Office of Technology Transfer – University of Michigan

Wideband wireless powering circuit

Technology #6537

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Researchers
Amir Mortazawi
Managed By
Joohee Kim
Licensing Specialist, Physical Sciences & Engineering 734.764.8202
Patent Protection
US Patent Pending

Background

Wireless Power Transfer (WPT) is being implemented to a wide range of applications including toothbrushes, smartphones and electric vehicles. Among WPT, inductive coupling technology is implemented to transfer power over a short distance of few millimeters and resonant coupling technology is implemented to transfer power over a longer distance of tens of centimeters to meters.

A typical resonant coupling WTP is composed of primary and secondary coils through which the power transfers and the resonance circuitry. The transfer power and power transfer efficiency of a resonant coupling WPT system is significantly impacted by the coupling factor of the coils. The coupling factor is a function of load, distance, misalignment and orientation of the coils. So in a conventional resonant coupling WPT system, the transfer power and its efficiency vary significantly as the load, distance, misalignment and orientation of the coils vary.

Technology

Inventors at the University of Michigan have developed a technology that can reduce the impact of such variations on the transfer power and its efficiency. Based on a first ever hardware realization of the Duffing equation, the demonstration circuitry implemented entirely of passive elements adjusted automatically to the variation of the coupling factor. A demonstration resonant coupling WPT system with the novel circuitry showed over 10x better tolerance to the variations in load, distance, misalignment and orientation of the coils over its conventional counterpart.

Applications

  • Mobile consumer devices
  • Electric vehicles
  • Biomedical implants
  • Ambient RF energy harvesting

Advantages

  • No quiescent power consumption
  • Simple configuration
  • Low cost
  • Reduced complexity
  • High reliability
  • Feasible for mass production