Wireless Charging Pad NFC Antenna Array Coil Selection
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Solution Overview
Problem
Existing wireless charging systems require precise alignment between the receiver and charger coils for efficient energy transfer, which limits the flexibility of device placement and can result in suboptimal charging efficiency due to fixed positioning methods.
Innovation Solution
A method utilizing a pad with an array of charging coils and NFC antennas that measures and compares NFC field strengths to determine the optimal coil activation for charging, allowing for flexible device placement and dynamic adjustment during the charging process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fixed positioning methods are used to ensure coil alignment, then charging efficiency is improved, but device placement flexibility is reduced
Solution Approach 1:
The system dynamically adjusts which charging coils are activated based on the real-time detected position of the receiver device. Instead of using fixed positioning structures, the system continuously monitors NFC field strength at multiple antennas and selectively energizes appropriate coils to maintain optimal alignment regardless of device placement, thus achieving both high charging efficiency and placement flexibility
Solution Approach 2:
The system employs NFC field strength measurement as feedback to determine receiver position and adjust coil activation accordingly. By measuring field strength at multiple NFC antennas and comparing the values, the system identifies the receiver's location and activates the corresponding charging coils, creating a closed-loop control system that maintains optimal charging conditions while allowing free device placement
2Adaptability or versatility
If free-positioning with embedded charging coils is used, then device placement flexibility is improved, but charging efficiency may deteriorate due to improper coil selection
Solution Approach 1:
The system measures NFC field strength at multiple NFC antennas as feedback to identify the receiver's position. By comparing field strength values across different antennas, the system determines which charging coils should be activated to maintain optimal inductive coupling, ensuring high charging efficiency even with free device placement
Solution Approach 2:
The system replaces mechanical alignment mechanisms (such as physical guides or magnetic alignment features) with an electronic field-based detection and control system. NFC field strength measurements substitute for mechanical positioning, and electronic coil selection replaces mechanical alignment structures, enabling flexible placement while maintaining charging efficiency
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
Enables efficient and flexible wireless charging by ensuring optimal inductive coupling regardless of device position, improving charging efficiency and reducing charging time through dynamic coil selection and periodic position detection.
Implementation Method 1
causing the receiver to create an NFC field; measuring the NFC field strength at two or more NFC antennas in the pad
Implementation Method 2
Both the receiver and the pad typically have respective coils between which the energy for charging the receiver's battery is transferred via inductive coupling
Data Source
Figure 1
Figure 2~3
AI summary
An apparatus (pad) and method for wirelessly charging a receiver are disclosed. The pad includes one or more NFC antennas which can receive an NFC signal from the receiver. The pad also contains one or more charging coils. Measurement of the signal strength at each charging NFC antenna helps determine which charging coil(s) should be utilized to effect the most efficient charging of the receiver.