An amplifier circuit for providing a radio frequency output signal having a variable signal envelope, comprising - a main amplifier device having an input and an output for outputting a first radio frequency output signal; - an auxiliary amplifier device having an input and an output for outputting a second radio frequency output signal; - a combiner network for combining at least a component of said first radio frequency output signal from said first amplifier device and at least a component of said second radio frequency output signal from said second amplifier device to provide a combined output signal of variable signal envelope to a load (Z L); - a signal processing circuit comprising -- an input (In) for receiving an input signal; -- a first output coupled to the input of the main amplifier device for providing a first radio frequency signal to be amplified by said first amplifier device; and -- a second output coupled to the input of the second amplifier device for providing a second radio frequency signal to be amplified by said second amplifier device; - wherein said signal processing circuit comprises a non-linear processing section (31; 41) coupled to the input of the signal processing circuit and adapted to provide at least said second radio frequency signal with a signal envelope that has a non-linear dependency (f) from an amplitude characteristic of the input signal (In); wherein - the non-linear processing section (31; 41) is adapted such that the degree of non-linearity of the non-linear dependency (f) varies dependent on the amount of change per time unit of the amplitude characteristic of the input signal (In). - a main amplifier device having an input and an output for outputting a first radio frequency output signal; - an auxiliary amplifier device having an input and an output for outputting a second radio frequency output signal; - a combiner network for combining at least a component of said first radio frequency output signal from said first amplifier device and at least a component of said second radio frequency output signal from said second amplifier device to provide a combined output signal of variable signal envelope to a load (Z L); - a signal processing circuit comprising -- an input (In) for receiving an input signal; -- a first output coupled to the input of the main amplifier device for providing a first radio frequency signal to be amplified by said first amplifier device; and -- a second output coupled to the input of the second amplifier device for providing a second radio frequency signal to be amplified by said second amplifier device; -- an input (In) for receiving an input signal; -- a first output coupled to the input of the main amplifier device for providing a first radio frequency signal to be amplified by said first amplifier device; and -- a second output coupled to the input of the second amplifier device for providing a second radio frequency signal to be amplified by said second amplifier device; - wherein said signal processing circuit comprises a non-linear processing section (31; 41) coupled to the input of the signal processing circuit and adapted to provide at least said second radio frequency signal with a signal envelope that has a non-linear dependency (f) from an amplitude characteristic of the input signal (In); wherein - the non-linear processing section (31; 41) is adapted such that the degree of non-linearity of the non-linear dependency (f) varies dependent on the amount of change per time unit of the amplitude characteristic of the input signal (In).