An adaptive near field electromagnetic coupler for coupling electromagnetic power to a plane metallic trace (inlay) independently of the inlay geometry and/or orientation without external control algorithms. This is achieved by employing a microstructure of phase altering elements suitable for creating a constant phase field distribution along a top surface of the coupler structure. This is advantageously applicable to printing devices having a function of encoding RFID layers printed on a medium. In view of the provided flexibility, the coupler arrangement can be employed in a variety of printers of different mechanical design.