Antenna Magnetic Shielding Sheet With Local Saturation Prevention

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Solution Overview

Problem

Magnetic field shielding sheets used in antenna modules are prone to magnetic saturation due to DC magnetic fields generated by alignment magnets, leading to performance degradation and increased module thickness when thicker sheets are used to mitigate this issue.

Innovation Solution

A magnetic field shielding sheet with a main shielding sheet made of magnetic material and a magnetic saturation-prevention member, which is stacked on one side to induce and block the DC magnetic field, preventing saturation while maintaining the same thickness as existing solutions. The saturation-prevention member has a larger cross-sectional area and is made of materials like amorphous or nano-crystalline alloys with a saturation magnetic flux density of 1.2 Tesla or more, and is optionally protected by films to prevent exposure and separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a magnetic field shielding sheet with increased thickness is used, then magnetic saturation due to DC magnetic field is prevented, but the overall thickness of the antenna module increases

Engineering Contradiction:

Improveprevention of magnetic saturationVSAvoidoverall thickness of antenna module

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The magnetic shielding sheet is segmented into multiple functional layers: a main shielding sheet for general magnetic field shielding and a separate magnetic saturation-prevention member specifically for handling DC magnetic fields from alignment magnets. This segmentation allows each layer to be optimized for its specific function, preventing magnetic saturation without requiring uniform thickness increase throughout the entire shielding structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The magnetic saturation-prevention member is positioned locally at specific locations where DC magnetic fields from alignment magnets are present. Rather than uniformly increasing the thickness of the entire shielding sheet, the saturation-prevention member is strategically placed only where needed to counteract the DC magnetic field, maintaining thin overall dimensions while providing targeted protection against magnetic saturation.

Inventive Principle:

Principle #3Local quality

2Productivity

If magnets are added for position alignment in wireless power transmission, then alignment efficiency is improved, but DC magnetic field causes magnetic saturation of the shielding sheet

Engineering Contradiction:

Improvealignment efficiencyVSAvoidperformance of antenna

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The magnetic saturation-prevention member acts as an intermediary element between the alignment magnets and the main shielding sheet. It intercepts and manages the DC magnetic field generated by the alignment magnets, preventing this field from reaching and saturating the main shielding sheet, thereby allowing both alignment functionality and antenna performance to coexist.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The DC magnetic field from alignment magnets, which initially causes harmful magnetic saturation, is converted into a beneficial effect by the magnetic saturation-prevention member. This member utilizes the DC magnetic field to induce magnetization in itself, creating a counteracting field that protects the main shielding sheet from saturation, thereby transforming the harmful DC field into a protective mechanism.

Inventive Principle:

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

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

Effectively prevents magnetic saturation of the main shielding sheet without increasing the overall thickness of the antenna module, ensuring efficient non-contact transmission and alignment while maintaining performance.

Implementation Method 1

at least one magnetic saturation-prevention member which is stacked on one side of the main shielding sheet so as to prevent magnetic saturation of the main shielding sheet by inducing a direct magnetic field generated from the magnet

Methodology Applied

Scientific EffectMagnetic induction: Electromagnetic Induction

Implementation Method 2

a main shielding sheet made of a magnetic material so as to shield a magnetic field generated from the antenna unit

Methodology Applied

Scientific EffectMagnetic shielding: Magnetic Field

Data Source

PatentUS12191565B2Magnetic shielding sheet for antenna module and antenna module including the same

Publication Date: 2025.01.07 AMOSENSE CO LTD

AI summary

Disclosed is an magnetic field shielding sheet for an antenna module is applied to an antenna module comprising an antenna unit operating in a predetermined frequency band and a magnet for position alignment, and comprises: a main shielding sheet made of a magnetic material so as to be able to shield a magnetic field generated from the antenna unit; and at least one magnetic saturation-prevention member stacked on one side of the main shielding sheet so as to be able to prevent magnetic saturation of the main shielding sheet by inducing a direct magnetic field generated from the magnet, wherein the magnetic saturation-prevention member is provided in a number corresponding to the number of magnets provided in the antenna module and is positioned on one side of the main shielding sheet so as to be positioned at a position corresponding to the magnets provided in the antenna module.