Patent attributes
First and second monopole conductive elements are disposed so as to be approximately mutually perpendicular and so that respective open ends are adjacent, and with respect to a straight line that passes between open ends of the first and second monopole conductive elements and through a center of a conductive ground plane, a first conductive ground plane portion formed on a first monopole conductive element-side of the straight line among the conductive ground plane and the first monopole conductive element are formed so as to be approximately symmetrical to a second conductive ground plane portion formed on a second monopole conductive element-side of the straight line among the conductive ground plane and the second monopole conductive element.