Patent ID: 6870438

Claim:
A wiring board comprising: a dielectric substrate; a signal transmission line disposed on one surface of said dielectric substrate; a grounded layer disposed on the other surface of said dielectric substrate; and a connection portion for connecting the signal transmission line to a waveguide, said connection portion being disposed on the grounded layer; wherein said grounded layer has a slot at a position opposed to an end of said signal transmission line; and wherein said connection portion includes a first dielectric layer disposed so as to cover substantially the whole surface of the grounded layer disposed on the other surface of said dielectric substrate, a second dielectric layer is laminated on the first dielectric layer, and a patch conductor provided in an interface between said first dielectric layer and said second dielectric layer, a portion of said first dielectric layer positioned on said slot provides the first dielectric portion, and a portion of said second dielectric layer positioned over said slot provides the second dielectric portion.