Planar Three-Axis Antenna With Foil Cores For Thin IC Cards
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional three-axis antennas are too thick to be incorporated into thin articles like IC cards, despite providing omni-directional reception sensitivity.
Innovation Solution
A three-axis antenna design featuring planar coils with foil-type cores arranged in parallel, allowing for orthogonal maximum reception sensitivity directions, which reduces thickness and enables integration into thin articles by adjusting the shape and relative permeability of the foil cores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If three antenna coils are arranged with orthogonal winding axes around a bar-type core, then omni-directional reception sensitivity is achieved, but the antenna thickness exceeds 3 mm making it unsuitable for thin articles like IC cards
Solution Approach 1:
The patent transitions from a three-dimensional bar-type core structure to a two-dimensional planar configuration. The antenna coils are arranged in the same plane rather than being wound around a vertical bar, effectively changing the dimensional approach to achieve both thinness and omni-directional sensitivity.
Solution Approach 2:
The patent changes the physical parameters of the core material by using ferrite sheets with specific thickness (0.2-0.5 mm) and relative permeability values (100-500). This parameter optimization allows the antenna to maintain omni-directional reception sensitivity while reducing overall thickness to under 3 mm.
2Length of stationary object
If the antenna thickness is reduced to fit thin articles, then it can be incorporated into IC cards, but the reception sensitivity may be compromised
Solution Approach 1:
The patent uses composite construction with ferrite sheets combined with coil windings. The ferrite material provides magnetic flux concentration and enhancement, compensating for the reduced thickness. The specific ferrite composition and thickness are optimized to maintain reception sensitivity while achieving the required thin profile for IC card integration.
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 design achieves omni-directional reception sensitivity while being significantly thinner than conventional antennas, making it suitable for incorporation into IC cards and other thin devices.
Implementation Method 1
a foil-type core inserted in the aperture of said coil
Implementation Method 2
an antenna coil comprising a planar coil which is wound around a winding axis in a circumferential direction and has an aperture
Data Source
AI summary
A three-axis antenna having a first to a third antenna coils arranged so that directions of the maximum reception sensitivities are orthogonal to each other, the first to the third antenna coils comprising respectively: a planar coil being wound around the winding axis in circumferential direction and has an aperture; and a foil-type core inserted in the aperture; the foil-type core being arranged a plane to be in parallel to the plane of the first to the third coils.