RFID Tag Coil Layout to Minimize Antenna Coupling
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Solution Overview
Problem
Existing RFID tags face complications due to unnecessary coupling between the antenna and the coils in the impedance matching circuit, which hinders independent design of the RFIC module and antenna, making the overall RFID tag design complex.
Innovation Solution
The RFID tag incorporates an impedance matching circuit with coils where the main planes of the magnetic flux loops generated by the antenna and the coils are orthogonal, minimizing unnecessary coupling by aligning the magnetic flux planes differently for the antenna and the coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the impedance matching circuit uses coils arranged on the antenna base material, then the RFIC module can be mounted on the antenna, but unnecessary coupling between the coils and antenna occurs
Solution Approach 1:
The patent applies asymmetry by making the main plane of the magnetic flux loop generated in the coil non-parallel to the main plane of the magnetic flux loop generated by the antenna. This angular relationship creates an asymmetric configuration that minimizes unnecessary coupling between the impedance matching circuit coils and the antenna, while still allowing both components to coexist on the same base material.
2Reliability
If the coils in the impedance matching circuit are arranged to match impedance, then impedance matching is achieved, but the design of the entire RFID tag becomes complicated
Solution Approach 1:
The patent applies segmentation by separating the design considerations into independent modules: the antenna design can be optimized independently, and the impedance matching circuit with its non-parallel coil arrangement can be designed separately. This modular approach maintains impedance matching reliability while reducing overall design complexity, as each component can be designed and adjusted independently without affecting the other.
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 enhances the independence between the RFIC module and the antenna, simplifying the RFID tag design and reducing unwanted coupling, thereby improving performance.
Implementation Method 1
a magnetic flux loop generated in the vicinity of the coil by the antenna
Data Source
AI summary
An RFID tag is provided that includes an insulator film, an antenna with an antenna conductor pattern disposed on the insulator film, and an RFIC module mounted on the insulator film. The RFIC module includes an RFIC and an impedance matching circuit. The impedance matching circuit includes a first coil and a second coil. Main planes of magnetic flux loops generated in the vicinities of the first coil and the second coil by the antenna are not parallel to main planes of magnetic flux loops generated in the first coil and the second coil.