Figure-Eight Coil Antenna for Multi-Directional Near Field Coupling
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Solution Overview
Problem
Conventional NFC antenna configurations in thin portable devices are limited, restricting near field coupling capabilities to only the back side and failing to provide efficient multi-directional NFC and WPT functionality, which hampers user convenience and ergonomic usage scenarios.
Innovation Solution
Implementing a figure-eight coil antenna configuration with a continuous loop that includes an upper and lower loop of opposite rotation, wrapped around multiple surfaces, and optionally using a highly permeable flux guide like ferrite material to enhance magnetic flux guidance and coupling efficiency across various orientations, allowing near field coupling through multiple sides and angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional NFC antenna configuration is used in thin portable devices, then the device maintains a thin form factor, but the near field coupling capability is limited to only the back side
Solution Approach 1:
The antenna is divided into multiple segments including a first planar segment and a second planar segment that are spatially separated and oriented at different angles. Each segment can independently couple with external devices, enabling multi-directional near field coupling without requiring a single complex three-dimensional structure throughout the thin device body
Solution Approach 2:
The antenna transitions from a conventional single-plane configuration to a multi-planar configuration where segments are arranged in different spatial planes and orientations. This dimensional arrangement within the thin device profile enables coupling capabilities in multiple directions (front, back, sides) by utilizing the third dimension (depth/thickness) efficiently to position antenna segments at different orientations
2Ease of operation
If the antenna is configured for multi-directional coupling, then user convenience is improved, but the antenna structure becomes more complex
Solution Approach 1:
The antenna system is designed to perform multiple functions through its multi-planar segments, which can simultaneously or independently couple with devices placed on the front, back, or sides of the portable device. This universal coupling capability allows a single antenna structure to replace what would otherwise require multiple separate antennas or configurations, thereby improving user convenience without proportionally increasing overall system complexity
3Length of moving object
If flat coil antennas are used in thin devices, then the device maintains a thin form factor, but the aspect ratio becomes exaggerated
Solution Approach 1:
The antenna design utilizes multiple planes and orientations within the thin device profile, effectively using the depth dimension to create spatial separation between antenna segments. This allows the antenna to achieve multi-directional coupling capabilities without increasing the device's footprint area, thereby maintaining the thin form factor while reducing the need for exaggerated aspect ratios that would result from spreading a single large planar antenna across the device surface
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 enables efficient near field coupling through the front, top, bottom, or corner sides, improving user convenience by allowing NFC and WPT operations in various orientations, enhancing data transfer and power sharing capabilities while maintaining the device's thin form factor.
Implementation Method 1
Both near field coupling functions use radio frequency (RF) antennas in each of the devices to transmit and receive electromagnetic signals
Implementation Method 2
a highly permeable flux guide (e.g., ferrite material) may be placed between the coil antenna and the component to facilitate magnetic flux
Data Source
AI summary
Described herein are techniques related to near field coupling and wireless power transfers. A portable device may include a coil antenna that includes an upper loop and a lower loop to form a figure-eight arrangement. The figure-eight coil antenna arrangement is wrapped against top and bottom surfaces of a component to establish near field coupling through front side, top side, bottom side, or corner side of the portable device. Further, a flux guide may be placed between the coil antenna and the component to facilitate magnetic flux at the upper loop and the lower loop to induce current of the same phase during receive mode. During transmit mode, the flux guide facilitates the magnetic flux at the upper loop and the lower loop to generate magnetic fields of the same direction.