Twisted Communication Cable Shielding to Suppress Suck-Out

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Solution Overview

Problem

Existing communication cables, such as shielded twisted pair (STP) and shielded parallel pair (SPP) wires, face challenges in flexibility due to uneven conductor-to-metal foil distances, leading to increased attenuation (suck-out) at specific frequencies.

Innovation Solution

A communication cable design featuring two-core communication wires twisted with a pitch of 20 mm or more and 60 mm or less, wrapped with a metal foil tape having an adhesion strength of 1.21 MPa or more, which improves flexibility and suppresses suck-out.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If two-core communication wires are twisted to improve flexibility, then flexibility is improved, but the distance between conductor and metal foil becomes uneven causing suck-out

Engineering Contradiction:
ImproveflexibilityVSAvoidsignal attenuation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The metal foil is wound around the twisted two-core communication wires before the twisting process is completed, ensuring that the foil is already in position to maintain even distance relationships. This preliminary action prevents the conductor-to-foil distance from becoming uneven during the twisting process, thereby suppressing suck-out while maintaining flexibility.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent specifies a twist pitch of 20 mm or more and 60 mm or less, and an adhesion strength of 1.21 MPa or more for the metal foil. By optimizing these parameters, the patent achieves a balance where the wires remain flexible enough for practical use while maintaining sufficient adhesion and even spacing to prevent signal attenuation issues.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If metal foil adhesion strength is increased to suppress suck-out, then signal attenuation is reduced, but the complexity of manufacturing increases

Engineering Contradiction:
Improvesignal attenuationVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent specifies a concrete adhesion strength threshold of 1.21 MPa or more for the metal foil. This quantitative parameter provides a clear manufacturing target that balances signal attenuation suppression with manufacturability. By setting this specific threshold rather than requiring excessively high adhesion, the patent achieves reliable signal transmission without overly complicating the manufacturing process.

Inventive Principle:
Principle #35Parameter changes

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 twisted two-core communication wires enhance flexibility, while the strong adhesion between the wires and the metal foil reduces suck-out, resulting in improved performance compared to traditional SPP and STP wires.

Implementation Method 1

a metal foil tape collectively covering the two-core communication wires and the drain wire. The metal foil tape is wound around the two-core communication wires with an adhesion strength of 1.21 MPa or more

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3813081B1Communication cable and wire harness
Publication Date: 2025.04.23 YAZAKI CORP
  • EP3813081B1 patent drawingFigure 1
  • EP3813081B1 patent drawingFigure 2~3
  • EP3813081B1 patent drawingFigure 4~5

AI summary

A communication cable includes two-core communication wires, a drain wire, and a metal foil collectively covering the two-core communication wires and the drain wire. The two-core communication wires are twisted, and the metal foil is wound around the two-core communication wires with an adhesion strength of 1.21 MPa or more. Preferably, the two-core communication wires are twisted with a twist pitch of 20 mm or more and 60 mm or less. The communication cable further may include a restraint formed of a resin coating extruded around the metal foil or a resin film laterally wound around the metal foil.