Patent ID: 8653910

Claim:
A high-frequency signal transmission line comprising: an element assembly formed of one or more insulating layers, the element assembly having a first main surface and a second main surface; a linear signal line disposed in the element assembly; a first ground conductor that is disposed in the element assembly, faces the signal line, and continuously extends along the signal line, the first ground conductor being located near the first main surface with respect to the signal line; and a second ground conductor that is disposed in the element assembly, faces the first ground conductor via at least one of the one or more insulating layers, and has a plurality of openings arranged along the signal line, the second ground conductor being located near the second main surface with respect to the signal line; wherein the element assembly has a connection used for external connection, and a transmission line which a part of the first ground conductor extending along the signal line functions as; wherein the first main surface of the element assembly is a contact surface with a metal article; and wherein the first ground conductor is electrically connected to the metal article by connection between the transmission line and the metal article via solder or a conductive adhesive.