Patent ID: 8154467

Claim:
An antenna apparatus comprising: a base having a first face and a second face; two radiation elements arranged parallel to each other on the first face of the base; and a parasitic element disposed between the two radiation elements on the first face of the base, wherein radiation directivity of the two radiation elements is controlled according to a length of the parasitic element, wherein the parasitic element, which is shorter than the radiation elements, functions as a director and tilts directional peaks toward the radiation elements, wherein the radiation elements and the parasitic element respectively include a planar plate portion substantially parallel to the base, a short-circuited plate portion extending from one end of the planar plate portion to be short-circuited to the base, and an opening portion formed by an opposite end of the planar plate portion spaced apart from the base, wherein each of the opening portions of the two radiation elements is opened in a predetermined first direction, and the opening portion of the parasitic element is opened in a direction opposite of the direction, wherein the radiation elements are supplied power and the parasitic element is not supplied power, and wherein short-circuited plate portions of the radiation elements are positioned at one end of the base and a short-circuited plate portion of the parasitic element is positioned apart from the one end of the base.