Surface Wave Wireless Power Transfer for Long-Range Coupling

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Solution Overview

Problem

Existing near-field wireless power transfer systems suffer from electromagnetic energy attenuation and alignment issues, particularly at low frequencies, limiting their effectiveness over long distances and requiring precise positioning.

Innovation Solution

A system utilizing an electromagnetic field confinement device, such as a waveguide, to generate and propagate electromagnetic energy in surface wave mode, allowing energy transfer over long distances with controlled coupling independent of distance, using waveguides filled with dielectric materials or metamaterials to minimize radiation and decay.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If conventional near-field wireless power transfer systems are used, then power transfer is achieved, but electromagnetic energy attenuation occurs due to radiation and undesired leaks, limiting transfer distance

Engineering Contradiction:
Improvetransfer distanceVSAvoidelectromagnetic energy attenuation
Core Design Contradiction:
Length of stationary objectVSLoss of energy

Solution Approach 1:

The patent introduces surface waves as an intermediary mechanism for power transfer. Instead of direct electromagnetic radiation between transmitter and receiver, the system uses surface waves guided along a structure (such as a waveguide or transmission line) to carry energy over long distances with minimal radiation loss. The surface wave mode confines the electromagnetic energy to the surface of the guiding structure, preventing undesired leaks and enabling long-distance transfer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the propagation mode parameter from conventional radiating electromagnetic waves to surface wave mode. By operating in surface wave mode, the system achieves different propagation characteristics including reduced attenuation and extended range. The surface wave mode is excited by specific transmitter-receiver coupling configurations that convert conventional electromagnetic energy into guided surface waves.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If low-frequency systems are used for wireless power transfer, then power transfer is achieved, but alignment between transmitter and receiver becomes critical, requiring very specific positioning and short coupling distance

Engineering Contradiction:
Improvealignment toleranceVSAvoidcoupling distance
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The surface wave guiding structure acts as an intermediary that decouples the alignment requirements from the distance between transmitter and receiver. The surface waves are guided along the structure rather than requiring direct line-of-sight coupling, allowing the transmitter and receiver to be positioned at different locations along the guide without strict alignment requirements. This intermediary guidance mechanism enables long coupling distances while maintaining ease of operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If conventional electromagnetic radiation is used for power transfer, then energy is transmitted, but radiation losses and undesired leaks occur, limiting system efficiency

Engineering Contradiction:
Improveradiation lossVSAvoidtransfer distance
Core Design Contradiction:
Loss of energyVSLength of stationary object

Solution Approach 1:

The patent converts the potentially harmful radiation losses into beneficial guided surface wave propagation. By designing the system to excite surface wave modes rather than conventional radiating modes, the electromagnetic energy that would otherwise be lost to radiation is instead confined to the guiding structure and transmitted efficiently over long distances. The surface wave mode transforms radiation loss into useful guided energy transfer.

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

Enables wireless power transfer over extended distances with controlled coupling, facilitating ease of alignment and enabling charging of devices, including moving vehicles, without radiation or significant attenuation, and supporting high power levels.

Implementation Method 1

the emitter comprises an electromagnetic field confinement device configured to operate in the surface wave mode for generating and propagating the electromagnetic energy in the form of surface waves

Methodology Applied
Scientific EffectSurface wave mode: Surface Acoustic Wave

Implementation Method 2

the waveguide is filled with a dielectric material

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP4629478A1A system for near-field wireless power transfer
Publication Date: 2025.10.08 UNIVERSITAT AUTONOMA DE BARCELONA
  • EP4629478A1 patent drawingFigure 1~2
  • EP4629478A1 patent drawingFigure 3~5
  • EP4629478A1 patent drawingFigure 6~8(b)

AI summary

The present invention relates to a system for near-field wireless power transfer, comprising an emitter (1) for generating electromagnetic energy, from at least one input electrical power signal injected therein, and propagating the electromagnetic energy therethrough, to be wirelessly captured in the near field by a receiver (2), wherein the emitter (1) comprises an electromagnetic field confinement device configured to operate in the surface wave mode for generating and propagating the electromagnetic energy in the form of surface waves.