Tunable Reactance Circuit for Wireless Power Impedance Matching
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Solution Overview
Problem
Wireless power systems face inefficiencies due to dynamic impedance variations between transmitters and receivers, leading to energy losses and heat issues, as existing technologies struggle to maintain optimal impedance matching across varying load conditions and coupling conditions.
Innovation Solution
The implementation of tunable reactance circuits, which include a switch controlled by a gate driver, a diode, and capacitors in parallel, allowing for adjustable capacitive reactance based on the switch's on-time and total capacitance, enabling continuous or discrete tuning of reactance to match changing impedance conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fixed impedance matching is used in wireless power systems, then the circuit design is simple, but power transmission efficiency deteriorates under varying load and coupling conditions
Solution Approach 1:
The patent implements dynamic impedance matching by making the reactance value adjustable through a switchable capacitor network. The capacitor bank can be dynamically reconfigured to change the total capacitance value, allowing the impedance matching network to adapt to varying load conditions and coupling conditions, thereby maintaining optimal power transmission efficiency across different operating scenarios.
Solution Approach 2:
The patent changes the electrical parameter (capacitance value) of the impedance matching network by switching different capacitor combinations into or out of the circuit. This parameter adjustment enables the system to optimize power transmission efficiency under different operating conditions without requiring a completely different circuit design.
2Loss of energy
If impedance matching is optimized for specific conditions, then power transmission efficiency is improved, but adaptability to varying conditions deteriorates
Solution Approach 1:
The patent makes the impedance matching network dynamic by enabling real-time adjustment of capacitance values through the switchable capacitor bank. This dynamic capability allows the system to maintain optimized power transmission efficiency across a range of varying load and coupling conditions, rather than being fixed for a single operating point.
Solution Approach 2:
The patent creates a universal impedance matching solution that can handle multiple operating conditions through the switchable capacitor network. By providing multiple capacitance values that can be selected based on conditions, the single circuit design serves multiple functions and adapts to various scenarios, improving both efficiency and versatility.
3Adaptability or versatility
If switchable capacitor bank is used for tuning reactance, then adaptability to impedance variations is improved, but device complexity increases
Solution Approach 1:
The patent segments the total capacitance into multiple discrete capacitor units that can be independently switched. This segmentation allows for granular adjustment of the total capacitance value, providing fine-tuned reactance control. The modular structure also simplifies the switching control logic compared to using a single variable capacitor.
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 solution enhances power transmission efficiency by dynamically adjusting reactance to match varying impedance, reducing energy losses and heat, and ensuring reliable power delivery to loads across different coupling conditions.
Implementation Method 1
one or more capacitors coupled in parallel to the diode, wherein the tunable capacitive reactance can be based on the on-time of the switch and a total capacitance value of the one or more capacitors
Implementation Method 2
a switch configured to be controlled by a gate driver, in which the gate driver is configured to receive a control signal indicating an on-time of the switch
Implementation Method 3
a resonator configured to generate an electromagnetic field based on the driving signal
Implementation Method 4
configured to transmit power to one or more wireless power receivers via an oscillating electromagnetic field
Data Source
AI summary
Disclosed herein are tunable reactance circuits configured to present a tunable or variable capacitive reactance when energized. The circuits can include a switch configured to be controlled by a gate driver, the gate driver configured to receive a control signal indicating an on-time of the switch; a diode coupled antiparallel to a switch; and one or more capacitors coupled in parallel to the diode. The tunable capacitive reactance can be based on the on-time of the switch and a total capacitance value of the one or more capacitors. The exemplary tunable reactance circuits may be used in wireless power transmitters and/or receivers for efficient power transmission and/or to deliver a particular level of power to a load.