Image impedances of magnetic resonant wireless power transfer links

In magnetic resonant wireless power transfer the free-space part of the link is realized by using coupled inductances and by adding appropriate series capacitances (so as to obtain resonance). By introducing appropriate reactive matching networks, we remain with a two port lossy network. In this work it is shown that, by taking as reference impedance the image impedances of the two port lossy network, we realize a system with the maximum efficiency. Such a system, in addition, does not suffer from frequency shifts of resonances and similar phenomena. An experimental verification of the proposed approach is also presented.