A multi-layer electromagnetic coupler arrangement for coupling electromagnetic power to a planar metallic trace (1, 48) of arbitrary geometric shape, the electromagnetic coupler arrangement comprising: a top surface layer forming a top surface of the electromagnetic coupler arrangement to be arranged closest to the metallic trace (1, 48) to which the electromagnetic power is to be coupled; a dielectric layer a surface of which is covered by said top surface layer; an input signal source layer for providing an AC electromagnetic input field signal; a transmission line network comprising a three layer printed circuit board provided between said input signal source layer and said dielectric layer, the layer of the three layer printed circuit board adjacent to the signal source layer comprising transmission line segments having a predetermined electrical length, the transmission line network comprising a one- or two-dimensional array (3, 4, 5, 40, 44, 46) of phase altering elements the size and mutual arrangement of which is configured to provide for a phase compensation for the spatial change of position between each of said phase altering elements and a neighboring one, thereby transforming the input field signal into a distributed electromagnetic field with substantially constant phase across the top surface; each of said phase altering elements including a network of lumped or distributed components (40, 44) for achieving phase compensation for the predetermined electrical length of the respective transmission line segment and forming, together with the respective transmission line segment a phase compensated element, said components (40, 44) comprising an inductive component (40, L) and at least one capacitive component (44, C 1, C 2), the inductive components (40, L) of the phase altering element being realized in distributed form as inductive loops, wherein said loops are disposed on the side of the three layer printed circuit board adjacent to the dielectric layer, the at least one capacitive component (44, C 1, C 2) being distributed between transmission line segments on the side of the three layer printed circuit board adjacent to the input signal source layer, the intermediate layer of the three layer printed circuit board comprising a ground plane, the inductive loops, the ground plane and the transmission line segments being connected through vias, said input signal source layer comprising a strip transmission line and is configured to provide a guided wave input signal having a target wavelength, said target wavelength being a wavelength of propagation in a homogeneous dielectric of the material of said dielectric layer, and a size of each of said phase altering element being significantly smaller than one half of said target wavelength. a top surface layer forming a top surface of the electromagnetic coupler arrangement to be arranged closest to the metallic trace (1, 48) to which the electromagnetic power is to be coupled; a dielectric layer a surface of which is covered by said top surface layer; an input signal source layer for providing an AC electromagnetic input field signal; a transmission line network comprising a three layer printed circuit board provided between said input signal source layer and said dielectric layer, the layer of the three layer printed circuit board adjacent to the signal source layer comprising transmission line segments having a predetermined electrical length, the transmission line network comprising a one- or two-dimensional array (3, 4, 5, 40, 44, 46) of phase altering elements the size and mutual arrangement of which is configured to provide for a phase compensation for the spatial change of position between each of said phase altering elements and a neighboring one, thereby transforming the input field signal into a distributed electromagnetic field with substantially constant phase across the top surface; each of said phase altering elements including a network of lumped or distributed components (40, 44) for achieving phase compensation for the predetermined electrical length of the respective transmission line segment and forming, together with the respective transmission line segment a phase compensated element, said components (40, 44) comprising an inductive component (40, L) and at least one capacitive component (44, C 1, C 2), the inductive components (40, L) of the phase altering element being realized in distributed form as inductive loops, wherein said loops are disposed on the side of the three layer printed circuit board adjacent to the dielectric layer, the at least one capacitive component (44, C 1, C 2) being distributed between transmission line segments on the side of the three layer printed circuit board adjacent to the input signal source layer, the intermediate layer of the three layer printed circuit board comprising a ground plane, the inductive loops, the ground plane and the transmission line segments being connected through vias, said input signal source layer comprising a strip transmission line and is configured to provide a guided wave input signal having a target wavelength, said target wavelength being a wavelength of propagation in a homogeneous dielectric of the material of said dielectric layer, and a size of each of said phase altering element being significantly smaller than one half of said target wavelength.