This conference gives an aperture of WCIP towards interesting applications in non homogenous metamaterials. Up to now, the metamaterials are considered as homogeneous, permitting the determination of their equivalent medium. The link between a metamaterial and a device (patch antenna for instance),or another material presents difficulties and is not approached except in some global analysis. A generalization of the WCIP is presented. It’s consists in almost periodic circuits described by lumped elements. There are many applications for this kind of structures, as filters, or power amplifiers.