Patent ID: 7623004

Claim:
An RF device for guiding RF energy, comprising: wall structures formed of a metallic wall material and defining a channel through which said RF energy travels, said metallic wall material having a wall material surface; a porous layer disposed over said wall material surface and having a porous layer upper surface opposite a porous layer lower surface facing said wall material surface, said porous layer defining pores with openings distributed in said porous layer upper surface, said porous layer being disposed on said wall material surface; a conductive layer disposed over said porous layer upper surface, said conductive layer being disposed on said porous layer upper surface in a thickness so as to be conductive at RF frequencies; and said pores having pore walls and said conductive layer being disposed on said pore walls so as to conforming to at least portions of the said pore walls, without filling said openings at said porous layer upper surface so as to leave voids; and also be contiguous with portions of said conductive layer on said porous layer upper surface.