Open Ring Conductive Plate Support for Contactless IC
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Solution Overview
Problem
Contactless integrated circuit devices fail to operate effectively when mounted near conductive materials due to parasitic coil formation, which dissipates energy as heat, preventing communication and violating ISO/IEC standards, and existing shielding solutions are costly, fragile, or require special manufacturing.
Innovation Solution
A conductive plate support with an open ring shape and a central aperture that prevents parasitic inductive coupling by creating a discontinuity, allowing energy transfer to the coil antenna without altering the tuning frequency, made through machine milling or punching for economic and wide-scale application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional contactless IC with coil antenna is mounted near a conductive plate support, then the device can be positioned close to the conductive material, but parasitic eddy currents are induced in the conductive plate that oppose the RF field and damp the magnetic field, making communication impossible
Solution Approach 1:
The conductive plate support is segmented by introducing radial cuts that divide the continuous conductive surface into separate sectors. This segmentation prevents the formation of large-scale parasitic eddy currents by interrupting the current paths, thereby reducing electromagnetic interference while maintaining the benefit of mounting proximity to conductive materials
Solution Approach 2:
A non-conductive intermediate layer or patterned conductive structure is introduced between the coil antenna and the conductive plate support. This intermediary structure modifies the electromagnetic field distribution and prevents direct coupling that would induce harmful eddy currents, allowing the device to operate reliably near conductive materials
2Reliability
If magnetic shielding materials like ferrite or Mumetal are inserted between the coil antenna and conductive plate support to decouple them magnetically, then communication near conductive materials becomes possible, but the device becomes more expensive, fragile, and requires special manufacturing
Solution Approach 1:
The patent replaces expensive and fragile magnetic shielding materials with a cost-effective conductive plate support featuring radial cuts. This simplified structure achieves the same electromagnetic isolation function using inexpensive materials and standard manufacturing processes, eliminating the need for special handling and assembly
Solution Approach 2:
The invention changes the geometric parameters of the conductive plate support by introducing radial cuts at specific angles and positions. This parameter modification alters the electromagnetic field distribution and prevents parasitic coupling without requiring changes in material properties or complex manufacturing processes
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 reliable RF signal transmission between the read-write device and integrated circuit near conductive materials while maintaining compliance with ISO/IEC standards and ensuring the structural integrity and cost-effectiveness of the device.
Implementation Method 1
The contactless IC is powered by inductive coupling through the coil antenna by a read-write device used for receiving and transmitting a radio frequency from and towards the integrated circuit
Implementation Method 2
Due to Lentz's law, the magnetic flux through the plate induces eddy currents within the metal that oppose the field responsible for their creation, thus damping the magnetic field in the surface of the metallic or conductive plate
Data Source
AI summary
An electronic device includes an integrated circuit linked to a coil antenna forming at least a spiral having opposite ends connected to the integrated circuit, and a plate support for supporting the integrated circuit and the coil antenna. The plate support is conductive and open ring shaped, wherein the internal circumference of the ring is concentric to the spiral. The opening of the ring is obtained by a cut through the plate support. The coil antenna is fastened to and isolated from the plate support through an insulating material. The cut and the plate support are filled by the same insulating material.