RFID Tag Mode Transition for Read Range and Power

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Solution Overview

Problem

Existing RFID systems face challenges in achieving a long read range while maintaining low size, cost, and response time, particularly in inventory solutions that require numerous tags, fast response times, and high accuracy, which is not effectively addressed by passive RFID tags and Battery Assisted Passive (BAP) RFID tags that increase size, cost, and complexity.

Innovation Solution

The implementation of a method for operating an RFID tag that monitors RF energy levels, transitions operational modes based on threshold values, and uses a rechargeable power source to enable communication with a tag reader, incorporating features like time slotted communication and motion-based receiver control to optimize power usage and reduce infrastructure costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If passive RFID tags are used, then size and cost are reduced, but read range and response time are insufficient

Engineering Contradiction:
Improvetag sizeVSAvoidread range
Core Design Contradiction:
Volume of moving objectVSLength of stationary object

Solution Approach 1:

The tag dynamically transitions between sleep mode and active communication mode based on detected RF energy levels. The receiver is selectively enabled when RF energy exceeds a threshold, allowing the tag to achieve long read range when needed while maintaining small size and low power consumption during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the tag by adjusting the receiver enablement threshold based on the number of communication collisions. When collisions are detected, the threshold is adjusted to optimize the balance between read range and power consumption, enabling the tag to adapt to different environmental conditions.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If BAP RFID tags are used, then read range is increased, but size, cost and complexity increase

Engineering Contradiction:
Improveread rangeVSAvoidtag complexity
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

Instead of continuously operating the receiver and power source as in BAP tags, the system uses periodic activation based on RF energy detection. The tag remains in a low-power state and only activates communication functions when RF energy from a reader exceeds the threshold, significantly reducing complexity and power requirements while maintaining effective read range.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The tag autonomously determines when to activate its receiver based on detected RF energy levels, eliminating the need for external battery management circuitry and complex power control systems. The tag self-regulates its operational state based on environmental RF conditions, reducing overall system complexity.

Inventive Principle:
Principle #25Self-service

3Reliability

If the receiver is continuously enabled, then communication reliability is improved, but power consumption increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses feedback from RF energy level detection to control receiver enablement. The tag continuously monitors RF energy and uses this feedback to dynamically adjust its operational state, enabling the receiver only when sufficient energy is detected to ensure reliable communication while minimizing power consumption during low-activity periods.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The receiver transitions dynamically between enabled and disabled states based on real-time RF energy conditions. This dynamic operation ensures the receiver is active only when communication is likely to succeed, maintaining reliability while dramatically reducing average power consumption compared to continuous operation.

Inventive Principle:
Principle #15Dynamics

4Length of stationary object

If the threshold value is lowered, then read range is extended, but false activations increase

Engineering Contradiction:
Improveread rangeVSAvoidactivation accuracy
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The system performs preliminary detection of RF energy levels before activating the receiver. By monitoring RF energy continuously in a low-power state and comparing it against the threshold, the tag prepares for activation only when conditions are favorable, extending effective read range while avoiding false activations from background RF noise.

Inventive Principle:
Principle #10Preliminary 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 solution enhances read range, reduces infrastructure costs, and ensures efficient and accurate inventory management by enabling tags to communicate effectively with a remote reader while minimizing battery drain and infrastructure needs, allowing for 100% tag readability in facilities.

Implementation Method 1

monitoring a level of Radio Frequency (RF) energy being received by the first RFID tag

Methodology Applied
Scientific EffectElectromagnetic field detection: Electromagnetic Induction

Implementation Method 2

uses a rechargeable power source to enable communication with a tag reader

Methodology Applied
Scientific EffectElectrical energy storage: Electrical Accumulator

Data Source

PatentEP3695345B1Systems and methods for operating tag
Publication Date: 2023.02.15 TYCO FIRE & SECURITY GMBH
  • EP3695345B1 patent drawingFigure 1
  • EP3695345B1 patent drawingFigure 2
  • EP3695345B1 patent drawingFigure 3

AI summary

Systems and methods for operating a Radio Frequency Identification ("RFID") tag. The methods comprise: monitoring a level of Radio Frequency ("RF") energy being received by the RFID tag; performing operations by a circuit of the RFID tag to compare the level of RF energy in a given frequency band to a first threshold value; and transitioning an operational mode of the RFID tag from a first operational mode in which a receiver is disabled to a second operational mode in which the receiver is enabled, when the level of RF energy exceeds the first threshold value. The RFID tag is able to communicate with a remote tag reader when the RFID tag is in the second operational mode and not when the RFID tag is in the first operational mode.