Patent ID: 7746286

Claim:
An antenna device formed by patterning a metal conductor on a printed substrate, comprising: a ground pattern of an approximately rectangular shape having two short sides and two long sides; a parasitic radiation element extending along an extension direction substantially in parallel with a first short side of the ground pattern, the parasitic radiation element being provided at a certain distance apart from the first short side of the ground pattern so as to provide a space between the parasitic radiation element and the first short side of the ground pattern; a power feed element provided in the space between the parasitic radiation element and the ground pattern, the power feed element having a power feed point to which a power feed signal is supplied; and a correction pattern provided in the space between the parasitic radiation element and the ground pattern, the correction pattern projecting from the first short side of the ground pattern and is located lateral to the power feed element, wherein an electrical length of the parasitic radiation element is set to be approximately ½ of a resonant length.