Wireless Power Receiver Modulation Depth Control
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Solution Overview
Problem
Wireless charging systems experience audible noise due to increased modulation depth during inband communication, which affects the rectified voltage of electronic devices.
Innovation Solution
A power reception device equipped with a power reception circuit, communication circuit, and modulation depth monitoring circuit, including a processor that controls the modulation circuit to limit the modulation depth within a specified range, thereby reducing audible noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the modulation depth is increased to enable inband communication, then data transmission capability is improved, but audible noise increases
Solution Approach 1:
The patent implements dynamic modulation depth control by continuously monitoring the rectified voltage and adjusting the modulation depth accordingly. The system transitions from static to dynamic control, adapting the modulation depth in real-time based on operating conditions to maintain data transmission while minimizing audible noise.
Solution Approach 2:
The patent introduces a feedback mechanism where the rectified voltage is monitored and used to adjust the modulation depth. This closed-loop control ensures that the modulation depth is optimized based on actual system performance, preventing excessive noise while maintaining communication effectiveness.
2Loss of information
If the capacitance value of the capacitor is varied to modulate the signal, then inband communication is enabled, but the rectified voltage changes causing noise
Solution Approach 1:
The patent systematically varies capacitor capacitance values through switchable configurations to achieve different modulation depths. By providing multiple discrete capacitance options, the system can select the optimal value that enables communication while minimizing rectified voltage variation and associated noise.
3Object-affected harmful factors
If multiple detuning switching circuitries are used to control modulation depth, then noise reduction is improved, but device complexity increases
Solution Approach 1:
The patent divides the modulation control function into multiple independent detuning switching circuitries, each capable of controlling specific capacitors. This segmentation allows granular control over different aspects of the modulation process, enabling precise noise reduction while maintaining modular architecture that simplifies control logic.
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 audible noise by dynamically controlling the modulation depth, ensuring it stays within a set range, thereby improving the charging efficiency and noise reduction in wireless charging systems.
Implementation Method 1
a receive circuit configured to receive power from a wireless power transmitter and include a coil
Implementation Method 2
a rectifier circuit configured to rectify the power received by the receive circuit to convert the power into dual connectivity (DC) power
Implementation Method 3
each of which includes a second capacitor and a switch and changes a voltage of the power received in the coil
Data Source
AI summary
A power reception device is provided. The power reception device includes a power reception circuity, a communication circuit, a modulation depth monitoring circuit, and a processor electrically connected with the power reception circuity, the communication circuit, and the modulation depth monitoring circuit. The power reception circuity includes a receive circuit that receives power from a wireless power transmitter and includes a coil and a first capacitor and a rectifier circuit that rectifies the power received by the receive circuit to convert the power into dual connectivity (DC) power. The communication circuit includes a plurality of detuning switching circuitries, each of which includes a second capacitor and a switch and changes a voltage of the power received in the coil and a modulation circuit that turns on or off the switch based on a control signal received from the processor. The modulation depth monitoring circuit monitors a voltage of the rectified DC power to measure a modulation depth and provides the processor with the modulation depth. The processor identifies a detuning switching circuity to perform data modulation among the plurality of detuning switching circuitries based on the modulation depth, controls the modulation circuit such that data is modulated by means of the identified detuning switching circuity and limits the modulation depth such that the modulation depth belongs to a specified range, and controls the modulation circuit based on the data to be transmitted to the wireless power transmitter.