Analysis of Efficiencies for Multiple-Input Multiple-Output Wireless Power Transfer Systems

  • Kim, Sejin ;
  • Lee, Bomson
  • Received : 2016.01.04
  • Accepted : 2016.04.04
  • Published : 2016.04.30


Wireless power transfer (WPT) efficiencies for multiple-input multiple-output (MIMO) systems are formulated with a goal of achieving their maximums using Z matrices. The maximum efficiencies for any arbitrarily given configurations are obtained using optimum loads, which can be determined numerically through adequate optimization procedures in general. For some simpler special cases (single-input single-output, single-input multiple-output, and multiple-input single-output) of the MIMO systems, the efficiencies and optimum loads to maximize them can be obtained using closed-form expressions. These closed-form solutions give us more physical insight into the given WPT problem. These efficiencies are evaluated theoretically based on the presented formulation and also verified with comparisons with circuit- and EM-simulation results. They are shown to lead to a good agreement. This work may be useful for construction of the wireless Internet of Things, especially employed with energy autonomy.


Coupling Coefficient;Optimum Load Resistance;Transfer Efficiency;Wireless Power Transfer;Z Matrix


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Supported by : National Research Foundation of Korea (NRF)