Shared Coil Resonant Isolation for Wireless Charging and NFC

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Interference occurs between wireless charging and NFC/RFID signals in electronic devices due to different signal frequencies, affecting stability and user experience.

Innovation Solution

Incorporating resonant circuits between the wireless charging and NFC/RFID circuits and coils to prevent signal interference by matching resonance frequencies, using simple passive devices like inductors and capacitors to block unwanted signals, thereby reducing interference between circuits processing signals at different frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resonant circuits are added between wireless charging and NFC/RFID circuits, then signal interference is reduced, but device complexity increases

Engineering Contradiction:
Improvesignal stabilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces resonant circuits as intermediary components between the wireless charging circuit and NFC/RFID circuit. These resonant circuits act as frequency-selective mediators that allow desired signals to pass while blocking interfering signals at different frequencies, thereby resolving the technical contradiction by improving signal stability without requiring complete circuit isolation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the parameter of resonance frequency to differentiate and isolate signal paths. By designing resonant circuits with specific resonance frequencies matching either the wireless charging frequency or NFC/RFID frequency, the system dynamically changes the electrical characteristics of the circuit paths to allow or block specific signals, thus reducing interference while maintaining functional integration

Inventive Principle:
Principle #35Parameter changes

2Reliability

If resonant circuits are used to block unwanted signals, then interference is reduced, but manufacturing cost increases

Engineering Contradiction:
Improvesignal stabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs resonant circuits whose frequency-selective blocking capability is achieved through standard inductor and capacitor components with specific parameter values. By selecting commercially available components with appropriate inductance and capacitance values to achieve the desired resonance frequency, the solution reduces interference while avoiding custom-designed expensive components

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses passive resonant circuit components (inductors and capacitors) that are inexpensive, simple to manufacture, and readily available. These passive components replace more complex and expensive active filtering solutions, achieving signal isolation through passive frequency-selective blocking without requiring expensive active devices or complex control circuits

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

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 solution effectively reduces interference between wireless charging and NFC/RFID signals, enhancing the stability and user experience of electronic devices by preventing signal interference while maintaining cost-effectiveness and simplicity.

Implementation Method 1

A resonant circuit may be disposed between the first circuit and the coil, or between the second circuit and the coil... A resonant circuit disposed between the first circuit and the coil may be configured to prevent the second signal from passing

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4307518A1Electronic device for wireless power transfer
Publication Date: 2024.01.17 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4307518A1 patent drawingFigure 1
  • EP4307518A1 patent drawingFigure 2A
  • EP4307518A1 patent drawingFigure 2B

AI summary

This application provides an electronic device, including a first circuit, a second circuit, a coil, and one or more resonant circuits. The first circuit may transmit a first signal through the coil, and the second circuit may transmit a second signal through the coil. Frequencies of the first signal and the second signal are different. The resonant circuit may be disposed between the first circuit and the coil to prevent the second signal from passing, or disposed between the second circuit and the coil to prevent the first signal from passing, so as to prevent the first signal from interfering with the second circuit or prevent the second signal from interfering with the first circuit.