Symmetrical Filter Arrangement for Vehicle NFC Interference

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Solution Overview

Problem

Existing contactless data transmission devices for vehicles face challenges with complex and expensive filtering circuits, which often suffer from mutual interference between coils, requiring costly solutions like magnetically shielded coils or increased spacing.

Innovation Solution

A device for contactless data transmission using a processing means with a matching circuit that employs symmetrical filter arrangements with functionally identical elements arranged differently to reduce mutual interference, allowing for efficient and space-saving filtering, and enabling reliable near-field communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If filtering circuits are used to improve signal quality, then receiving and transmitting functionality is improved, but device complexity and cost increase

Engineering Contradiction:
Improvereceiving and transmitting functionalityVSAvoidfiltering circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple filtering functions into a single integrated filter circuit that processes signals for both receiving and transmitting operations. This merging approach maintains signal quality while reducing the overall complexity compared to separate filtering circuits for each function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The filter circuit is designed to serve multiple purposes: filtering received signals, preparing transmitted signals, and operating in different modes (receiving and transmitting) using the same hardware components. This multi-functionality reduces device complexity while maintaining reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Object-generated harmful factors

If magnetically shielded coils or increased spacing are used to reduce interference, then filtering effectiveness is improved, but cost and space requirements increase

Engineering Contradiction:
Improvemutual interference between coilsVSAvoidspace requirements
Core Design Contradiction:
Object-generated harmful factorsVSArea of stationary object

Solution Approach 1:

The patent employs asymmetrical winding directions for adjacent coils in the filter circuit. By winding coils in opposite directions (e.g., clockwise and counter-clockwise), the magnetic fields generated by adjacent coils naturally oppose each other, reducing mutual interference without requiring increased spacing or magnetic shielding.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent converts the potentially harmful magnetic interference between adjacent coils into a beneficial effect by using opposing winding directions. The interference is transformed into a canceling effect where the magnetic fields neutralize each other, reducing overall interference without additional space or shielding materials.

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

3Reliability

If complex filtering circuits are used, then signal quality is improved, but manufacturing cost increases

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

Solution Approach 1:

The patent achieves effective filtering by optimizing key parameters of simple circuit elements (inductance values, capacitance values, winding directions) rather than using complex circuit topologies. This parameter optimization maintains signal quality while using standard, easily manufactured components.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The filter circuit uses standard, off-the-shelf electronic components (resistors, capacitors, inductors) that are inexpensive and easily replaced. The design avoids custom-made complex filters, opting instead for assemblies of common components that reduce manufacturing cost while maintaining adequate signal quality.

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

The solution effectively reduces interference and space requirements, enabling reliable contactless data transmission while optimizing signal filtering for near-field communication, thus improving the efficiency and cost-effectiveness of vehicle authentication systems.

Implementation Method 1

A communication participant can thus generate a high-frequency carrier signal to cause the emission of, in particular, high-frequency alternating magnetic fields via an antenna

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

when using NFC (Near Field Communication) as a communication technology for data transmission, communication between the participants can be achieved through electromagnetic induction using loosely coupled coils

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3544197B1Device for contactless data transmission
Publication Date: 2020.12.16 HUF HÜLSBECK & FÜRST GMBH & CO KG
  • EP3544197B1 patent drawingFigure 1
  • EP3544197B1 patent drawingFigure 2
  • EP3544197B1 patent drawingFigure 3

AI summary

The invention relates to a device (10) for contactless data transmission, preferably for NFC communication, preferably for a vehicle (1), comprising: - at least one processing means (50), - at least one connection arrangement (70) for connection to an antenna for data transmission, wherein the connection arrangement (70) is electrically connected to the processing means (50) via at least two opposing transmission paths (15, 16), - an adaptation circuit (20) at least for providing filtering for these transmission paths (15, 16), wherein a filter arrangement (20.1, 20.2) of the adaptation circuit (20) is integrated in each of the transmission paths (15, 16) in order to provide the filtering in a uniform manner for the transmission paths (15, 16) by means of the filter arrangements (20.1, 20.2).2) according to a first sub-arrangement, have several functionally identical elements (21) symmetrically to each other, and according to a second sub-arrangement, have at least two functionally identical filter elements (41, 42) which are designed differently from the symmetry of the first sub-arrangement.