Wireless Power Feeding System Resonance Modulation for Signal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power feeding systems face challenges in maintaining reliable signal transmission due to fluctuations in the position of the receiver, magnetic coupling strength, load power consumption, and input voltage, which affect the amplitude and phase of the resonant voltage, making simple keying schemes unreliable.
Innovation Solution
A wireless power feeding system with a transmitter and receiver that includes a resonant circuit, a resonance modulation circuit to vary input impedance, and a demodulator circuit to detect and demodulate signals based on the establishment of an electromagnetic resonance condition, allowing for stable signal transmission regardless of the transmitter and receiver state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If simple ASK or PSK schemes are used for signal transmission, then the device complexity is reduced, but the reliability of signal transmission deteriorates due to fluctuations in resonant voltage characteristics
Solution Approach 1:
The patent changes the parameter being modulated from amplitude or phase (which are affected by resonant voltage fluctuations) to the resonant frequency itself. By using frequency shift keying (FSK) where the receiver varies its resonant frequency to encode binary data, the system achieves reliable signal transmission because frequency detection is less sensitive to amplitude and phase variations caused by coupling strength changes, load variations, and input voltage fluctuations.
2Reliability
If the system attempts to compensate for all fluctuating characteristics (coupling strength, load state, input voltage) to maintain reliable signal transmission, then the reliability improves, but the device complexity increases significantly
Solution Approach 1:
The patent extracts and eliminates the problematic dependencies on amplitude and phase characteristics from the signal transmission mechanism. By using only frequency variation for modulation, the system removes the need for complex compensation mechanisms for coupling strength, load state, and input voltage fluctuations. The transmitter simply detects frequency variations without needing to know or compensate for the underlying causes of resonant voltage fluctuations.
3Adaptability or versatility
If the receiver position relative to the transmitter varies, then the adaptability of the system increases, but the signal transmission reliability deteriorates due to changes in magnetic coupling strength
Solution Approach 1:
The patent makes the system dynamically adaptive by using frequency-based modulation that automatically compensates for coupling variations. As the receiver position changes and coupling strength varies, the resonant frequency detection method naturally adapts because it relies on detecting the frequency at which maximum current flows, regardless of the absolute coupling strength. This allows the system to maintain reliable communication across a wide range of positions without requiring active position tracking or coupling compensation.
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 highly stable signal transmission from the receiver to the transmitter, independent of the transmitter and receiver state, by determining and controlling the electromagnetic resonance condition, ensuring reliable communication even with fluctuations in resonant voltage.
Implementation Method 1
a resonance modulation circuit that varies an input impedance to switch whether an electromagnetic resonance condition is established
Implementation Method 2
the power transmitter includes a transmitting coil, and the power receiver includes a receiving coil
Implementation Method 3
a receiving circuit that converts high-frequency power received by the receiving resonant circuit into direct-current power
Data Source
AI summary
A transmitter has a transmitting resonant circuit, a transmitting circuit that supplies high-frequency power to the transmitting resonant circuit, and a demodulator. A receiver has a receiving resonant circuit; a receiving circuit that converts high-frequency power received by the resonant circuit into DC power; a load circuit that consumes the DC power; a resonance modulator that varies an input impedance, viewed toward the load circuit from the transmitting circuit, to switch whether an electromagnetic resonance condition is established; and a transmission-signal controller that converts a transmission signal into a variation pattern, representing a pattern of variation per predetermined time period of the input impedance, to control the resonance modulator. The demodulator detects a variable that varies with whether the electromagnetic resonance condition is established, and demodulates the transmission signal based on a pattern of variation per predetermined time period with respect to temporal variation of the variable.