WO2018120058A1

WO2018120058A1 - Shielded cable assembly

Info

Publication number: WO2018120058A1
Application number: PCT/CN2016/113593
Authority: WO
Inventors: 傅文汇
Original assignee: 德尔福派克电气系统有限公司
Priority date: 2016-12-30
Filing date: 2016-12-30
Publication date: 2018-07-05

Abstract

A cable assembly (10), the cable assembly being able to transmit signals on a single pair of conductors at the speed of 100 megabits per second. The characteristic impedance of the cable is 90 to 110 ohms and can support data transmission according to the Ethernet protocol. The cable assembly (10) comprises a pair of conductors (12A, 12B), shields (20, 24) surrounding the conductors (12A, 12B), and fillers (18A, 18B) being configured to maintain the gap between the conductors (12A, 12B) and the gaps between the conductors (12A, 12B) and the shields (20, 24). The conductors (12A, 12B) are configured to provide low resistance, and insulators (14A, 14B) surrounding the conductors (12A, 12B) are configured to provide low relative dielectric constant.

Description

Shielded cable assembly

Technical field

The present invention generally relates to shielded cable assemblies, and more particularly to shielded cable assemblies designed to transmit digital electrical signals having a data transmission rate of 100 megabits per second (Mb/s) or higher.

Background technique

The increase in the speed of digital data processing has led to an increase in the speed of data transmission. Transmission media for connecting electronic components to digital data processors must be constructed to efficiently transmit high speed digital signals between various components of a motor vehicle. Infotainment systems and other electronic systems in automobiles and trucks are beginning to demand cables capable of carrying high data rate signals. Currently, Controller Area Network (CAN) bus technology is widely used for data transmission in motor vehicles. However, the CAN bus has a maximum data transfer speed of only 1 Mbps. The CAN bus cannot meet the data transmission requirements of new applications such as entertainment systems attached to motor vehicles, and thus Ethernet bus technology with a data transmission rate of 100 Mbps is continuously applicable to motor vehicles.

Automotive grade cables must not only meet environmental requirements (such as heat and humidity resistance), they must also be flexible enough to be routed in the vehicle wiring harness, and have a small mass to help meet the fuel economy needs of the vehicle. Thus, there is a need for a data cable having a data transmission rate sufficient to support Ethernet bus technology, which has a small mass and is sufficiently flexible to be wrapped in a vehicle harness. While the particular application given for the cable assembly is a car, such a cable may also have other applications, such as aeronautical, industrial control, or other data communications.

The subject matter discussed in the Background section should not be considered as prior art merely because it is referred to in the background section. Similarly, problems mentioned in the background section or associated with the subject matter of the background section should not be considered as recognized in the prior art. The topics in the background section represent only different implementation methods, and the topics themselves may be creative.

Summary of the invention

In accordance with an embodiment of the present invention, a cable assembly configured to transmit electrical signals is provided. The cable assembly includes a first cable, the first cable is formed by a first conductor, the first conductor is axially surrounded by the first insulator, and the cable assembly includes a second cable, the second cable is The second conductor is formed, and the second conductor is axially surrounded by the second insulator. The first conductor and the second conductor are comprised of at least 99.9% copper The copper-based material is formed. The relative dielectric constant of the first insulator and the second insulator is in the range of 2.5 to 2.7. The cable assembly also includes a first filler member and a second filler member, each of the first filler member and the second filler member having an elongated cylindrical shape. The first cable and the second cable and the first filler and the second filler are twisted with each other such that the first cable is opposite the second cable and the first filler is opposite the second filler. The cable assembly also includes an inner shield conductor at least partially axially surrounding the first and second cables and the first and second filler members, at least partially axially surrounding the inner shield conductor and electrically interconnecting the inner shield conductor a connected outer shield conductor and a ground conductor intermediate the inner shield conductor and the outer shield conductor and in electrical communication with the inner shield conductor and the outer shield conductor. The cable assembly has the feature of having a differential insertion loss of less than 1.0 decibel (dB) for a signal having a signal frequency content of less than 1 megahertz (MHz) and less than 2.6 for a signal having a signal frequency content between 1 MHz and 10 MHz. Differential insertion loss of dB with differential insertion loss of less than 4.9 dB for signals with signal frequency content between 10 MHz and 33 MHz, and differential insertion loss of less than 7.2 dB for signals with signal frequency content between 33 MHz and 66 MHz .

