Flexible PCB Spiral Antenna for Compact Wireless Charging
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Solution Overview
Problem
Conventional enameled-wire coils used in antennas for mobile devices face limitations in size reduction, leading to inefficient power transmission and reception due to increased thickness and non-uniform magnetic fields.
Innovation Solution
A flexible printed circuit board with a continuous spiral pattern and curved design that increases the coupling coefficient, allowing for a smaller size while maintaining efficient electricity transmission and reception, incorporating a magnetic layer to block unwanted magnetic fluxes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the antenna size is reduced, then the portability and integration are improved, but the inductance per unit area decreases and the magnetic field becomes non-uniform
Solution Approach 1:
The patent transitions from a planar coil structure to a three-dimensional spiral structure by curving the flexible printed circuit board. This dimensional change allows the coil to occupy vertical space, increasing the effective area for magnetic flux generation without increasing the footprint area, thereby maintaining high inductance in a compact form factor.
Solution Approach 2:
The patent applies curvature to the flexible printed circuit board to form a spiral-shaped coil. The curved configuration creates a more uniform magnetic field distribution compared to flat coils, and the spiral geometry increases the number of turns within a limited space, enhancing inductance while maintaining a small overall size.
2Reliability
If conventional enameled-wire coils are used, then the inductance can be increased, but the thickness must be increased reducing flexibility
Solution Approach 1:
The patent employs a flexible printed circuit board as the substrate for the coil, which is inherently thin and flexible. This replaces conventional thick enameled-wire winding structures. The FPCB allows the coil to achieve required inductance through its spiral geometry and multiple turns within a thin profile, maintaining flexibility and enabling integration into space-constrained and flexible device designs.
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 flexible printed circuit board enables efficient and compact antenna designs for wireless charging devices, enhancing transmission and reception efficiency while being suitable for wearable terminals.
Implementation Method 1
a magnetic flux generated by passing a current through the transmitting antenna is used to generate a current in the receiving antenna
Data Source
AI summary
A flexible printed circuit board according to an embodiment of the present invention includes at least one insulating layer having flexibility and containing a synthetic resin as a main component; and at least one conducting layer including a circuit pattern, wherein the circuit pattern includes a continuous spiral pattern, and the flexible printed circuit board includes a curved portion that curves such that one side and another side of the spiral pattern are disposed close to each other.