An antenna device includes a first antenna, a second antenna, a barrier, and a signal processing device. The first antenna transceives a first radio frequency (RF) signal in a first communication band, and the second antenna transceives a second RF signal in a second communication band. The first antenna includes a first radiator and a second radiator having a shape symmetrical to a shape of the first radiator. The second antenna includes third and fourth radiators having shape identical to those of the first and second radiators but having a size corresponding to the second communication band. The barrier includes a penetration region, and reflects the first and second RF signals. A center frequency of the second communication band is higher than a center frequency of the first communication band, and the first and second antennas are connected with the signal processing device through the penetration region of the barrier.