Patent attributes
An antenna device includes an antenna substrate 30 and a multilayer substrate 36 mounted on the antenna substrate 30. The antennal substrate 30 includes an insulating part 31, an antenna element 32 composed of a conductor pattern formed on a predetermined principal surface and a ground part 34 connected to the antenna element 32 electrically and formed on the principal surface. The multilayer substrate 36 includes a wiring pattern formed in an inside layer, an opening through which the wiring pattern is exposed on the side of one principal surface of the multilayer substrate 36, a plurality of through-holes formed so as to surround the opening and penetrate the inside layer of the multilayer substrate 36 while extending from the one principal surface and a ground layer 38 arranged to make contact with respective other ends of the through-holes and arranged in a position to interleave the wiring pattern against the opening. The antenna substrate 30 is electrically joined to the multilayer substrate 36 through the through-holes.