Composite Aramid-Copper Cable Shielding for Weight and EMI Reduction

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Solution Overview

Problem

Conventional coaxial cables with braided copper wire shields face issues of flexibility vs. performance trade-offs and weight, leading to electromagnetic radiation leakage and increased transportation costs due to their weight.

Innovation Solution

A coaxial cable design featuring a conductive core surrounded by a dielectric material, a braided tinned copper shielding, and an additional shielding of aramid fibers with nickel physical vapor deposition, which are braided to cover at least 80% of the copper shielding, providing enhanced electromagnetic shielding while reducing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thin metal foil shield covered by a copper wire braid is used, then electromagnetic shielding performance is improved, but cable flexibility deteriorates

Engineering Contradiction:

Improveelectromagnetic shielding performanceVSAvoidcable flexibility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent combines aramid fibers with nickel coating to create a composite shielding material that replaces traditional copper wire braid. This composite structure maintains electromagnetic shielding effectiveness while significantly improving cable flexibility, as aramid fibers are inherently more flexible than rigid metal foils and coated copper structures.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent substitutes the mechanical copper wire braid structure with an aramid fiber-based shielding system. The aramid fibers provide the necessary mechanical flexibility while the nickel coating and braided configuration maintain the electromagnetic shielding function, replacing the traditional metal-centric approach with a fiber-reinforced composite approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a double-layer shield with copper wire braid is used, then electromagnetic shielding performance is improved, but cable weight increases

Engineering Contradiction:

Improveelectromagnetic shielding performanceVSAvoidcable weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent employs aramid fibers coated with nickel as a composite shielding material that replaces traditional copper wire braid. Aramid fibers have a significantly lower density than copper, resulting in substantial weight reduction while maintaining shielding effectiveness through the combination of fiber structure and conductive nickel coating.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters of the shielding layer by transitioning from dense metal (copper) to lightweight composite (aramid fiber with nickel coating). This parameter change maintains the electrical and electromagnetic properties necessary for shielding while dramatically reducing the mass per unit length of the cable.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If braided copper wire is used for shielding, then cable flexibility is maintained, but shielding effectiveness deteriorates due to gaps in the shield layer

Engineering Contradiction:

Improvecable flexibilityVSAvoidshielding effectiveness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent uses aramid fibers coated with nickel to create a composite shielding material that can be braided with tighter spacing and smaller gaps than traditional copper wire. The flexible aramid fiber base allows for more compact braid configurations, reducing inter-ststrand gaps while maintaining overall cable flexibility.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies nickel coating locally on the aramid fiber surface to create conductive pathways in the braid structure. This localized conductive layer fills the gaps between fibers more effectively than solid copper wire, providing continuous electromagnetic shielding while the underlying aramid fiber structure maintains cable flexibility.

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 aramid fiber shielding significantly improves electromagnetic shielding performance and reduces cable weight by approximately 30% compared to traditional double metallic braided shields, maintaining flexibility and enhancing shielding effectiveness across a wide frequency spectrum.

Implementation Method 1

a second shielding comprising aramid fibers having nickel physical vapor deposited thereon

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentUS9842673B2Composite high performance cables

Publication Date: 2017.12.12 MINNESOTA WIRE & CABLE

AI summary

In one embodiment, a cable includes a conductive core and a dielectric material surrounding the conductive core along a length of the cable. The cable also includes a first shielding comprising braided tinned copper and a second shielding comprising aramid fibers having nickel physical vapor deposited thereon. The aramid fibers are braided about the first shielding to surround a majority of the first shielding along the length of the cable.