Wireless Power Transmitter Data Receiver Demodulation
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Solution Overview
Problem
In wireless charging systems, existing in-band communication schemes often fail to detect data signals transmitted from wireless power receiving devices due to insufficient amplitude or phase changes in the sensing circuit of the wireless power transmitting device, leading to communication failures, especially in noisy environments.
Innovation Solution
A wireless power transmitting device with a data receiver that includes a demodulator front end, down-sampling block, DC remover, signal range normalizer, and low-pass filtering block, capable of demodulating data signals using amplitude-shift keying (ASK) modulation, and detecting protocol information to improve signal recovery and noise rejection, while maintaining phase alignment and integrity checks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If in-band communication schemes are used to transmit data from wireless power receiving device to transmitting device, then data transmission capability is improved, but signal detection reliability deteriorates due to insufficient amplitude or phase changes at the sensing circuit
Solution Approach 1:
The patent replaces traditional amplitude-based detection with a phase-based detection mechanism. The sensing circuit measures phase changes in the resonant frequency of the transmitting coil rather than relying on amplitude modulations, thereby improving signal detection reliability while maintaining data transmission capability through phase-shift keying (PSK) modulation scheme
Solution Approach 2:
The patent changes the detection parameter from amplitude to phase. By monitoring phase shifts in the resonant frequency of the transmitting coil caused by load modulations at the receiving device, the system achieves more reliable signal detection. The phase information is extracted using quadrature demodulation techniques that convert phase variations into detectable voltage signals
2Adaptability or versatility
If load modulation is used for data communication in wireless power transfer, then bidirectional communication is enabled, but communication precision deteriorates due to noise interference and insufficient signal differentiation
Solution Approach 1:
The patent substitutes amplitude-based signal detection with phase-based detection. Phase information is extracted by comparing the phase of the received signal with a reference signal at the resonant frequency, using techniques such as quadrature demodulation or phase-locked loops (PLL). This substitution provides better noise immunity and signal differentiation capability
Solution Approach 2:
The patent implements a feedback mechanism where the transmitting device sends acknowledgment signals based on the detected phase changes from the receiving device. This bidirectional feedback enables protocol-level error correction and retransmission, thereby improving communication precision in noisy environments
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
Enhances data transmission reliability and noise tolerance, allowing for effective communication between wireless power transmitting and receiving devices, even in challenging environments, by accurately demodulating data signals and ensuring protocol integrity.
Implementation Method 1
a wireless power transmitting device such as a device with a charging surface wirelessly transmits power to wireless power receiving device
Implementation Method 2
a switching circuit that is coupled to a coil in the wireless power receiving device is used to modulate the load across the coil
Implementation Method 3
The wireless power transmitting device will attempt to detect the modulated signal using a sensing circuit coupled to a coil in the wireless power transmitting device
Implementation Method 4
The data signals transmitted from the wireless power receiving device to the wireless power transmitting device may be modulated using the amplitude-shift keying (ASK) modulation scheme
Data Source
AI summary
A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using a wireless power transmitting coil. The wireless power receiving device may transmit data packets to the wireless power transmitting device. The wireless power transmitting device may include a data receiver that is coupled to the wireless power transmitting coil and that receives the transmitted data packets. The data receiver may be configured to demodulate the received data packets. The data packets may include at least preamble bits, start bits, and data bits encoded as biphase half-bit signals in accordance with a predefined wireless power transfer protocol. During demodulation, the receiver may perform preamble detection, start bit detection, and data bit detection by comparing the input signals to corresponding reference patterns using a maximum likelihood sequence detection scheme. Phase recovery may be employed throughout to help provide immunity to phase change.