These file attachments have been under embargo and were made available to the public after the embargo was lifted on 10 February 2012.
In inductive wireless power transmission system a lateral displacement of the receiver coil to the transmitter coil leads to a change ofthe coupling factor and thus an unwanted variation of the power transfer. Here, an algorithm to determine the turn distribution to achieve homogeneous coupling between coils of different diameter is described. As long as the coils overlap, the variation of the coupling factor is very low. To achieve a lateral displacement over an even larger area, an array of transmitter coils can be used. The size of the receiver coil is selected such that it always covers a complete transmitter coil. If only the covered transmitter coil is activated by a suitable detection circuit, the power transmission area can be arbitrary large with homogeneous magnetic coupling.