Metal-Mount RFID Tag Structure for Stable UHF Communication
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Solution Overview
Problem
Conventional RFID tags with a magnetic sheet sandwiched between the tag and metal attachment objects may fail in the UHF band due to insufficient thickness of the magnetic sheet, leading to communication failures.
Innovation Solution
An RFID tag configuration that includes an inlay with an IC chip, a loop conductor, and an antenna unit, along with a magnetic sheet laminated on the attachment object side and a spacer layer between the magnetic sheet and the attachment object, to enhance communication performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnetic sheet is sandwiched between an RFID tag and metal to enable communication, then communication capability is improved, but if the magnetic sheet thickness is small, communication fails in the UHF band
Solution Approach 1:
A spacer layer is introduced as an intermediary element between the magnetic sheet and the metal attachment object. This spacer layer mediates the interaction between the magnetic sheet and metal, allowing the magnetic sheet to maintain sufficient thickness for UHF band communication while still being attached to the metal surface. The spacer prevents direct contact that would cause eddy current losses while maintaining the magnetic shielding effect.
Solution Approach 2:
The invention changes the thickness parameter of the magnetic sheet to be sufficiently large (not small) to enable UHF band communication. By adjusting this critical dimension parameter and combining it with the spacer layer, the system achieves reliable communication in the UHF band while attached to metal surfaces.
2Adaptability or versatility
If metal is present near the RFID tag, then the tag can be attached to metal surfaces, but electromagnetic waves are dissipated as eddy currents and energy cannot be efficiently obtained
Solution Approach 1:
The spacer layer serves as a mediator that separates the magnetic sheet from the metal attachment object. This intermediary structure prevents the formation of eddy currents in the metal by eliminating direct electromagnetic coupling between the antenna and metal, while still allowing the RFID tag to be mechanically attached to metal surfaces. Energy efficiency is restored by preventing parasitic eddy current losses.
3Reliability
If a magnetic sheet is used to enable communication on metal, then electromagnetic waves can circulate through the magnetic sheet, but the configuration becomes more complex
Solution Approach 1:
The RFID tag structure is segmented into distinct functional layers: the inlay layer (containing antenna and IC chip), the magnetic sheet layer (for electromagnetic wave circulation), and the spacer layer (for separation from metal). This segmentation allows each layer to perform its specific function optimally while maintaining overall system reliability for communication on metal surfaces.
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 proposed configuration improves communication performance by allowing electromagnetic waves to circulate through the magnetic sheet, efficiently supplying energy to the IC chip, and reducing the influence of metal attachment objects on communication.
Implementation Method 1
Sandwiching the magnetic sheet between a RFID tag and metal to which the RFID tag is attached allows electromagnetic waves received by an antenna to circulate through the magnetic sheet and energy to be efficiently supplied to an IC chip
Implementation Method 2
If metal is present near the RFID tag, electromagnetic waves sent from a reader/writer, which transmits/receives data, to the RFID tag may be dissipated as eddy currents in the metal
Data Source
AI summary
A radio frequency identification (RFID) tag includes an inlay; a magnetic sheet laminated on an attachment object side of the inlay; and a spacer layer disposed between the magnetic sheet and the attachment object. The inlay includes an IC chip configured to store identification information, a loop conductor connected to the IC chip, and an antenna unit connected to the loop conductor.