An antenna comprises a ground element, a conductive element, a signal line, a first transmitting element, a second transmitting element. The conductive element is L-shaped and connected to the ground element. The signal line is coupled to the conductive element. The first transmitting element is connected to the conductive element for transmitting a first signal. The second transmitting element is connected to the conductive element for transmitting a second signal. The first signal is a GSM900 signal and the second signal is a DCS1800 signal.