A multiband antenna includes main antenna, a switch circuit, and a parasitic antenna. The main antenna includes a radiating portion, a feeding portion, a grounding portion, and an extending portion coupled to the feeding portion and the grounding portion. The radiating portion is configured to generate a low frequency resonate mode. The switch circuit is configured to regulate an impedance matching characteristic of the multiband antenna, thereby regulating an operating frequency of the low frequency resonate mode. The parasitic antenna is positioned apart from and electromagnetically coupled to the main antenna, and configured to generate a high frequency resonate mode.