Magnetic Induction Antenna with Concave-Convex Loop for Railway Balise

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Solution Overview

Problem

Existing magnetic induction antenna systems face challenges in maximizing the contact volume for efficient data transfer at high speeds without damaging the tag or exceeding practical antenna size limitations, particularly in railway applications.

Innovation Solution

The magnetic induction antenna arrangement features a conducting loop with a second antenna that partially cancels the electromagnetic field produced by the first antenna, optimizing the magnetic flux distribution to maintain a consistent field strength over a larger contact volume, achieved through concave and convex sections in the loop design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If the activation power (electric current through the magnetic induction antenna) is increased to increase the contact volume, then the tag can be powered at greater distances and read for longer durations, but the maximum acceptable power limit is exceeded which may destroy the tag

Engineering Contradiction:
Improvecontact volumeVSAvoidtag damage from excessive power
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The antenna arrangement uses concave and convex sections to create non-uniform current distribution along the loop, concentrating the electromagnetic field in specific regions rather than uniformly across the entire loop. This allows the contact volume to be extended in critical areas without proportionally increasing the total power, thereby preventing tag damage while maintaining adequate power transfer.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent optimizes the antenna geometry to dynamically adapt the field distribution as the train passes over the balise. The concave and convex sections create a field pattern that maintains consistent power transfer over a longer distance and time period, allowing high-speed reading without requiring excessive peak power that would damage the tag.

Inventive Principle:
Principle #15Dynamics

2Volume of stationary object

If the size of the antenna arrangement is increased to improve the contact volume, then the reading distance and time are extended, but the antenna cannot fit under the train and mounting height constraints are violated

Engineering Contradiction:
Improvecontact volumeVSAvoidantenna arrangement size
Core Design Contradiction:
Volume of stationary objectVSVolume of moving object

Solution Approach 1:

Instead of uniformly increasing the antenna size, the patent introduces concave and convex sections that locally modify the current distribution and field pattern. This allows the contact volume to be effectively increased through strategic field concentration rather than physical expansion, maintaining compact antenna dimensions that fit under the train.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameters of the antenna loop by introducing concave and convex sections, which fundamentally alter the electromagnetic field distribution. This parameter modification allows the same physical antenna size to produce an extended and optimized contact volume, overcoming the size constraint while maintaining compact dimensions.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If simple conductive loop forms are used, then the device complexity is low, but large magnetic induction antennas are required to read balises at high speed

Engineering Contradiction:
Improveantenna structure complexityVSAvoidantenna size
Core Design Contradiction:
Device complexityVSVolume of stationary object

Solution Approach 1:

The patent maintains the simplicity of a conductive loop structure but introduces localized geometric modifications (concave and convex sections) that dramatically improve the field distribution. This approach preserves low device complexity while achieving the extended contact volume needed for high-speed reading, avoiding the need for large antenna dimensions.

Inventive Principle:
Principle #3Local quality

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 design enhances the contact volume, allowing reliable data transmission at high speeds while preventing tag damage and reducing signal dynamic range, leading to improved accuracy and reduced interference from nearby cables.

Implementation Method 1

magnetic induction antenna arrangement used for contact-free information transfer systems using magnetic coupling

Methodology Applied
Scientific EffectMagnetic induction: Electromagnetic Induction

Data Source

PatentEP2527225B1Magnetic induction antenna arrangement
Publication Date: 2016.04.27 BOMBARDIER TRANSPORTATION GMBH
  • EP2527225B1 patent drawingFigure 1~2
  • EP2527225B1 patent drawingFigure 3

AI summary

The invention relates to a magnetic induction antenna arrangement comprising an electrically conducting loop (1) forming a first antenna (2) for powering tags over the entire range from high to low distances between the first antenna (2) and the tag by producing a first electromagnetic field. The conducting loop (1) or a second conducting loop forms at least one second antenna (3), which is arranged in such a manner that a second electromagnetic field produced by the second antenna (3) partially cancels the first electromagnetic field produced by the first antenna (2).