An antenna system includes a first transmission line, a second transmission line, a third transmission line, a fourth transmission line, a first dipole antenna, a second dipole antenna, a third dipole antenna, a fourth dipole antenna, a fifth dipole antenna, a sixth dipole antenna, a seventh dipole antenna, and an eighth dipole antenna. Each dipole antenna is coupled through a corresponding transmission line to a feeding point. Each of the fifth dipole antenna, the sixth dipole antenna, the seventh dipole antenna, and the eighth dipole antenna is positioned between the feeding point and a corresponding one of the first dipole antenna, the second dipole antenna, the third dipole antenna, and the fourth dipole antenna. Each of the partial dipole antennas includes a positive radiation branch and a negative radiation branch. The angle between the positive radiation branch and the negative radiation branch is less than 100 degrees.