Resonant Antenna Coupling for Wireless Power Transfer Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power transfer technologies face inefficiencies due to radiation resistance and loss resistance, particularly in small, resonant antennas used in mobile devices, which often have narrow frequency bands and limited space for efficient energy transfer.
Innovation Solution
The use of resonant antennas that store energy in the near field for efficient power transfer between coils, optimizing mutual inductance and resistance values to maximize transfer efficiency and output power, with specific conditions for resonance, coupling, and resistance matching to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If small resonant antennas are used in mobile devices, then the antenna size is reduced to fit limited space, but the frequency band becomes narrow and transfer efficiency decreases
Solution Approach 1:
The patent applies parameter changes by adjusting the resonant frequency of both transmitting and receiving antennas to match, and by optimizing the quality factor (Q) of the antennas. This allows small antenna sizes while maintaining efficient power transfer within the narrowed frequency band through precise frequency and impedance matching parameters
2Length of stationary object
If energy is transmitted into free space as traveling electromagnetic waves, then power transfer distance is increased, but transfer efficiency decreases due to radiation resistance and loss resistance
Solution Approach 1:
The patent uses the near field magnetic coupling as an intermediary mechanism between transmitting and receiving antennas. Instead of direct far-field electromagnetic wave transmission, the system employs magnetic flux coupling in the near field, which reduces radiation losses and improves transfer efficiency while maintaining practical transmission distances suitable for mobile devices
3Volume of moving object
If small antenna size is used, then device compactness is improved, but radiation resistance and loss resistance increase reducing efficiency
Solution Approach 1:
The patent employs resonant oscillation at matched frequencies between transmitting and receiving antennas. This resonance effect amplifies the magnetic coupling between the small antennas, allowing them to overcome their inherently low radiation resistance and achieve efficient power transfer despite their small size and associated resistance losses
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 approach significantly increases transfer efficiency and output power by minimizing radiation and loss resistances, allowing for effective wireless power transfer within narrow frequency bands, even in constrained spaces like mobile devices.
Implementation Method 1
The use of resonant antennas that store energy in the near field for efficient power transfer between coils
Implementation Method 2
Antennas and their coupling characteristics for wireless power transfer via magnetic coupling
Data Source
AI summary
The disclosure provides systems, methods, and apparatus for wireless power transfer. In one aspect, an apparatus configured to receive wireless power from a transmitter is provided. The apparatus includes an inductor having an inductance value. The apparatus further includes a capacitor electrically connected to the inductor and having a capacitance value. The apparatus further includes an optimizing circuit configured to optimize transfer efficiency of power received wirelessly from the transmitter, provided that an amount of the power received wirelessly and provided to a load is greater than or equal to a received power threshold, or optimize the amount of the power received wirelessly from the transmitter, provided that the power transfer efficiency is greater than or equal to an efficiency threshold.