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

• Published in: Journal of Electromagnetic Engineering and Science Vol. 16; no. 2; pp. 126 - 133
• Main Authors: Bomson Lee, Sejin Kim
• Format: Journal Article
• Language: English
• Published: 한국전자파학회JEES 01-04-2016; 한국전자파학회
• Subjects: 전자/정보통신공학; Wireless Power Transfer; Coupling Coefficient; Z Matrix; Optimum Load Resistance; Transfer Efficiency
• ISSN: 2671-7255; 2671-7263
• DOI: 10.5515/JKIEES.2016.16.2.126

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. KCI Citation Count: 5