The inner shield conductor may be formed of an aluminized film wrapped around the first cable and the second cable and the first filler and the second filler, and wherein the lateral length of the inner shield conductor covers the first cable and the second wire The cable and at least 100 percent of the circumference of the first filler and the second filler. The outer shield conductor can be formed from a braided copper cable. The braided copper wire covers at least 90 percent of the inner shield conductor.

The cable assembly can also include an insulative jacket axially at least partially surrounding the outer shield conductor and a separate member formed from the nonwoven fabric disposed between the insulative jacket and the outer shield conductor.

The lay length of the first cable twisted around the second cable may be in the range of 10 to 20 times the diameter of the first conductor and the second conductor. The first conductor and the second conductor may be formed of 7 strands and have an outer diameter of 0.85 mm. The lay length can be in the range of 8.5 to 17.0 mm. The first insulator and the second insulator may be formed of a cross-linked polyethylene material having a thickness of between 0.2 mm and 0.235 mm. The outer diameter of the first filler member and the second filler member may be in the range of 0.8 to 1.0 mm. The first filler and the second filler may be formed of a polyethylene material. The first conductor and the second conductor can be compressed to 98% of their original diameter.

The characteristic impedance of the cable assembly can range from 90 to 110 ohms.

The cable assembly can have the following features: a return loss of less than 18 dB for signals having a signal frequency content between 1 MHz and 20 MHz, and less than 18-10 for signals having a signal frequency content between 20 MHz and 66 MHz. × log ₁₀ (f/20MHz) dB return loss, where f is the highest frequency of the signal. The cable assembly can have the following features: a mode conversion of less than 43 dB for signals having a signal frequency content between 1 MHz and 33 MHz, and less than 43-20× for signals having a signal frequency content between 33 MHz and 200 MHz. Mode conversion of log ₁₀ (f/33MHz) dB. The cable assembly can have the following characteristics: power and external near-end crosstalk (PSANEXT) losses greater than 31.5-10 x log ₁₀ (f/100 MHz) dB. The cable assembly can have the following characteristics: power and far-end external attenuation-to-crosstalk ratio (PSAACRF) losses greater than 16-20 x log ₁₀ (f/100 MHz) dB, where f is the highest frequency of the signal.

Further features and advantages of the present invention will become apparent from the Detailed Description of the <RTIgt;

DRAWINGS

The invention will now be described by way of example with reference to the accompanying drawings in which:

1 is a side cross-sectional view of a cable assembly having a stranded conductor, in accordance with one embodiment;

2 is a cross-sectional view of the cable assembly of FIG. 1 in accordance with an embodiment;

3 is a performance specification table of the cable assembly of FIG. 1 in accordance with one embodiment.

detailed description

Presented herein is a shielded cable assembly capable of carrying digital signals at rates up to 100 megabits per second (Mbps) to support Ethernet transport protocols. The cable assembly includes a pair of conductors (pairs), conductive sheets, and braided conductors to isolate the pairs from electromagnetic interference and determine the characteristic impedance of the cable. The wire pairs are wrapped into a dielectric strip that helps provide a consistent radial distance between the wire pair and the shield. If the pair is twisted, the strap can also help maintain a consistent twist angle between the pairs. A consistent radial distance and consistent twist angle between the pair and the shield provides a cable assembly with a more consistent impedance.

