Ferrule Cable Termination for Foil Shielded Impedance Cables
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Controlled impedance cables with conductive foil shields lack structural integrity, making it difficult to attach SMA connectors reliably due to the thin and flexible nature of the foil wraps, which affects mechanical contact and signal integrity.
Innovation Solution
The development of a cable termination system that includes a separate or integrated ferrule embodiment, providing rigidity and strain relief by clamping a rigid ferrule over the foil shield, allowing for precise alignment and attachment of SMA connectors, and ensuring electrical contact and phase length control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If foil wrap shield is used in controlled impedance cable, then manufacturing cost is reduced and flexibility is improved, but structural integrity deteriorates making SMA connector attachment difficult
Solution Approach 1:
A ferrule is introduced as an intermediary component between the foil shield and the SMA connector. The ferrule provides the necessary structural support and rigidity for connector attachment, while the foil shield maintains its cost-effective and flexible properties. The ferrule acts as a mediator that transfers mechanical loads from the connector to the cable assembly without requiring the foil shield to bear these loads directly.
Solution Approach 2:
The cable assembly becomes a composite structure combining the foil shield, dielectric material, and ferrule. This composite construction leverages the advantages of each material: the foil shield provides flexibility and cost-effectiveness, the dielectric provides electrical insulation and impedance control, and the ferrule provides structural integrity for connector attachment.
2Adaptability or versatility
If foil wrap shield is used in controlled impedance cable, then cable flexibility is improved, but mechanical contact reliability deteriorates
Solution Approach 1:
The ferrule serves as a mediator that ensures reliable mechanical contact between the SMA connector and the cable assembly. It provides a rigid mounting surface for the connector while allowing the foil shield to remain flexible. The ferrule's internal structure is designed to maintain consistent electrical and mechanical contact regardless of the foil shield's flexibility.
3Volume of stationary object
If foil wrap shield is used in controlled impedance cable, then cable density is improved, but strain relief capability deteriorates
Solution Approach 1:
The cable assembly is segmented into distinct functional zones: the foil shield provides dense shielding and EMI protection, the dielectric provides electrical insulation, and the ferrule provides structural support and strain relief. This segmentation allows each component to optimize its specific function without compromising overall performance.
Solution Approach 2:
The ferrule acts as a mediator that absorbs and distributes mechanical strain away from the foil shield connection points. It provides a robust interface for the SMA connector while allowing the dense, flexible foil shield to maintain its volume-efficient structure.
Data Source
AI summary
A cable termination that enables the attachment of SMA connectors to controlled-impedance cables with a conductive foil wrap shield; for the separate ferrule embodiment, the sheath is stripped back on the cable, exposing the foil shield surrounding the dielectric; a ferrule is slid or clamped over the foil shield and bonded; the face of the ferrule is dressed so that the foil shield and dielectric are flush with the ferrule face and the signal conductor protrudes from the face this cable subassembly is installed in the boss of a housing that prevents movement of the ferrules relative to each other and so that each ferrule face is aligned with an opening in the boss through which an SMA connector barrel is attached to the ferrule a cover secures the cable subassembly in the housing.