A radio system for communication is provided that has a differential
amplifier for amplifying a transmission frequency, particularly 2.4 GHz,
wherein the differential amplifier has a first inductor, which is
magnetically coupled to a second inductor, and a capacitor. The
capacitor, the first inductor, and the second inductor are wired into a
resonant circuit in such a way that the resonant circuit has a
common-mode impedance for a common-mode signal and a push-pull impedance,
different from the common-mode impedance, for the push-pull signal.