According to an embodiment, the FPC 220 may include a first region 221 and a second region 222. The first region 221 may be a region in which the plurality of antenna elements 231, 232, 233, and 234 are mounted. In an embodiment, in the first region 221, the millimeter wave signal may be radiated from the plurality of antenna elements 231, 232, 233, and 234. The second region 222 may be a region including the ground. In this specification, the ground may be referred to as an “FPC ground”. In this specification, the wire for feeding a plurality of antenna elements may be positioned in the second region 222.
According to an embodiment, the FPC ground may reduce at least part of a millimeter wave signal radiated from the antenna elements 231, 232, 233, and 234, for example, a component radiated in the direction (e.g., ?X axis direction) of the FPC 220. In this case, the millimeter wave signal may not arrive at a dielectric substance present in a direction of the FPC 220, for example, at a partial region of the front surface of the housing 110 or a partial region of the rear surface of the housing 110.