RFID Power Control via Iterative Floor Ceiling Detection

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Solution Overview

Problem

Existing RFID printers face challenges in consistently programming individual RFID tags without inadvertently reading or writing to nearby tags, due to varying tag sensitivities and the need for precise power level control.

Innovation Solution

The method involves setting an initial read power level and iteratively adjusting it to determine the floor and ceiling read power levels, allowing for the configuration of optimal read and write power levels for individual RFID tags while isolating the supply roll.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If low write power levels are used to prevent accidental configuration of multiple tags, then nearby tags are protected from unintended programming, but programming consistency of the intended tag deteriorates

Engineering Contradiction:
Improveprevention of accidental tag configurationVSAvoidprogramming consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts the write power level based on the detected read power level and determined power margin. Instead of using a fixed low power level, the write power is optimized in real-time for each tag type and configuration, ensuring consistent programming while maintaining protection against accidental writes through controlled power thresholds.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the power level parameter dynamically by determining a floor read power level and calculating an optimal write power level that is a specific amount above this floor. This parameter adjustment ensures reliable programming while maintaining a safety margin to prevent accidental configuration of nearby tags.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If high write power levels are used to ensure consistent programming, then programming consistency improves, but accidental reading or writing of nearby tags increases

Engineering Contradiction:
Improveprogramming consistencyVSAvoidaccidental tag reading/writing
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The system uses feedback from iterative interrogation at decreasing power levels to determine the floor read power level. This feedback mechanism allows the system to identify the precise power threshold where tag response ceases, enabling setting of an optimal write power level that is a controlled amount above this threshold, thus ensuring consistent programming without excessive power that could affect nearby tags.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary determination of the floor read power level and optimal write power level before actual tag programming. This preliminary action includes iterative testing and calculation to establish safe and effective power levels, ensuring that when programming occurs, the power settings are already optimized to prevent harmful effects on nearby tags.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If different write power levels are used for different RFID tag types, then programming consistency for each tag type improves, but system complexity increases

Engineering Contradiction:
Improveprogramming consistency per tag typeVSAvoidpower level management
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system performs self-service by automatically determining the optimal write power level for each tag type through iterative interrogation and analysis of the floor read power level. Instead of requiring manual configuration for each tag type, the system autonomously calculates and sets the appropriate power levels, reducing complexity while maintaining programming consistency across different tag types.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system dynamically changes the write power level parameter based on detected tag characteristics and determined power margins. Rather than maintaining fixed power levels for different tag types, the system adjusts the power parameter in real-time based on measured responses, simplifying the management of multiple tag types through a unified adaptive approach.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If iterative power level determination is performed, then optimal power settings are achieved, but processing time increases

Engineering Contradiction:
Improvepower level optimizationVSAvoidpower determination time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system uses periodic action by performing iterative interrogation at decreasing power levels in a structured sequence to efficiently determine the floor read power level. This periodic approach systematically explores the power threshold with controlled steps, achieving optimal power settings while minimizing unnecessary iterations and processing time.

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

This approach ensures that only the intended RFID tag is targeted, preventing accidental configuration of nearby tags, and achieving consistent programming across different types of RFID tags.

Implementation Method 1

RFID tags typically receive power from nearby radio frequency sources, such as an RFID reader or RFID printer that is transmitting radio frequency energy at the resonant frequency of the RFID tag

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

an RF attenuator configured to attenuate the RF signal

Methodology Applied
Scientific EffectAttenuation: Absorption (EM radiation)

Data Source

PatentEP4018357B1RFID read and write power setting system and method
Publication Date: 2025.04.30 AVERY DENNISON RETAIL INFORMATION SERVICES LLC
  • EP4018357B1 patent drawingFigure 1
  • EP4018357B1 patent drawingFigure 2
  • EP4018357B1 patent drawingFigure 3

AI summary

A system and method for configuring Radio Frequency Identification (RFID) read and write power levels includes an RFID module that generates RF signals, a digital step attenuator that attenuates RF signals, an antenna that transmits attenuated RF signals, and an RF shield that isolates the antenna from an RFID label supply roll. A floor read power is determined by iteratively interrogating an RFID label while decreasing the RF signal power until the label fails to respond to the interrogation. A ceiling read power is determined by iteratively interrogating the RFID label while increasing the RF signal power until multiple labels respond to the interrogation. The read power level is set between the floor read power and the ceiling read power. The write power level is determined by iteratively attempting to program the RFID module while increasing the write power from the read power level until successfully written.