Comb-structured shielding layer for wireless charging EMI

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Solution Overview

Problem

Wireless charging transmitters in vehicles generate electromagnetic interference (EMI) through E-fields that exceed OEM compliance standards, potentially causing safety issues and interfering with other in-vehicle electronics, while traditional shielding methods can hinder magnetic induction charging.

Innovation Solution

A wireless charging transmitter equipped with a comb-structured shielding layer that allows magnetic H-field radiation to pass through while shielding E-field radiation, ensuring compliance with EMC and EMI standards by separating the shielding areas electrically connected to a reference potential.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a simple metal shielding sheet is used to block E-field radiation, then E-field shielding is improved, but magnetic H-field transmission is blocked preventing wireless charging

Engineering Contradiction:
ImproveE-field radiation interferenceVSAvoidwireless charging function
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The shielding layer is segmented into multiple comb-shaped conductive strips separated by non-conductive spaces, rather than using a continuous metal sheet. This segmentation allows magnetic field lines to pass through the gaps while the conductive strips provide E-field shielding, resolving the contradiction between E-field blocking and H-field transmission.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the shielding structure have different properties: the comb-shaped conductive strips provide E-field shielding while the non-conductive spaces between them allow magnetic field penetration. This local differentiation of shielding properties enables selective blocking of E-fields while maintaining H-field transmission for wireless charging.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If wireless charging transmitters are added to vehicles, then convenience of electronic device charging is improved, but E-field radiation exceeds EMC and EMI compliance standards

Engineering Contradiction:
Improvewireless charging convenienceVSAvoidE-field radiation
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The invention converts the harmful E-field radiation into a controlled structure by using comb-shaped conductive strips that guide and contain the electric fields within the metal portions, while the gaps allow magnetic field passage. This transforms the harmful radiation into a structured field distribution that complies with EMC and EMI standards while maintaining wireless charging functionality.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Adaptability or versatility

If wireless communicating devices are added step by step to vehicles, then functionality is improved, but electromagnetic interference with other electronic components increases

Engineering Contradiction:
Improveelectronic device functionalityVSAvoidelectromagnetic interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The shielding structure parameters (comb tooth width, spacing, height, and orientation) are optimized to provide effective E-field shielding while maintaining magnetic field transmission. By adjusting these geometric parameters, the shielding layer can be tuned to block harmful E-field radiation across different frequency ranges while allowing wireless charging operation, thus enabling increased electronic device functionality without excessive EMI.

Inventive Principle:
Principle #35Parameter changes

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 comb-structured shielding layer effectively reduces E-field radiation below predetermined thresholds, allowing safe and compliant wireless charging of electronic devices while maintaining magnetic induction coupling, thus preventing interference with other vehicle electronics.

Implementation Method 1

The wireless charging technology in general charges the electronic devices by magnetic induction caused by quick alternating currents in the transmitter coils of the wireless charging transmitter (or module)

Methodology Applied
Scientific EffectMagnetic induction: Electromagnetic Induction

Implementation Method 2

the comb-structured shielding layer is configured to allow the magnetic H-field electromagnetic radiations pass through the at least one comb-structured shielding layer

Methodology Applied
Scientific EffectElectromagnetic field shielding: Faraday Cage

Data Source

PatentEP2648309B1Comb-structured shielding layer and wireless charging transmitter thereof
Publication Date: 2019.04.17 NOVERO DABENDORF
  • EP2648309B1 patent drawingFigure 1
  • EP2648309B1 patent drawingFigure 2
  • EP2648309B1 patent drawingFigure 3

AI summary

A comb-structured shielding layer and a wireless charging transmitter thereof are provided. The wireless charging module is connected to a power source, has at least one wireless charging coil and at least one comb-structured shielding layer, and is configured to convert alternative current power from the power source to H-field electromagnetic radiations, and wirelessly charges an electronic device. The comb-structured shielding layer is disposed between the wireless charging module and the target electronic device and configured to allow the H-field electromagnetic radiations pass through. The comb-structured shielding layer includes a first area and a second area. The first area is electrically connected to a reference electric potential. The second area is electrically connected to the reference electric potential through the first area, and is configured to shield the E-field electromagnetic radiations but allow the H-field electromagnetic radiations pass through the comb-structured shielding layer.