An Experimental Technique for Design of Practical Wireless Power Transfer Systems

Wireless Power Transfer using magnetically coupled resonators has been widely used for biomedical and consumer electronics applications. However, typical analysis of wireless power transfer has focused on standard operating conditions (linear power source and fixed impedances Z(s) = Z(L) = Z(0)) and is not applicable for practical applications. In this work we use experimentally obtained S-parameters to accurately model and analyze a WPT system driven by a linear or non-linear power source with arbitrary source impedance (Z(s)) delivering power to an arbitrary load impedance (Z(L)). Using this approach, we define a framework to evaluate the performance of WPT in terms of two metrics i.e. efficiency and power delivered to the load. The proposed technique can help designers accurately predict and analyze the behavior of WPT systems in practical applications.