Multi-layered RFID Coupler for Selective Transponder Communication
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Solution Overview
Problem
RFID systems face challenges in selectively communicating with a targeted transponder among multiple adjacent transponders, leading to errors and increased complexity, cost, and difficulty in determining the physical location of the transponder, especially in printer-encoder applications where transponders are closely spaced.
Innovation Solution
A near field coupler with a grounded terminal load, coupling element, and impedance matching element is used, structured in a parallel stacked arrangement with dielectric layers and ground planes, to match the transponder's antenna impedance and reduce power loss, allowing selective communication without anti-collision management techniques or physical isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple passive transponders are placed within range of the RF transceiver's antenna, then the system can handle bulk media processing, but read/write errors increase due to simultaneous activation of multiple transponders
Solution Approach 1:
The patent divides the electromagnetic field interaction into selective segments by using the coupler's directional radiation pattern and impedance matching to target specific transponders. The coupler structure creates distinct near-field zones that can be selectively activated, allowing the system to process multiple transponders in bulk while maintaining individual addressability and reducing simultaneous activation conflicts.
2Reliability
If transponders are dispersed along media units with sufficient spacing, then read/write errors are reduced, but media material costs increase and packaging volume increases
Solution Approach 1:
The patent applies local quality by creating a localized electromagnetic environment through the coupler structure that provides selective energy concentration. The impedance matching element and grounded terminal load create a controlled near-field zone that delivers targeted electromagnetic energy to specific transponder locations without requiring increased spacing between them on the media units.
3Reliability
If transponders are widely dispersed by providing longer labels or increased spacing, then read/write errors are reduced, but printer-encoder throughput slows down
Solution Approach 1:
The patent implements preliminary action by pre-configuring the coupler's impedance matching characteristics before transponder interrogation. The impedance matching element is designed to optimally couple with transponders at specific predetermined positions, allowing the system to rapidly select and activate target transponders without requiring slow sequential scanning or increased physical spacing, thus maintaining high throughput while ensuring accurate communication.
4Productivity
If anti-collision management techniques are used to manage multiple transponders, then simultaneous reading and writing is enabled, but system complexity increases and response time increases
Solution Approach 1:
The patent extracts the collision management function from the software/control domain and implements it through the physical coupler structure's electromagnetic field characteristics. The coupler's directional radiation pattern and impedance matching properties physically isolate and select target transponders, eliminating the need for complex anti-collision algorithms and reducing system complexity while enabling simultaneous multi-transponder communication.
5Reliability
If electromagnetic isolation of specific transponders is achieved using RF-shielded housings or anechoic chambers, then targeted communication is possible, but system cost increases and space requirements increase
Solution Approach 1:
The patent transitions from three-dimensional physical shielding (housings and chambers) to a two-dimensional planar coupler structure with layered construction. The coupler uses stacked conductive and dielectric layers to create directional electromagnetic field confinement in the near-field zone, achieving targeted transponder communication without requiring bulky three-dimensional shielding structures.
6Loss of energy
If a conventional quarter wavelength transmission line is used for impedance matching, then power loss is reduced, but the coupler length increases making it unsuitable for space-restricted systems
Solution Approach 1:
The patent nests the impedance matching function within a compact layered structure where conductive and dielectric layers are stacked concentrically. This nested arrangement allows the electromagnetic fields to interact in a confined volume, achieving impedance matching and power transfer efficiency without requiring the extended linear length of conventional quarter-wavelength transmission lines.
7Volume of stationary object
If standard length media rolls are used with closely spaced transponders, then packaging volume is reduced, but selective communication with individual transponders becomes difficult
Solution Approach 1:
The patent replaces mechanical positioning and physical separation methods with electromagnetic field-based selection through the coupler's impedance matching characteristics. The coupler's designed radiation pattern and near-field coupling properties enable electronic identification and selective activation of transponders based on their electromagnetic response, eliminating the need for mechanical spacing or complex physical location determination systems.
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 efficient and cost-effective selective communication with a targeted transponder, reducing power consumption and system complexity, while maintaining high accuracy and adaptability to different transponder types and shapes without the need for additional shielding or complex anti-collision methods.
Implementation Method 1
The coupling element is configured to couple to the transponder and transmit an electromagnetic signal to the transponder
Implementation Method 2
The impedance matching element is configured to match the wave impedance of the coupling element to an input impedance of the transceiver
Implementation Method 3
The coupling element and the impedance matching element are disposed in a parallel stacked arrangement and separated by at least one dielectric layer and at least one ground plane
Data Source
AI summary
A RFID coupler capable of selectively communicating with a targeted transponder from among a group of multiple adjacent transponders. The coupler includes a grounded terminal load, a coupling element, a connecting element, an impedance matching element, and an input terminal. The coupling element is connected with the grounded terminal load and is configured to couple with the transponder by emanating an electromagnetic field. The input terminal is connected to a transceiver for receiving communication signals. The impedance matching element is connected to the input terminal and is configured to substantially match an input impedance of the coupler to a source impedance of the transceiver. The connecting element connects the impedance matching element to the coupling element. The coupling element and the impedance matching element are substantially parallel and separated by at least one dielectric layer and at least one ground plane.