1 and 2 show a non-limiting example of a cable assembly 10. The cable assembly 10 includes a single pair of conductors including a first conductor 12A and a second conductor 12B. The first conductor 12A and the second conductor 12B are formed of a high purity copper-based material that includes at least 99.9% of copper by weight. In the example shown in Figures 1 and 2, the first conductor 12A and the second conductor 12B of the cable assembly 10 are each composed of seven strands in a symmetrical configuration conforming to the ISO 6722 specification, and the ISO 6722 specification is incorporated by reference. This article. Each of the strands of the first conductor 12A and the second conductor 12B may have the following characteristics: a maximum diameter of 0.26 millimeters (mm). The first conductor 12A and the second conductor 12B are compressed to 98% of their original dimensions such that the maximum outer diameter of each conductor is 0.85 mm.

Each of the first conductor 12A and the second conductor 12B is enclosed in a first dielectric insulator and a second dielectric insulator, respectively referred to as a first insulator 14A and a second insulator 14B, to form a first line, respectively. Cable 16A and second cable 16B. In addition to the portion that is removed at the end of the cable for terminating the cable assembly 10, the first insulator 14A and the second insulator 14B travel through the entire length of the cable assembly 10. The first insulator 14A and the second insulator 14B are formed of a flexible dielectric material such as crosslinked polyethylene (XLPE). The first insulator 14A and the second insulator 14B may be characterized by a thickness of between 0.2 mm and 0.235 mm such that the insulator has a relative dielectric constant of 2.5 to 2.7.

The cable assembly 10 further includes a first filler 18A and a second filler 18B, each having an elongated cylindrical shape, except for terminating the cable assembly 10 in the cable At the portion where the ends are removed, the first filler 18A and the second filler 18B travel through the entire length of the cable assembly 10. The first filler 18A and the second filler 18B have an outer diameter of 0.8 to 1.0 mm. The first filler 18A and the second filler 18B are formed of a flexible dielectric material such as XLPE or high density polyethylene (HDPE).

The first cable 16A and the second cable 16B and the first filler 18A and the second filler 18B are twisted with each other such that the first cable 16A is opposite to the second cable 16B, and the first filler 18A and the second Filler 18B is opposite. The first cable 16A and the second cable 16B and the first and

second filler members

18A, 18B are twisted longitudinally, for example, every 15 to 20 mm in length L. Twisting the first cable 16A and the second cable 16B provides the benefit of reducing low frequency electromagnetic interference from the signal carried by the center pair. The first filler 18A and the second filler 18B help to maintain a space between the first cable 16A and the second cable 16B. When the first cable 16A and the second cable 16B are twisted, the first filler 18A and the second filler 18B may also maintain a twist angle 之间 between the first cable 16A and the second cable 16B (see figure) 3) Consistent.

The first filler 18A and the second filler 18B also provide the advantage of maintaining a consistent radial distance between the first conductor 12A and the second conductor 12B and the inner shield 20. The shielded twisted pair cable of the prior art only uses air as a dielectric between the twisted pair and the shield. The distance between the first conductor 12A and the second conductor 12B and the inner shield 20 and the effective twist angle 第一 of the first conductor 12A and the second conductor 12B affect the impedance of the cable assembly. Thus, a cable assembly having a more uniform radial distance between the first conductor 12A and the second conductor 12B and the inner shield 20 provides a more consistent impedance. The more consistent torsion angle 第一 of the first conductor 12A and the second conductor 12B also provides a more consistent impedance.

In addition to the portion that can be removed at the end of the cable for terminating the cable assembly 10, the first cable 16A and the second cable 16B and the first and

