An antenna system with two antennas provides the possibility to operate at least two different radio communication systems with one radio communication system operating on one single antenna of the antenna system and another radio communication system operating on both antennas of the antenna system wherein the antenna system serves as a diversity antenna system. This kind of antenna system is designed to be employed particularly in small devices with restricted measurements. Especially, an implementation of an antenna system for dual use of GSM/E-GSM/DCS operation and WLAN operation is presented.