Abstract: An antenna assembly having patterned conductive films on the surfaces of a dielectric hexahedron with compatibility to mass-production, wherein the conductive films are formed on protuberances formed on the surface of the dielectric hexahedron on which protuberances and depressions are formed. In one embodiment, the dielectric hexahedron includes convex portions serving as the protuberances and concave portions serving as the depressions. A conductive film may be formed on the protuberances by roll coating, sputtering, evaporative deposition, and electroless deposition, thereby producing inexpensively a high quality antenna assembly having a circuit pattern formed thereon.

Abstract: The present invention relates to an antenna device to be used for portable communication sets and a method for reducing the manufacturing cost thereof. The antenna device includes a substrate having at least one of a dielectric material and a magnetic material and having upper and lower faces as well as a pair of side faces on which convex portions and concave portions are alternately formed. Also included is a helical conductor layer formed on the upper and lower faces, and on the concave portion or convex portion on a pair of the side faces of the substrate so as to spirally surround the entire substrate.