second filler members

18A, 18B are thereafter referred to as Inner shield The conductive sheet of the member 20 is axially surrounded. The inner shield 20 can be wrapped longitudinally in a single layer to surround the strip 112 such that the inner shield 20 forms a single seam that is generally parallel to the center pair of the first conductor 12A and the second conductor 12B. Alternatively, the inner shield 20 may be helically wrapped or spirally wrapped around the first cable 16A and the second cable 16B and the first filler 18A and the second filler 18B. The edges of the seam of the inner shield 20 may overlap such that the inner shield 20 covers at least 100 percent of the outer surface of the belt 112. The inner shield 20 is formed of a flexible conductive material such as an aluminum-plated biaxially oriented PET film. Biaxially oriented polyethylene terephthalate film is commonly referred to as its trade name MYLAR, and an aluminized biaxially oriented PET film will hereinafter be referred to as an aluminized MYLAR film. The aluminized MYLAR film has a conductive aluminum coating applied to only one major surface; the other major surface is non-aluminized and thus non-conductive. The design, construction and source of single side aluminized MYLAR films are well known to those skilled in the art. The non-aluminized surface of the inner shield 20 is in contact with the first cable 16A and the second cable 16B and the first filler 18A and the second filler 18B. The inner shield 20 can have the following features: a minimum thickness of the aluminum layer having a thickness of about 0.05 mm and an aluminized MYLAR film of 0.025 mm.

As shown in FIGS. 1 and 2, the cable assembly 10 additionally includes a ground conductor, hereinafter referred to as a drain cable 22, which is disposed outside of the inner shield 20. The drain cable 22 extends along the entire length of the cable assembly 10 and is in intimate or at least in electrical communication with the aluminized outer surface of the inner shield 20. In the example of Figures 1 and 2, the drain cable 22 of the cable assembly 10 includes seven strands. Each strand of the drain cable 22 has the following characteristics: a maximum diameter of 0.26 millimeters (mm). The drain wire 22 has the following features: a maximum outer diameter of 0.9 mm. The drain wire 22 is formed of tinned copper wire. Those skilled in the art are well familiar with the design, construction, and source of tinned copper conductors.

As shown in FIGS. 1 and 2, in addition to the portion that can be removed at the end of the cable for terminating the cable assembly 10, the cable assembly 10 also includes a braid that is hereinafter referred to as the outer shield 24. The wire conductor, outer shield 24 encloses inner shield 20 and drain wire 22. The outer shield 24 is formed from a plurality of braided conductors such as copper or tin plated copper. When used herein, tin refers to elemental tin or tin based alloys. The design, construction and source of the braided conductors used to provide such outer shields are well known to those skilled in the art. The outer shield 24 is in intimate or at least in electrical communication with both the inner shield 20 and the drain cable 22. The cable forming the outer shield 24 covers at least 90 percent of the outer surface of the inner shield 20.

The cable assembly 10 shown in Figures 1 and 2 also includes an outer dielectric insulator, hereinafter referred to as a jacket 26. The jacket 26 encloses the outer shield 24 except at the portion that is removed at the end of the cable for terminating the cable assembly 10. The jacket 26 forms an outer insulating layer that provides electrical insulation for the cable assembly 10 And environmental protection. The jacket 26 is formed from a flexible dielectric material such as 105 polyvinyl chloride (PVC), 125 PVC or XLPE. The sheath 26 has the following features: a minimum thickness of 0.33 mm.

The cable assembly 10 shown in Figures 1 and 2 also includes a separate layer between the outer shield 24 and the jacket 26, hereinafter referred to as the separator 28. The separator 28 is formed of a nonwoven material and is configured to facilitate stripping the sheath 26 from the cable assembly 10 when the cable assembly 10 is terminated.

As shown in FIG. 3, the cable assembly 10 has the feature that the characteristic impedance is in the range of 90 to 110 ohms. For signals having a signal frequency content between 1 MHz and 20 MHz, cable assembly 10 has a return loss of less than 18 dB, while for signals having a signal frequency content between 20 MHz and 66 MHz, cable assembly 10 has less than 18-10. × log ₁₀ (f/20MHz) dB return loss, where f is the highest frequency of the signal. For signals having a signal frequency content between 1 MHz and 33 MHz, cable assembly 10 has a mode transition of less than 43 dB, while for signals having a signal frequency content between 33 MHz and 200 MHz, cable assembly 10 has less than 43-20 x Mode conversion of log ₁₀ (f/33MHz) dB. The power and external near-end crosstalk (PSANEXT) loss of cable assembly 10 is greater than 31.5-10 x ₁₀ (f/100 MHz) dB. The power and far-end external attenuation crosstalk ratio (PSAACRF) loss of the cable assembly 10 is greater than 16-20 x log ₁₀ (f/100 MHz) dB, where f is the highest frequency of the signal.

