Foamed Jacket Data Cable for Automotive Ethernet Crosstalk Reduction

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Solution Overview

Problem

Automotive Ethernet cables with unshielded data lines suffer from high-frequency signal interference and transmission losses due to external radiation and crosstalk, which existing technologies fail to adequately address, especially in cost-sensitive applications where complex shielding measures are not feasible.

Innovation Solution

A data cable design featuring a transmission core with a high proportion of air/gas surrounding the unshielded core, achieved through a foamed casing or spacer elements, which minimizes external interference and maintains a low material usage and weight by keeping adjacent cables at a sufficient distance, thereby reducing crosstalk effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If unshielded data lines are used in automotive Ethernet cables, then material usage and weight are reduced, but transmission quality deteriorates due to high-frequency signal interference and crosstalk

Engineering Contradiction:
Improvematerial usageVSAvoidtransmission quality
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent applies a foamed jacket material with cellular structure surrounding the unshielded data lines. The foam structure provides dielectric isolation and physical spacing between adjacent cables, reducing crosstalk and electromagnetic interference while maintaining the unshielded design. The porous foam material achieves both material efficiency and transmission quality by providing necessary isolation without solid shielding layers.

Inventive Principle:
Principle #31Porous materials

2Device complexity

If unshielded data lines are used, then manufacturing complexity and cost are reduced, but external interference and transmission losses increase

Engineering Contradiction:
Improveshielding structure complexityVSAvoidexternal interference
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical and electrical parameters of the jacket material by using foam with specific density, cell structure, and dielectric properties. These parameter changes enable the jacket to provide electromagnetic isolation and reduce interference without requiring complex shielding structures. The foam's dielectric constant and loss tangent are optimized to minimize signal attenuation while maintaining simplicity.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If adjacent cables are placed closer together, then cable harness density increases, but crosstalk effects worsen

Engineering Contradiction:
Improvecable harness spaceVSAvoidcrosstalk
Core Design Contradiction:
Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality enhancement by using the foamed jacket material specifically at the interface between adjacent cables. The foam provides localized dielectric isolation and physical separation where crosstalk occurs most, while allowing the cable harness to maintain high density elsewhere. This targeted approach reduces crosstalk without requiring uniform spacing throughout the entire harness.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design significantly improves transmission quality by minimizing external interference and maintaining low material and weight usage, allowing for efficient data transmission with reduced material costs and sensitivity to external energy inputs.

Implementation Method 1

The high proportion of air is preferably generated by the fact that the casing is foamed

Methodology Applied
Scientific EffectFoaming: Foam

Implementation Method 2

the undesired transmission of energy from one cable to another cable, or the radiation of high-frequency fields into the transmission system

Methodology Applied
Scientific EffectElectromagnetic isolation: Electromagnetic Induction

Data Source

PatentEP3103122B1Data cable
Publication Date: 2018.07.18 LEONI KABEL GMBH
  • EP3103122B1 patent drawingFigure 1~2
  • EP3103122B1 patent drawingFigure 3A~4C

AI summary

The aim of the invention is to achieve a good transmission quality for a data cable (2) used in particular for automotive Internet applications. To achieve this, the data cable (2) has a transmission core (4) consisting only of a single stranded conductor pair or of four conductors (6) stranded together together to form a quad. The transmission core (4) is surrounded by a jacket (14,18,26,28,30) having a high air content. Said jacket can be formed by a foamed sheath (14,26), or alternatively by at least one spacer element (18,28,30) which defines an annular sheath space comprising air gaps (22) around the transmission core (4).