereby reducing the insertion loss of the differential signal cable.

[0026] like Figure 2-5As shown, the core wire includes an integrated insulator 3, which is made of a dense insulating material. The use of an integrated insulator can ensure that the insulator 3 has good dielectric constant consistency while ensuring the high reliability of the differential signal cable 1. The number of peripheral air cavities 321 is more than two, and the peripheral air cavities 321 are symmetrical about the two conductors 2. This air cavity setting method can not only keep the dielectric constant of the insulator 3 stable, but also form a supporting structure in the insulator 3, ensuring the structural stability of the insulating dielectric layer of the cable when it is subjected to force, increasing the toughness of the insulator 3, and making the cable less likely to be broken when stretched, bent or even squeezed.

[0027] In one embodiment, there are two peripheral air cavities 321, with the centers of the two peripheral air cavities 321 collinear with the centers of the two core wires. This embodiment optimizes the dielectric constant of the insulator 3 by providing a minimum number of peripheral air cavities 321 that meet the positional relationship requirements, thereby reducing the dielectric constant and improving the transmission rate of the cable to a certain extent.

[0028] Considering that the peripheral air cavity 321 can not only affect the dielectric constant of the insulator 3, but also form a supporting structure in the insulator 3, in a more preferred embodiment, there are six peripheral air cavities 321, including two peripheral air cavities 321 whose centers are collinear with the centers of the two conductors 2 and four peripheral air cavities 321 symmetrically arranged about each conductor 2.

[0029] In another embodiment, there are multiple peripheral air cavities 321, which are distributed in the peripheral area of ​​the insulator 3 along the contour of the shielding layer 4. In a more preferred embodiment, the peripheral air cavities 321 in the peripheral area 32 of the insulator 3 are densely distributed, and their arrangement shape is consistent with the contour of the shielding layer 4. This differential signal cable is lighter, has a smaller bending radius, and is more flexible than existing high-speed differential signal cables.

[0030] In a more preferred embodiment, a central air cavity 311 is further provided in the central region 31 of the insulator 3 of the differential signal cable 1 . Specifically, a central air cavity 311 is further provided at the midpoint of the line connecting the center points of the two core wires.

[0031] Since the peripheral air cavity 321 is symmetrical about the two conductors in up-down and left-right directions, and when the peripheral air cavity 321 is multiple, the outer profile shape and size of the insulator 3 should meet the following conditions: firstly, the distance between the two conductors 2 arranged in parallel in the middle region 31 of the insulator 3 should be always stable, and secondly, the peripheral air cavity 321 distributed along the profile of the shielding layer 4 should be maximally accommodated on the peripheral region 32 of the insulator 3. Based on this, in an embodiment, the outer profile of the insulator 3 is a racetrack shape. Compared with the core wire with the insulator of other shapes, the core wire with the racetrack-shaped insulator with air cavity is more symmetrical and thus has better signal transmission function.

[0032] The middle air cavity 311 and the peripheral air cavity 321 distributed on the insulator 3 are holes parallel to the two conductors 2, and in any cross section of the core wire, the shape of the air cavity is not limited and can be uniformly set as any one of a circle, a rectangle, a polygon, etc. under the premise of process realization.

[0033] In order to improve the consistency of the dielectric constant of the insulator of the differential signal cable 1, ensure the material stability of the differential signal cable 1, and make the differential signal cable 1 not be affected by the change of the material structure under the conditions of bending, folding, etc. to affect the performance of the cable, in an embodiment, the insulator 3 is an extruded insulator extruded integrally, and the insulator 3 covering the two conductors 2 is the insulator produced at the same time in the same processing environment. The insulator 3 can adopt one of FEP, PFA, ETFE, PE, and PP.

[0034] The above is only a preferred embodiment of the present application, and is not used to limit the present application, and the patent protection scope of the present application is subject to the claims, and any equivalent structural changes made according to the content of the specification and the drawings of the present application should also be included in the protection scope of the present application.

Claims

1. A differential signal cable, characterized in that: The invention comprises a core wire and a shielding layer (4), wherein the core wire comprises a dense insulator (3), the shielding layer (4) completely fits and wraps around the outer surface of the insulator (3), the insulator (3) comprises a central region (31) and a peripheral region (32), two conductors (2) are arranged in parallel in the central region (31), and two or more peripheral air cavities (321) extending along the length direction of the cable are provided in the peripheral region (32), and the peripheral air cavities (321) are symmetrically arranged about the centers of the two conductors.

2. The differential signal cable according to claim 1, wherein: There are two peripheral air cavities (321), and the centers of the two peripheral air cavities (321) are arranged collinearly with the centers of the two conductors.

3. The differential signal cable according to claim 1, wherein: There are six peripheral air cavities (321), including two peripheral air cavities (321) whose centers are collinear with the centers of the two conductors (2), and four peripheral air cavities (321) that are symmetrically arranged about each conductor (2).

4. The differential signal cable according to claim 1, wherein: There are multiple peripheral air cavities (321) distributed along the contour of the shielding layer (4).

5. The differential signal cable according to claim 4, wherein: The peripheral air cavities (321) are densely distributed and their arrangement shape is consistent with the outline shape of the shielding layer (4).

6. The differential signal cable according to any one of claims 1 to 5, characterized in that: A central air cavity (311) is also provided in the insulator (3) at the midpoint of the line connecting the center points of the two conductors (2).

7. The differential signal cable according to any one of claims 1 to 5, characterized in that: The outer contour of the insulator (3) is in the shape of a racetrack.

8. The differential signal cable according to claim 6, wherein: The cross-sectional shapes of all air cavities are circular or polygonal.

9. The differential signal cable according to any one of claims 1 to 5, wherein: The insulator (3) is an FEP insulator, a PFA insulator, an ETFE insulator, a PE insulator, or a PP insulator.

10. The differential signal cable according to any one of claims 1 to 5, characterized in that: The insulator (3) is an extruded insulator formed by integral extrusion.

Images