Power Optimized Waveform for Wireless Charging Diode Loss
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Solution Overview
Problem
Conventional wirelessly powered devices face limitations in range and power efficiency due to inefficient power waveforms, with significant energy loss occurring at the diodes of charge pumps, restricting the range, sensitivity, reliability, and power efficiency of these devices.
Innovation Solution
A power optimized waveform is introduced, featuring a charge portion with a maximum voltage at least double the Root Mean Square (RMS) voltage of the starve portion, minimizing energy loss by delivering the majority of the energy in a small number of pulses rather than equally across each pulse, thus reducing dissipation at the diodes of the charge pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional power waveforms are used to power wirelessly powered devices, then the devices can operate within a limited range, but the power efficiency is poor with significant energy loss at the diodes of charge pumps
Solution Approach 1:
The patent applies periodic action by using a pulsed power waveform with alternating charge and starve portions. The charge portion delivers energy to the charge pump capacitors, while the starve portion allows the capacitors to supply power to the load. This periodic charging and discharging cycle optimizes power transfer efficiency and reduces energy loss at the diodes compared to continuous waveforms.
Solution Approach 2:
The patent changes the voltage parameter dynamically by setting the maximum voltage of the charge portion to be at least double the RMS voltage of the starve portion. This parameter optimization ensures that the charge pump diodes operate in a regime where their forward voltage drop causes minimal power loss, thereby improving overall power efficiency while maintaining reliable device operation.
2Loss of energy
If the maximum voltage of the charge portion is increased to at least double the RMS voltage of the starve portion, then power efficiency is improved, but the waveform complexity increases
Solution Approach 1:
The waveform complexity is managed by using a simple periodic structure with two distinct portions (charge and starve) rather than complex modulated waveforms. The regular repetition of these two portions makes the waveform easy to generate and synchronize, while still achieving the voltage ratio needed for optimal power efficiency.
Solution Approach 2:
The patent simplifies waveform generation by focusing on controlling just two key parameters: the duration of the charge and starve portions, and the maximum voltage ratio between them. This reduces the complexity compared to more sophisticated power transmission waveforms that would require multiple frequency components or complex modulation schemes.
3Loss of energy
If energy is delivered equally across each pulse, then the power distribution is uniform, but energy loss at the diodes increases significantly
Solution Approach 1:
The patent uses periodic action with distinct charge and starve portions where the charge portion delivers energy in concentrated pulses to the charge pump capacitors. This non-uniform periodic delivery concentrates power transfer during specific intervals, allowing the diodes to operate more efficiently during charging while the capacitors handle power delivery during the starve portion, reducing overall diode dissipation.
Solution Approach 2:
The charge portion performs preliminary action by pre-charging the charge pump capacitors to a high voltage (at least double the RMS voltage of the starve portion) before the starve portion begins. This preliminary energy storage in the capacitors allows subsequent power delivery to occur with minimal additional diode involvement, thereby reducing energy loss at the diodes while maintaining effective power delivery to the load.
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 enhances the power efficiency and range of wirelessly powered devices by minimizing energy loss, improving the overall performance and reliability while maintaining a low overall RMS voltage, suitable for applications like RFID systems and portable electronics.
Implementation Method 1
receiving a power waveform to the wirelessly powered device from the wireless power transmission system, wherein each cycle of the power waveform includes a charge portion and a starve portion
Data Source
AI summary
The present invention describes systems and methods for providing a power optimized waveform. An exemplary embodiment of the present invention provides a method of powering wirelessly powered devices including the step of providing a wirelessly powered device and a wireless power transmission system. Furthermore, the method involves receiving a power waveform to the wirelessly powered device from the wireless power transmission system, wherein each cycle of the power waveform includes a charge portion and a starve portion. Additionally, the maximum voltage of the charge portion is at least double the Root Mean Square (“RMS”) voltage of the starve portion.