Electrical Cable Shielding for Signal Skew Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Shielded electrical cables experience signal timing skew due to air voids created where the cable shield overlaps, affecting the dielectric constant and impairing signal performance in high-speed data transmission applications.
Innovation Solution
The electrical cable design includes a conductive coating layer on the insulator with a seamless, direct metallization shield structure that positions the inner electrical shield within the air void, and a cable shield wrapped around the conductor assembly to form an outer shield, which covers any cracks or breaks in the coating layer, thereby maintaining uniform shield spacing and reducing skew.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a cable shield is wrapped around the conductor assembly, then electromagnetic shielding is provided, but air voids are created where the shield overlaps itself causing signal timing skew
Solution Approach 1:
An inner electrical shield (coating layer) is introduced as an intermediary between the conductors and the outer cable shield. This inner shield is positioned within the air void created by the overlapping cable shield, mediating the electromagnetic field distribution and eliminating the timing skew caused by the air void while maintaining the external shielding effectiveness.
Solution Approach 2:
The patent implements a nested shield structure where the inner electrical shield (coating layer) is embedded within the air void created by the outer cable shield overlap. This nested configuration allows the inner shield to correct the dielectric constant variation in the air void while the outer shield provides overall electromagnetic protection.
2Reliability
If the cable shield overlaps itself to form a continuous shield, then shielding coverage is improved, but the dielectric constant changes near conductors causing electrical signal timing skew
Solution Approach 1:
The inner electrical shield acts as a mediator that compensates for the dielectric constant changes introduced by the cable shield overlap. By positioning this inner shield within the air void, it restores uniform electromagnetic field distribution and eliminates timing skew while preserving the shielding coverage provided by the overlapping outer shield.
3Manufacturing precision
If a coating layer is applied to the insulator outer surface, then an inner electrical shield is formed, but cracks or breaks in the coating reduce shielding effectiveness
Solution Approach 1:
The patent applies local quality by having the outer cable shield provide enhanced coverage specifically at locations where the inner coating shield may have cracks or breaks. The overlapping flap structure ensures that areas with potential coating defects receive additional shielding coverage, compensating for local shield failures while maintaining overall shielding effectiveness.
Data Source
AI summary
An electrical cable includes a conductor assembly having a first conductor, a second conductor and an insulator surrounding the first conductor and the second conductor. The insulator has an outer surface and extends along a longitudinal axis for a length of the electrical cable. The conductor assembly has a coating layer on the outer surface of the insulator being conductive defining an inner electrical shield of the electrical cable. A cable shield is wrapped around the conductor assembly and has an inner edge and an outer edge. The outer edge is wrapped over the inner edge to form a flap covering the inner edge and extending along the longitudinal axis. The cable shield engages the inner electrical shield and forms an outer electrical shield exterior of the inner electrical shield.