RFID Master Tag Conductive Coupling Shielded Tracking

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Solution Overview

Problem

Existing RFID systems face challenges in accurately tracking items within shielded boundaries due to the high cost and size of active RFID tags, confusion between items and IDs, and the need for manual access, which introduces errors and inefficiencies in inventory management.

Innovation Solution

A system utilizing a master tag operable in an RF field, connected to marker tags through conductive and inductive coupling, allowing for automatic and efficient reading of IDs from multiple tags without the need for direct access, using a wired connection system to facilitate communication between the master tag and marker tags.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If active RFID tags are used for tracking items in shielded boundaries, then tracking capability is improved, but cost and size increase

Engineering Contradiction:
Improvetracking capabilityVSAvoidsize and cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system divides the tracking function into two parts: passive RFID tags attached to items for identification, and an active master tag on the boundary for communication. This segmentation allows items to use low-cost passive tags while the boundary monitoring uses an active tag, resolving the contradiction between tracking reliability and cost/size.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The master tag acts as an intermediary between the RFID reader and the passive marker tags inside the shielded boundary. It receives RF energy from the reader, transmits it conductively to power and communicate with marker tags, and relays their IDs back to the reader, enabling tracking without requiring each item to have an expensive active tag.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If manual reading of serial numbers is used, then accessibility is improved, but error rate increases

Engineering Contradiction:
ImproveaccessibilityVSAvoidreading accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system enables automatic reading where the RFID reader and master tag automatically establish conductive coupling and read multiple marker tag IDs without human intervention. This eliminates manual reading errors while the system self-manages the complex task of penetrating shielded boundaries and reading multiple tags sequentially.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If RFID tags are placed in shielded boundaries, then item protection is improved, but reading capability deteriorates

Engineering Contradiction:
Improveshielding protectionVSAvoidreading capability
Core Design Contradiction:
Object-affected harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The master tag serves as an intermediary that bridges the shielded boundary. It receives RF energy from outside the boundary, converts it to conductive signals that can penetrate the shield, powers the internal marker tags, and transmits their IDs back through the conductive coupling to the external reader, thus maintaining reading capability while preserving shielding protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces direct electromagnetic coupling (which is blocked by shields) with conductive coupling through cables. This substitution allows energy and data to be transmitted through the physical cable medium that can penetrate or bypass the shielded boundary, overcoming the reading difficulty while maintaining protection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If multiple marker tags are read simultaneously, then inventory efficiency is improved, but confusion between items and IDs increases

Engineering Contradiction:
Improveinventory efficiencyVSAvoiditem-ID correspondence
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The system uses periodic time-slot based communication where the master tag sequentially activates and reads each marker tag in turn, with each tag responding in its designated time slot. This periodic action allows multiple tags to be read efficiently while maintaining clear item-ID correspondence through time-division multiplexing, preventing confusion.

Inventive Principle:
Principle #19Periodic action

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 accurate and efficient tracking of items within shielded areas by automatically reading and writing data to marker tags through a master tag, reducing errors and improving inventory management efficiency.

Implementation Method 1

a connection system for accessing one or more than one marker tag allocated to the one or more than one item, respectively, through conductive coupling

Methodology Applied
Scientific EffectConductive coupling: Conduction (electrical)

Implementation Method 2

The second antenna is inductively coupled with the first antenna, so that the tag module is readable through a combination of conductive and inductive coupling by the RFID reader

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Data Source

PatentEP1933260B1RFID based monitoring system and method
Publication Date: 2015.08.12 PSION INC
  • EP1933260B1 patent drawingFigure 1
  • EP1933260B1 patent drawingFigure 2
  • EP1933260B1 patent drawingFigure 3

AI summary

An RFID based monitoring system and method is provided. A tag module is allocated to an item to be traced, which is operable by an RFID reader. In the system, the tag module is accessed through conductive coupling with an entry point that is operable in an RF field of the RFID reader.