An RF amplifier for amplifying a composite RF signal includes a first RF signal and a second RF signal. The amplifier includes a first amplifying stage for providing a first amplified signal a second amplifying stage for providing a second amplified signal, a third amplifying stage for providing a third amplified signal and a fourth amplifying stage for providing a fourth amplified signal, the fourth amplifying stage being arranged after the third amplifying stage. The respective amplified signals are summed up to obtain amplified RF signals.