Patent ID: 8665142

Claim:
An antenna device comprising: a dielectric substrate having a first surface covered by a first metal film and a second surface covered by a second metal film; a first via-hole row and a second via-hole row in each of which via holes are arranged, wherein the first via-hole row is spaced apart from the second via-hole row by a predetermined interval in the dielectric substrate; a waveguide line defined by a region in the dielectric substrate surrounded by the first via-hole row, the second via-hole, the first metal film, and the second metal film; and a slot pair provided in the first metal film, wherein: the slot pair has a first slot and a second slot provided so that a slot length direction is oblique to a line direction of the waveguide line, a center of the first slot and a center of the second slot are spaced apart from each other by not less than a half of a shorter one of a slot length of the first slot and a slot length of the second slot along the slot length direction, and the center of the first slot and the center of the second slot are spaced apart from each other by an interval of approximately ¼ of a guide wavelength of the waveguide line along the line direction of the waveguide line.