Abstract text

The invention concerns a method of amplifying a radio frequency signal, a switched mode power amplifying device and a radio transmission device comprising such a power amplifying device. The switched power amplifying device (10) comprises an envelope signal input (El), an arithmetic combining unit (SUB) between the envelope signal input and a modulating unit (PWM), configured to modulate a modified envelope signal (E′) output by the arithmetic combining unit with a carrier (C) for obtaining a modulated signal, an amplifying unit (PA) connected to the modulating unit providing an output signal (O) and a feedback path connected between the amplifying unit (PA) and the arithmetic combining unit (SUB). The feedback path comprises a low pass filter (LPF) for filtering the output signal (O) and a signal processing unit (DSP) processing the filtered signal (Vf) in order to obtain an estimated radio frequency amplitude (AE) for provision to the arithmetic combining unit.