RFID Antenna Loop Configuration for Focused Magnetic Field
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing RFID tag issuing devices face challenges in selectively writing information to a target RFID tag without affecting adjacent non-target tags, due to the difficulty in generating a focused magnetic field.
Innovation Solution
The antenna design includes loop portions arranged in a specific configuration with power supply and termination resistor connections on a substrate, along with conductive portions forming L- and U-shapes, to create a concentrated magnetic field along the longitudinal direction, ensuring targeted communication with RFID tags.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional antenna is used to write information to RFID tags, then information can be written to tags, but the magnetic field spreads to adjacent non-target tags causing unintended writing
Solution Approach 1:
The antenna is divided into multiple independent loop portions (first through fourth loop portions) arranged in parallel. Each loop portion can be independently controlled to generate magnetic field segments that collectively form a focused magnetic field region, allowing precise targeting of specific RFID tags while minimizing spread to adjacent tags.
Solution Approach 2:
Different loop portions are configured with specific orientations and connections (series/parallel combinations) to create localized magnetic field intensification at targeted positions. The asymmetric connection arrangement ensures that the magnetic field concentration is directed toward specific tag positions rather than uniformly distributed, achieving local quality enhancement at target zones while reducing field strength in non-target areas.
2Adaptability or versatility
If the label sheet is displaced during conveyance, then the target position of the RFID tag changes, but conventional antennas cannot adapt to maintain focused magnetic field
Solution Approach 1:
The antenna system provides dynamic adaptability through its multiple loop portions that can be selectively activated and configured. When sheet displacement is detected or anticipated, the control system can dynamically reconfigure which loop portions are active and how they are connected (series or parallel), thereby dynamically adjusting the magnetic field focus position to track the displaced tag location and maintain writing precision.
3Manufacturing precision
If multiple loop portions are used to improve field concentration, then targeted writing improves, but antenna structure becomes more complex
Solution Approach 1:
Multiple loop portions are merged into a unified antenna structure sharing common substrates and conductive patterns. The loop portions are interconnected through shared conductive paths and control lines, allowing them to function as an integrated system rather than separate components. This merging approach achieves focused magnetic field generation through cooperative operation of multiple loops while minimizing the increase in structural complexity compared to using a single large antenna.
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 configuration allows for reliable and precise data writing to RFID tags on a label sheet, even when the sheet is displaced, by generating a strong and focused magnetic field that intersects the conveyance direction, thereby preventing interference with non-target tags.
Implementation Method 1
The antenna design includes loop portions arranged in a specific configuration with power supply and termination resistor connections on a substrate, along with conductive portions forming L- and U-shapes, to create a concentrated magnetic field along the longitudinal direction, ensuring targeted communication with RFID tags.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An antenna includes a power supply point on a substrate, a termination resistor on the substrate, and first and second lines connecting the power supply point and the termination resistor. The first line is disposed on a first surface of the substrate. The second line is disposed on a second surface of the substrate. The first line includes a plurality of loop portions arranged along a longitudinal direction of the substrate and separated from each other. The second line includes a plurality of relay portions connecting the power supply point to one of the loop portions closest thereto, connecting adjacent pairs of the loop portions to each other, and connecting the termination resistor and one of the loop portions closest thereto.