An antenna system includes a dual-polarized antenna, a main reflector, and an auxiliary reflector. The dual-polarized antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element operate in a low-frequency band and a high-frequency band. The first antenna element and the second antenna element have different polarization directions. The main reflector is configured to reflect the electromagnetic waves in the low-frequency band. The auxiliary reflector is positioned between the dual-polarized antenna and the main reflector, and is configured to reflect the electromagnetic waves in the high-frequency band.