Wireless Power Transmitter EMI Reduction via Frequency Spreading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless power transfer technologies often cause electro-magnetic interference (EMI) in other electronic devices due to the high power transmission, which existing systems fail to effectively mitigate without reducing the overall transmission power.
Innovation Solution
A wireless power transmitter that varies the frequency of the power supply within a range below and above the resonance frequency, using a reference signal provider to adaptively spread the transmission power spectrum and reduce EMI by irregularly varying the frequency, thereby minimizing the deviation between maximum and minimum transmission power to less than 10 dB.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high power is transmitted for wireless power transfer, then power transmission capability is improved, but electro-magnetic interference (EMI) in other electronic devices increases
Solution Approach 1:
The patent applies dynamics by making the transmission frequency variable rather than fixed. The reference signal provider continuously adjusts the frequency of the reference signal, causing the transmission frequency to dynamically change over time. This dynamic frequency variation spreads the power spectrum across multiple frequencies, reducing EMI at any single frequency while maintaining high power transmission capability.
Solution Approach 2:
The patent changes the frequency parameter of the transmitted power signal. By varying the frequency around the resonance frequency (both below and above it), the system transforms the concentrated high-power signal into a spread spectrum signal. This parameter change reduces the power spectral density at any specific frequency, thereby reducing EMI while preserving overall transmission power.
2Object-generated harmful factors
If frequency is varied to reduce EMI, then electro-magnetic interference is reduced, but transmission power stability deteriorates
Solution Approach 1:
The patent implements feedback by continuously monitoring the power transmission status and adjusting the reference signal frequency accordingly. The system measures the actual transmission power and EMI levels, then uses this information to optimize the frequency variation pattern. This feedback mechanism ensures that power stability is maintained within acceptable ranges (deviation less than 10 dB) while achieving EMI reduction through frequency spreading.
Solution Approach 2:
The patent employs periodic action by varying the frequency in a controlled periodic manner around the resonance frequency. Instead of random frequency jumps, the system uses periodic modulation to spread the spectrum, which maintains predictable power transmission characteristics. The periodic frequency variation ensures that the transmitter operates systematically across different frequency points, balancing EMI reduction with power stability.
3Object-generated harmful factors
If frequency is spread below and above resonance frequency, then EMI is reduced through spectrum spreading, but system complexity increases
Solution Approach 1:
The patent achieves multi-functionality by designing the reference signal provider to simultaneously perform multiple tasks: generating the reference signal, varying the frequency to spread the spectrum, controlling the power stability, and reducing EMI. This single component handles what would otherwise require multiple separate subsystems, thereby reducing overall system complexity while achieving the desired EMI reduction through frequency spreading.
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 solution effectively reduces EMI by spreading the transmission power spectrum, decreasing harmonic components, and preventing interference in communications circuits and antennas without reducing the overall transmission power, thus enhancing the stability and efficiency of wireless power transfer.
Implementation Method 1
a transmitter configured to resonate the power amplified by the amplifier
Data Source
AI summary
A wireless power transmitter includes an amplifier configured to amplify a power; a transmitter configured to resonate the power amplified by the amplifier; and a reference signal provider configured to provide a reference signal to the amplifier and change a frequency of the reference signal.