A matching network for matching an antenna to a transmitter or receiver comprises an input port for receiving high-frequency power, an output port and a switchable impedance transformation circuit, which is connected between the input port and the output port. The impedance transformation circuit comprises a CMOS switch in a high-frequency path, which has a first switching state and a second switching state. The impedance transformation circuit is implemented to match a first impedance applied to the output port to a first predetermined impedance in the first switching state, and to match a second impedance applied to the output port to a second predetermined impedance in the second switching state. The inventive matching network allows a particularly good utilization of power provided by a transmitting amplifier or an antenna.