Antenna Device Angular Stability via Asymmetric Coil Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing antenna devices for RFID systems experience degradation in communication performance due to varying angles with the reader/writer, leading to unreliable communication when the mobile terminal is positioned at different angles relative to the reader/writer.
Innovation Solution
An antenna device with a plate-shaped magnetic core and a coil conductor wound around it, where the first and second conductor portions are positioned to avoid overlap, and the magnetic core can be made of a sheet-shaped mixture of magnetic powder and resin or sintered magnetic pieces, with optional thicker or bent portions to enhance magnetic flux and coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional antenna device is used, then the structure is simple, but communication performance degrades when the angle with the reader/writer varies
Solution Approach 1:
The coil conductor is divided into multiple segments (first conductor portion, second conductor portion, third conductor portion) arranged at different positions and orientations. This segmentation allows each segment to effectively couple with magnetic flux from different directions, maintaining communication performance stability across varying angles while keeping the overall structure manageable.
Solution Approach 2:
Different conductor portions are positioned with different orientations and spacings relative to the magnetic core. The first conductor portion is positioned closer to one end of the flat conductor, while the second conductor portion is positioned closer to the other end, creating local variations in coupling characteristics that collectively improve angular stability.
2Length of moving object
If the coil conductor is wound tightly around the magnetic core, then the coupling is strong, but the communication distance is limited
Solution Approach 1:
The coil conductor is configured to extend in multiple directions rather than being wound tightly in a single plane. The first and second conductor portions are arranged at different positions relative to the magnetic core, creating a three-dimensional coupling structure that extends the effective communication range while maintaining adequate coupling strength through distributed magnetic flux interception.
3Adaptability or versatility
If the antenna device is positioned at various angles relative to the reader/writer, then the adaptability is improved, but the magnetic fluxes cancel each other out
Solution Approach 1:
The coil conductor is configured with asymmetric positioning of its segments relative to the magnetic core. The first conductor portion is positioned closer to one end of the flat conductor, while the second conductor portion is positioned closer to the other end, creating an asymmetric arrangement that prevents magnetic flux cancellation across different angles and improves angular adaptability.
Solution Approach 2:
The multi-segment coil conductor configuration dynamically adapts to different angular positions by having different segments become more or less effective depending on the orientation. This dynamic characteristic allows the antenna to maintain reliable communication performance across a wide range of angles without requiring active adjustment mechanisms.
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 maintains stable communication performance over a wider range of angles (0° to 90° or more) by ensuring magnetic fluxes do not cancel each other out, thereby extending the maximum communication distance and improving overall communication reliability.
Implementation Method 1
antenna device for use in RFID (radio frequency identification) systems, which communicate with external devices using electromagnetic signals
Implementation Method 2
a plate-shaped magnetic core having first and second main surfaces and a coil conductor wound around the magnetic core
Data Source
AI summary
This disclosure provides an antenna device including an antenna coil having a plate-shaped magnetic core with first and second main surfaces and a coil conductor wound around the magnetic core, and a flat conductor adjacent to the antenna coil. For instance, the flat conductor can be a ground electrode formed on or within a circuit substrate. The coil conductor includes a first conductor portion adjacent to the first main surface of the magnetic core and a second conductor portion adjacent to a second main surface thereof. The first conductor portion of the antenna coil is closer to an end portion of the flat conductor than the second conductor portion, with the second main surface of the magnetic core facing the flat conductor.