Wireless Power Transfer System Using Near-Field Coupling
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Solution Overview
Problem
Current wireless charging technologies face challenges such as limited distance and accuracy in power transfer, inability to adjust power levels for different devices, and inefficiency due to fixed radiated power, which restricts the types of devices that can be charged and wastes energy as batteries near full charge.
Innovation Solution
A wireless power transfer system using near-field coupling between loop antennas, where the transmitter and receiver are configured for mutual resonance, allowing adjustable power delivery based on device usage and charging history, enabling efficient energy transfer over larger distances with adaptive charging profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If plane wave radiation coupling is used between transmit and receive antennas, then wireless power transmission can be achieved, but power coupling efficiency drops quickly with distance
Solution Approach 1:
The patent changes the fundamental parameter of electromagnetic wave propagation from plane wave (far-field) to evanescent wave (near-field) coupling. This enables power transfer at distances of several feet to several meters while maintaining high coupling efficiency by utilizing the exponentially decaying but non-radiating electromagnetic fields in the near-field region, avoiding the inverse-square law losses of far-field radiation.
2Device complexity
If fixed radiated power level is used in wireless charging system, then system simplicity is maintained, but power levels cannot be adjusted for different devices and battery states
Solution Approach 1:
The patent implements dynamic power adjustment by continuously monitoring battery charge state and device power requirements, then adapting the transmitted power level accordingly. The system transitions from static fixed power to dynamic variable power, allowing optimal charging rates that extend battery life while accommodating different device types and charging stages.
Solution Approach 2:
The patent incorporates feedback mechanisms where the receiving device communicates battery status and power requirements back to the transmitting device. This enables closed-loop control where transmitted power is continuously adjusted based on real-time battery state, preventing overcharging and optimizing charging efficiency for different device types.
3Speed
If rapid charging profile is used to meet user needs, then charging speed is improved, but battery life is reduced
Solution Approach 1:
The patent implements periodic or staged charging profiles that alternate between high-power and low-power charging phases. Instead of continuous rapid charging, the system uses variable rate charging that adapts to battery state, employing higher rates when beneficial and lower rates when battery health is at risk, thereby extending overall battery lifespan while maintaining acceptable charging speed.
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 system achieves efficient energy transfer with adjustable power levels, extending battery life by optimizing charging profiles based on usage patterns, reducing waste, and accommodating various devices, while maintaining charging efficiency and convenience.
Implementation Method 1
A wireless power transfer system using near-field coupling between loop antennas
Implementation Method 2
where the transmitter and receiver are configured for mutual resonance
Data Source
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Figure 6A
AI summary
Exemplary charging device includes a processor and charging current for coupling to a battery. In an exemplary embodiment, the processor defines charging profiles for charging the battery at different charge rates. A profile can be selected based on a determinable time event and may be modified based on a charging history. Adjustable charging power is supplied to the battery at a power level, a charging duration, or a combination thereof based on the selected profile. A wireless power transmitter can also define charging profiles and charging histories for receivers that receive power from the transmitter based on an identifier from the receiver. The transmitter can select the charging profile based on a determinable time event and may be modified based on a charging history. The transmitter supplies power through the wireless power link at a power level, a charging duration, or a combination thereof based on the selected profile.