A WPT system with multiple receiver

A WPT system with multiple receivers and a transmitter for
effective WPT to multiple devices simultaneously is analyzed
by considering the cross coupling effect between non-adjacent
coils. It is shown that the cross coupling can have an important
influence on proper impedance matching and power transfer
efficiency, especially for a transmitter close to multiple
receivers. From the analysis results, a method of impedance
matching considering the cross coupling by using a single
source coil is proposed. Also, design procedure of the single
source coil and optimal load impedance are presented.
The simulated and measured results show that the WPT
system with three receivers by using the proposed method can
transfer efficiently wireless power to the maximum three
receivers at once, compared with the case without consideration
of the cross coupling. It is expected that the proposed method
can be well applied to a charging pad for multiple mobile
devices.