Patent ID: 7176837

Claim:
An antenna device comprising: a dielectric member or a dielectric substrate and a radiating conductor formed in or on the dielectric member or the dielectric substrate, the radiating conductor being formed in a planar shape; the radiating conductor having a conductor shape defined by a first forming element, a second forming element and a third forming element disposed in one direction, the radiating conductor being configured in such a single shape that the first forming element and the second forming element are jointed together and that the second forming element and the third forming element are jointed together; the first forming element being formed in a shape selected among a semi-circular shape, a substantially semi-circular shape, a semi-oval shape, a substantially semi-oval shape, an arched shape and a substantially arched shape; the third forming element being formed in a shape selected among a band-like shape, a substantially band-like shape, a rectangular shape and a substantially rectangular shape; the first forming element and the third forming element being disposed to be apart from each other; the second forming element being disposed to bridge a gap between the first forming element and the third forming element; and the third forming element having a feed point disposed therein; wherein when it is assumed that the semi-circular shape, the substantially semi-circular shape, the semi-oval shape, the substantially semi-oval shape, the arched shape and the substantially arched shape of the first forming element has a chord extended beyond the second forming element to an edge portion of the third forming element remote from the first forming element, and that the extended portion of the chord is called an imaginary chord, an edge portion of the second forming element close to the imaginary chord and one side of the third forming element close to the imaginary chord overlap or substantially overlap with the imaginary chord; and wherein when maximum vertical lengths of the first forming element, the second forming element and the third forming element in a direction orthogonal to the one direction are represented by W 1 , W 2 and W 3 , respectively, W 1 , W 2 and W 3 are set to satisfy the condition of W 1 >W 2 >W 3 .