Planar resonator

A planar resonator 100, or a method suitable for its manufacture, which is suitable for wireless power transfer, comprises: first and second two-dimensional arrays of conductive elements 102, 104 which are separated by a dielectric material layer 106, wherein each conductive element of the first, or second, array at least partially overlaps with one or more of the conductive elements of the second, or first, array, respectively. The resonator may have a structure where each conductive element of a respective array does not overlap with any of the other elements of that array. A further dielectric material layer may be provided to separate the second array of elements 104 from a third two-dimensional array of conductive elements and where each of the second array conductive elements partially overlaps with one or more of the conductive elements of the third array. A dielectric layer 106 may be substantially planar and the conductive elements 102, 104 may be printed in a substantially square planar array where the elements of one or more arrays may be identical to one another and the dielectric layer and the elements may be made of flexible or rigid material. Each array may be spatially offset from each adjacent array. The resonator may include an encapsulation layer of material and it may be used in a textile of a garment.