Thus, a cable assembly 10 is provided. The cable assembly 10 is capable of reliably carrying digital signals, i.e., transmitting signals at rates up to 100 megabits per second (Mbps) with low signal loss, thereby enabling support of Ethernet transport protocols. The cable assembly 10 is capable of transmitting signals on a single pair of conductors at this rate without transmitting signals on multiple twisted pairs that are capable of supporting similar data transmission rates as used in other high speed cables, such as multi-stranded pairs. Category 7cable. The use of a single pair of wires in the cable assembly 10 provides the advantage of eliminating the possibility of crosstalk between pairs of twisted pairs in other cable assemblies having multiple twisted pairs. The single pair of wires in the cable assembly 10 also reduces the quality of the cable assembly 10; this is an important factor in weight sensitive applications such as automotive and aerospace. The materials and construction of the first conductor 12A and the second conductor 12B provide a low resistance signal path. The material and thickness of the first insulator 14A and the second insulator 14B provide a low relative dielectric constant of 2.5 to 2.7. The first filler 18A and the second filler 18B between the first cable 16A and the second cable 16B and the inner shield 20 help to maintain the space between the first conductor 12A and the second conductor 12B and the inner shield 20 The uniform radial distance, especially when the cable is bent as needed when wiring the cable assembly 10 in the automotive wiring assembly. Maintaining a consistent radial distance between the first conductor 12A and the second conductor 12B and the inner shield 20 provides consistent cable impedance and a more reliable data transfer rate. Likewise, especially when the cable assembly 10 is guided at an angle that would normally cause cable separation between the first cable 16A and the second cable 16B. The first filler 18A and the second filler 18B help maintain a twist angle 之间 between the first cable 16A and the second cable 16B when bent through the vehicle. This also helps to provide consistent impedance. Thus, the cable assembly 10 having consistent impedance and performance characteristics and capable of transmitting digital data at a speed of 100 Mb/s or higher even when the cable assembly 10 is bent is a combination of components rather than any one of the specific components. Provided, these members are, for example, the first conductor 12A and the second conductor 12B, the first insulator 14A and the second insulator 14B, and the first filler 18A and the second filler 18B.

Although the present invention has been described in its preferred embodiments, the invention is not intended to be limited thereto, but is limited only by the scope of the appended claims. Moreover, the use of the terms first, second, etc. does not denote any order of importance, but rather the terms first and second are used to distinguish different components. Moreover, the use of an indefinite article does not indicate a limitation of the quantity, but rather indicates that there is at least one referenced item.

Claims

A cable assembly (10) comprising:

a first cable (16A), the first cable being composed of a first conductor (12A), the first conductor being surrounded by a first insulator;

a second cable (16B), the second cable being composed of a second conductor (12B), the second conductor being surrounded by a second insulator, wherein the first conductor (12A) and the second conductor (12B) is formed of a copper-based material including at least 99.9% of copper, and wherein the first insulator (14A) and the second insulator (14B) have a relative dielectric constant in a range of 2.5 to 2.7;

a first filling member (18A) and a second filling member (18B), each of the first filling member and the second filling member having an elongated cylindrical shape, wherein the first cable (16A) and the The second cable (16B) and the first filler (18A) and the second filler (18B) are twisted with each other such that the first cable (16A) and the second cable ( 16B) opposite, and the first filling member (18A) is opposite to the second filling member (18B);

Inner shield (20) conductor, the inner shield conductor at least partially axially surrounding the first cable (16A) and the second cable (16B) and the first filler (18A) and The second filling member (18B),

