Shielded Cable Foil Shorting for High-Frequency Impedance Matching
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Solution Overview
Problem
High-frequency signal transmission in shielded cables is hindered by undesired electromagnetic wave feeding into the shielding foil, causing impedance mismatch, reflections, and signal energy loss due to the two-conductor system of the shielding foil.
Innovation Solution
A prefabricated cable design with a shielding foil and mesh, where the metallic coatings on the outer and inner lateral surfaces are electrically connected via conductive means, such as via, clamping elements, or material displacement, to short-circuit the two-conductor system at the plug-side end, preventing electromagnetic wave feeding into the shielding foil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the shielding foil is formed with metallic coatings on both lateral surfaces, then shielding effectiveness is improved, but signal energy loss increases due to undesired transmission paths
Solution Approach 1:
The patent removes the harmful capacitive coupling effect by extracting the dielectric material from between the metallic coatings at the end region of the shielding foil. This eliminates the undesired transmission path while preserving the shielding functionality, as the metallic coatings are no longer capacitively coupled when the dielectric is removed.
Solution Approach 2:
Instead of using the dielectric material to enhance shielding (its intended function), the patent inverts its effect by removing it to eliminate the harmful capacitive coupling. This inversion transforms the dielectric from a shielding-enhancing element into a signal-loss-reducing element by preventing the formation of an unwanted transmission path.
2Object-affected harmful factors
If the shielding foil structure is used, then shielding performance is improved, but impedance matching deteriorates causing reflections
Solution Approach 1:
The patent extracts the dielectric material from the end region of the shielding foil to eliminate the capacitive coupling that causes impedance mismatch. This removal prevents the formation of an unwanted two-conductor system that would otherwise create impedance discontinuities and signal reflections.
3Stability of the object's composition
If the two-conductor system of the shielding foil is intact, then shielding continuity is maintained, but resonant effects increase causing additional signal loss
Solution Approach 1:
The patent removes the dielectric material from the end region to break the continuous two-conductor system formed by the metallic coatings. This extraction eliminates the resonant cavity effect while maintaining shielding continuity through alternative means, preventing resonant frequency enhancements that would cause additional signal loss.
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
This design maintains impedance matching, reduces signal reflections, and minimizes signal loss by preventing parasitic guidance of electromagnetic waves, thereby enhancing transmission efficiency.
Implementation Method 1
the metallic coating on the outer lateral surface is electrically conductively connected to the metallic coating on the inner lateral surface of the shielding foil via at least one electrically conductive connection
Data Source
AI summary
The present invention relates to a prefabricated cable, to a cable plug connector arrangement, and to an electrical plug connection. A prefabricated cable (1) has a shielding foil (4), a shielding braid (5) which surrounds the shielding foil (4), and a cable sheath (6) which surrounds the shielding braid (5). The shielding braid (5) is exposed from the cable sheath (6) at a plug-side end (8) of the prefabricated cable (1). The shielding foil (4) has a dielectric foil (9) made of a dielectric material, and a metal coating (101, 102) on an outer lateral surface and on an inner lateral surface of the dielectric foil (9). The metal coating (101) on the outer lateral surface is electrically conductively connected to the metal coating (102) on the inner lateral surface in a plug-side end region (11) of the shielding foil (4) via at least one electrically conductive connection (12). According to the invention, the at least one electrical connection (12) is passed through the dielectric foil (9) in a plug-side axial end region of the shielding foil (4) and/or at least partially covers an end face of the dielectric foil (9) at a plug-side axial end of the shielding foil (4).