RJ45 Jack Dielectric Film Layout for Crosstalk Compensation

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Solution Overview

Problem

Existing network jack designs face challenges in effectively canceling crosstalk while maintaining economical manufacturing costs, as previous methods using flexible circuit boards or crossovers in contact traces are either costly or inefficient in achieving desired coupling.

Innovation Solution

The design incorporates a thin dielectric film between layers of plug interface contacts (PICs) to achieve capacitive coupling, allowing for closer proximity and enhanced crosstalk compensation near the plug/jack contact point, using capacitive plates and crush ribs to maintain precise coupling and reduce manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flexible printed circuit board is used to move compensation circuitry close to plug interface contacts, then crosstalk compensation effectiveness is improved, but manufacturing cost increases

Engineering Contradiction:
Improvecrosstalk compensation effectivenessVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive flexible printed circuit boards with a simple dielectric film structure that can be manufactured more economically. The dielectric film serves the same functional purpose of enabling close proximity compensation contacts without requiring the complex flexible circuit board construction, thereby reducing manufacturing costs while maintaining compensation effectiveness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the structural parameters by moving from a flexible circuit board architecture to a dielectric film-based architecture. This parameter change allows the compensation contacts to achieve the necessary proximity for effective crosstalk compensation while using a simpler, more cost-effective manufacturing approach.

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If crossover is implemented in contact traces near mandrel, then compensation begins closer to plug jack mating interface, but sufficient coupling is difficult to obtain

Engineering Contradiction:
Improvedistance from mating interfaceVSAvoidcoupling effectiveness
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent transitions from planar trace crossovers to a three-dimensional stacked configuration using dielectric films. This dimensional change allows compensation contacts to be positioned in close proximity both laterally and vertically, achieving sufficient coupling effectiveness while maintaining close distance from the mating interface that was not possible with two-dimensional trace crossovers alone.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a nested structure where compensation contacts are positioned in alternating layers separated by dielectric films. This nesting arrangement allows the compensation signals to be generated in close proximity to the mating interface while maintaining the necessary coupling between traces through the layered configuration.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If PICs are positioned in close proximity for higher coupling, then crosstalk compensation is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecrosstalk compensation effectivenessVSAvoidpositioning precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent uses thin dielectric films to separate and position the PIC layers. These thin films provide a standardized, manufacturable spacing mechanism that achieves the necessary close proximity for effective coupling while using conventional manufacturing tolerances. The dielectric film acts as a precision spacer that is easier to manufacture than requiring direct metal-to-metal positioning precision.

Inventive Principle:
Principle #30Flexible shells and thin films

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 approach effectively moves crosstalk compensation closer to the plug/jack interface, reducing the need for additional compensation further along the data path and maintaining specified electrical performance while being cost-effective.

Implementation Method 1

a dielectric film positioned between at least some of the first sections of the first plurality of PICs and at least some of the first sections of the second plurality of PICs

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

a thin dielectric film between two layers of PICs that provide crosstalk compensation by way of their geometry. Compensation is achieved by way of capacitor plates which sandwich a thin dielectric film

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP3443621B1Communication jack having a dielectric film between plug interface contacts
Publication Date: 2024.02.28 PANDUIT CORP
  • EP3443621B1 patent drawingFigure 1
  • EP3443621B1 patent drawingFigure 2
  • EP3443621B1 patent drawingFigure 3

AI summary

Embodiments of the present invention relate to designs for network jacks which can be used for cable connectivity. In an embodiment, the present invention is an RJ45 jack that utilizes a thin dielectric film between two layers of PICs that provide crosstalk compensation by way of their geometry. Compensation is achieved by way of capacitor plates which sandwich a thin dielectric film. This allows for the layers of PICs to be in close proximity and achieve higher coupling where desired, allowing a greater amount of compensation to occur close to the plug/jack contact point. This can have the effect of moving compensation closer to the plug/jack contact point, which in turn may reduce the amount of compensation needed further along the data path.