An outer shield (24) conductor, the outer shield conductor at least partially axially surrounding the inner shield (20) conductor and in electrical communication with the inner shield (20) conductor;

a grounding conductor located between the inner shield (20) conductor and the outer shield (24) conductor and electrically connected to the inner shield (20) conductor and the outer shield (24) conductor Connected, wherein the cable assembly (10) has a differential insertion loss of less than 1.0 decibel (dB) for a signal having a signal frequency content of less than 1 megahertz (MHz) for a signal frequency content between 1 MHz and 10 MHz The signal has a differential insertion loss of less than 2.6 dB, a differential insertion loss of less than 4.9 dB for signals having a signal frequency content between 10 MHz and 33 MHz, and less than 7.2 for signals having a signal frequency content between 33 MHz and 66 MHz. Differential insertion loss of dB.
The cable assembly (10) according to claim 1, wherein said inner shield (20) conductor is surrounded by said first cable (16A) and said second cable (16B) An aluminized film wrapped around the first filler (18A) and the second filler (18B) is formed such that a slit formed by the conductor of the inner shield (20) is substantially parallel to the cable assembly (10) a longitudinal axis, and wherein a lateral length of the inner shield (20) conductor covers the first cable (16A) and the second cable (16B) and the first fill At least 100 percent of the circumference of the member (18A) and the second filler member (18B).
The cable assembly (10) according to claim 1 or 2, wherein the outer shield (24) conductor is formed of a braided copper cable, and wherein the braided copper cable covers the At least 90 percent of the inner shield (20) conductor.
The cable assembly (10) according to any of the preceding claims, wherein the first cable (16A) is twisted around the second cable (16B) at the first One conductor (12A) and the second conductor (12B) are in the range of 10 to 25 times the diameter.
The cable assembly (10) according to any of the preceding claims, wherein the cable assembly further comprises:

An insulating sheath (26) axially at least partially surrounding the outer shield (24) conductor;

A separating member (28) formed of a nonwoven fabric disposed between the insulating sheath (26) and the outer shield (24) conductor.
A cable assembly (10) according to any of the preceding claims, wherein the first conductor (12A) and the second conductor (12B) are formed by 7 strands and have an outer diameter of 0.85 mm Wherein the lay length is in the range of 15 to 20 mm, and wherein the first insulator (14A) and the second insulator (14B) are made of cross-linked polyethylene material having a thickness of between 0.2 mm and 0.235 mm form.
A cable assembly (10) according to any of the preceding claims, wherein the first filler (18A) and the second filler (18B) have an outer diameter of 0.8 to 1.0 mm Within the scope, and wherein the first filler (18A) and the second filler (18B) are formed of a polyethylene material.
A cable assembly (10) according to any of the preceding claims, wherein the first conductor (12A) and the second conductor (12B) are compressed to the first conductor and the 98% of the original diameter of the second conductor.
A cable assembly (10) according to any of the preceding claims, characterized in that the characteristic impedance of the cable assembly (10) is in the range of 90 to 110 ohms.
A cable assembly (10) according to any of the preceding claims, characterized in that the cable assembly (10) has the feature that for signals having a signal frequency content between 1 MHz and 20 MHz, having a smaller 18dB of return loss, and for signals having a signal frequency content between 20MHz and 66MHz, with a return loss of less than 18-10 x log 10 (f/20MHz) dB, where f is the highest frequency of the signal.
A cable assembly (10) according to any of the preceding claims, characterized in that the cable assembly (10) has the feature that for signals having a signal frequency content between 1 MHz and 33 MHz, having a smaller 43dB mode conversion, and for signals having a signal frequency content between 33MHz and 200MHz, having a mode conversion of less than 43-20 x log 10 (f/33 MHz) dB, where f is the highest frequency of the signal.
A cable assembly (10) according to any of the preceding claims, characterized in that the cable assembly (10) has the following features: power and far-end external attenuation crosstalk ratio (PSANEXT) loss greater than 31.5-10 × log 10 (f/100MHz) dB, where f is the highest frequency of the signal.
A cable assembly (10) according to any of the preceding claims, characterized in that the cable assembly (10) has the following features: power and far-end external attenuation-to-crosstalk ratio (PSAACRF) loss greater than 16- 20 × log 10 (f / 100MHz ) dB, where, f is the maximum frequency of the signal.