An antenna system for providing identification functionality comprising a main antenna and an auxiliary antenna, wherein the antennas are configured to at least transmit electromagnetic waves. The antenna system comprises a first channel interface and a second channel interface, a first switch and a transmission input means. The first switch is configured to switch between a first operation mode and a second operation mode. When set in the first operation mode the second channel interface is set to be in connection with the auxiliary antenna and when set in the second operation mode the second channel interface is set to be in connection with the main antenna. If transmission via the first transmission channel is expected the transmission input means is configured to set the first switch in the first operation mode. Thereby the main antenna can be used for transmission of signals both provided via the first and second channel interfaces and when transmission via the first and second channel interfaces simultaneously is required the signal provided via the first channel interface will be transmitted by the main antenna and the signal provided via the second channel interface will be transmitted by the auxiliary antenna.