Abstract—This letter presents a new analytic design method for
impedance-matched wireless power transfer (WPT) systems using
an arbitrary number of coils. For deriving the impedance matching
condition, we have used an equivalent circuit of theWPT system. It
allows us to avoid solving voltage–current equations for the actual
circuit. For verifying the proposed design method, an impedancematched
WPT system with one repeater coil has been designed
and fabricated. This letter also shows that the distances between
the coils can be varied maintaining the impedance-matching performance,
and the distances can be determined analytically using
the presented design method. Application of the presented design
method can be found in designing WPT systems that require flexible
coil positioning.