Patent attributes
An antenna device includes a finite ground plane that includes a linear side, a first conductor plate that faces the finite ground plane and includes a side corresponding to the side of the finite ground plane and having a length of substantially a ⅛ wavelength or less, and a conductor line that includes one end connected to the side of the first conductor plate and the other end short-circuited to one end portion of the side of the finite ground plane. The antenna device further includes a second conductor plate that faces the finite ground plane, includes a side corresponding to the side of the finite ground plane and having a length of substantially a ⅛ wavelength or less, and is arranged to be adjacent to the first conductor plate to perform capacitive coupling with the first conductor plate and a feed line that includes one end connected to the side of the second conductor plate and the other end connected to the other end portion of the side of the finite ground plane.