Spiral RF Antenna Layout for Orientation-Independent Card Coupling
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Solution Overview
Problem
Current radio frequency chip carriers in smart cards have limited communication range and require specific orientation for effective coupling with proximity readers, restricting their usability.
Innovation Solution
A method for manufacturing a radio frequency antenna in the form of a spiral on a flat substrate with the axis parallel to the plane, using conductive wire and alternating portions to ensure electromagnetic coupling in multiple orientations, allowing for improved communication range and orientation independence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional planar antenna is used on a smart card, then the manufacturing is simple and cost-effective, but the field of action is limited and requires specific orientation for effective coupling
Solution Approach 1:
The patent applies dimensionality change by transitioning from a conventional two-dimensional planar antenna to a three-dimensional spiral antenna structure. The spiral configuration with its axis substantially in the plane of the substrate creates a more complex spatial arrangement that enables omnidirectional electromagnetic field generation, allowing effective coupling regardless of the card's orientation relative to the reader.
2Adaptability or versatility
If the antenna axis is perpendicular to the substrate plane, then the coupling is optimized for a specific orientation, but the field of action is restricted when the card is not properly oriented
Solution Approach 1:
The patent employs asymmetry by positioning the spiral antenna's axis substantially in the plane of the substrate rather than perpendicular to it. This asymmetric orientation relative to the substrate surface creates an omnidirectional radiation pattern that maintains reliable electromagnetic coupling across multiple card orientations, eliminating the need for precise alignment between the card and reader.
3Adaptability or versatility
If a spiral antenna with axis in the plane of the substrate is manufactured, then orientation independence is achieved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the spiral antenna structure into multiple discrete turns or segments that are sequentially connected. This segmented approach simplifies the manufacturing process, allowing the spiral pattern to be created through repeated deposition or etching cycles rather than requiring a single complex continuous pattern, thereby reducing manufacturing complexity while maintaining the orientation-independent functionality.
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
The solution enables efficient and cost-effective radio frequency communication in various orientations, enhancing the performance and usability of radio frequency transponders by maintaining effective coupling with radio frequency readers regardless of the card's orientation.
Implementation Method 1
A method for manufacturing a radio frequency antenna in the form of a spiral on a flat substrate with the axis parallel to the plane, using conductive wire and alternating portions to ensure electromagnetic coupling in multiple orientations
Data Source
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Figure 5~8
AI summary
The invention relates to a method for manufacturing an antenna (13) for a radiofrequency transponder, said antenna including a spiral comprising turns (S1- S4) which extend, at least in part, over an insulating substrate (12); the method is characterised in that it includes the step according to which at least one first portion (13i) of each turn (S1-S4) is deposited on said substrate (12) at a first plane level P1, at least one second portion 13b of each turn being formed or kept at a distance (e) from the first plane level (P1) of the substrate, the axis (SX) of the spiral being parallel to the plane (P1) of the substrate. The invention also relates to a portable electronic object comprising, in a fixed or removable manner, the obtained antenna.