RFID Device Ferrite Core Metal Interference Reduction
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Solution Overview
Problem
Conventional RFID devices on metal objects face challenges in reducing metal interference and enhancing electromagnetic induction capability, which affects the reception and transceiving of RFID tags.
Innovation Solution
The RFID device features a protective body with a printed circuit board, an induction coil antenna, and a ferrite core, where the induction coil is strategically positioned with a narrow gap to the protective body's surface and encased in insulating and plastic materials, enhancing electromagnetic induction capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the induction coil is positioned closer to the protective body surface, then electromagnetic induction capability is improved, but the risk of metal interference increases
Solution Approach 1:
The patent introduces a ferrite core as an intermediary material between the induction coil and the metal object. The ferrite core serves as a magnetic shield that directs and concentrates magnetic flux through the coil while blocking interference from metal objects. This mediator allows the coil to be positioned close to the metal surface without direct contact, thereby maintaining high induction capability while preventing metal interference.
Solution Approach 2:
The patent converts the harmful effect of metal proximity into a beneficial one by using the ferrite core to channel and concentrate magnetic flux. The metal object's presence, which would normally cause interference, is transformed into an opportunity to enhance magnetic coupling when properly mediated by the ferrite material, improving overall induction efficiency.
2Reliability
If the induction coil is positioned closer to the protective body surface, then transceiving capability is enhanced, but device complexity increases
Solution Approach 1:
The patent employs a nested structure where the induction coil is wound around the ferrite core, and both are integrated into a compact protective body. The PCB is positioned within the protective body, with the coil and core forming a nested assembly that maximizes space utilization. This nested arrangement achieves enhanced transceiving capability through close positioning while maintaining simple overall device structure.
Solution Approach 2:
The patent merges multiple functional elements into a single integrated assembly: the induction coil, ferrite core, PCB, and protective body are combined into one unified structure. The coil is directly mounted on the PCB, and the ferrite core is integrated with the coil assembly, eliminating the need for separate mounting components and reducing overall device complexity while achieving close positioning for enhanced transceiving.
3Reliability
If the induction coil is positioned closer to the protective body surface, then electromagnetic induction capability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements preliminary positioning features during manufacturing: the PCB includes pre-designed mounting pads and structural features that ensure precise positioning of the induction coil relative to the protective body. The ferrite core is pre-shaped with dimensions that automatically provide the optimal gap when assembled. These preliminary actions during manufacturing eliminate the need for complex post-assembly adjustments, achieving high induction capability without excessive positioning precision requirements.
Solution Approach 2:
The patent specifies optimal parameter ranges for the gap between the coil and protective body surface (less than or equal to 1 or 0.5 mm) rather than requiring exact dimensional precision. This parameter-based approach allows for normal manufacturing tolerances while maintaining effective electromagnetic induction capability, reducing the stringency of manufacturing precision requirements.
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 reduces metal interference, ensuring reliable RFID reader communication with the chip by improving the induction coil's capability to receive electromagnetic signals, minimizing reading failures on metal objects.
Implementation Method 1
enhance the electromagnetic induction capability or transceiving capability of the induction coil of the RFID device
Implementation Method 2
The RFID circuit unit comprises a ferrite core secured on the front surface of the PCB
Data Source
AI summary
The present invention disclosed a radio-frequency identification (RFID) device. The RFID device comprises a protective body and a RFID circuit unit located inside the protective body. The RFID circuit unit comprises a printed circuit board (PCB), a RFID chip and an antenna disposed thereon. A front surface of the PCB faces a top surface of the protective body; a rear surface of the PCB faces a bottom surface of the protective body.