An antenna assembly includes an antenna region having conductive patterns □ on one side surface of a dielectric substrate to radiate radio signals. The antenna region includes a first antenna structure and a second antenna structure. The antenna assembly further includes a ground region formed on a same plane as the antenna region. The ground region includes a first slot region and a second slot region. A first feeding line is disposed at the first slot region, and a second feeding is disposed at the second slot region. The antenna region comprises a first conductive pattern, a second conductive pattern, a third conductive pattern, a fourth conductive pattern and a fifth conductive pattern.