A broadband antenna includes a radiation part (10) for radiating and receiving electromagnetic signals, a feed portion (30) for feeding the electromagnetic signals, and a pair of ground planes (40) respectively disposed on sides of the feed portion. The radiation part comprises an annular first radiation segment (12) and an annular second radiation segment (14) being inscribed within a space defined by the annular shape of the first radiation segment. The feed portion is electrically connected to the radiation part.