3-d object comprising a sandwich of one or more composite layers, of one or more layers of metal patterns and optionally of one or more layers of possibly dense polymers for electromagnetic applications in antennas and/or radomes

A process for manufacturing a composite material of 3-D shape, comprising a stack of layers of resin and fibre and at least one layer of metal patterns, said process comprising the following steps, a periodic or pseudo-periodic organization in 2-D of first patterns similar to a standard unit pattern having been determined for said layer of metal patterns depending on the electromagnetic function desired for the layer of metal patterns:

• i/computing first patterns of said periodic organization once laid on the 3-D shape;
• then projecting, onto a plane, said patterns computed on the 3-D shape, thus defining a planar organization of second patterns;
• ii/partially polymerizing, flat, at least one sub-set of first layers of said stack, so as to make it etchable, but to keep it deformable, said first layers being flat and comprising at least one metal layer on the surface of said sub-set;
• iii/electrochemically etching said organization of second patterns that was defined in step i into the metal layer of the flat composite stack resulting from step
• iv/completely polymerizing the etched composite stack after said stack has been placed in a mould having the desired 3-D shape.