A driver circuit for a composite power amplifier comprising first and second sub-amplifiers (111, 112) operating in at least one Chireix-mode for amplification of an input signal into an output signal, wherein the driver circuit for the composite power amplifier is comprising an input network with an input port for receiving the input signal; the input network configured to be connectable to the first and second sub-amplifiers (111, 112) for providing respectively a first feeding signal (IN_1) to the first sub-amplifier and a second feeding signal (IN_2) to the second sub-amplifier; the input network further comprising a means comprising a main splitter for receiving the input signal, first and second gain units (191, 192) for receiving respectively first and second parts of the input signal from the main splitter, wherein the first gain unit is configured to provide: a first signal derived from the input signal, wherein an amplitude of the first signal is linearly derivable from an amplitude of the input signal over an operational amplitude range of the composite power amplifier; and wherein the second gain unit is configured to provide: a second signal derived from the input signal, wherein an amplitude of the second signal is non-linearly derivable from the amplitude of the input signal over the operational amplitude range, and wherein an average rate of amplitude change of the second signal versus amplitude change of the input signal in a first amplitude range is less than an average rate of amplitude change of the second signal versus amplitude change of the input signal in a second amplitude range, a first combiner configured to combine the first signal, at zero degrees phase shift, and the second signal, at 90 degrees phase shift, to obtain the first feeding signal (IN_1) to be fed to the first sub-amplifier, and a second combiner configured to combine the first signal, at 180 degrees phase shift, and the second signal, at 90 degrees phase shift, to obtain the second feeding signal (IN_2) to be fed to the second sub-amplifier, wherein the means comprises a first branch configured to feed the first signal towards the first and second sub-amplifiers (111, 112), wherein the first branch is connected to a first splitter having a first output port and a second output port, wherein the first output port of the first splitter is connected to the first combiner, and wherein the second output port of the first splitter is connected to a first phase shifting element providing the 180 degrees phase shift of the first signal, wherein the means comprises a second branch configured to feed the second signal towards the first and second sub-amplifiers (111, 112), wherein the second branch comprises a second phase shifting element which provides the 90 degrees phase shift of the second signal. a first signal derived from the input signal, wherein an amplitude of the first signal is linearly derivable from an amplitude of the input signal over an operational amplitude range of the composite power amplifier; and wherein the second gain unit is configured to provide: a second signal derived from the input signal, wherein an amplitude of the second signal is non-linearly derivable from the amplitude of the input signal over the operational amplitude range, and wherein an average rate of amplitude change of the second signal versus amplitude change of the input signal in a first amplitude range is less than an average rate of amplitude change of the second signal versus amplitude change of the input signal in a second amplitude range, a first combiner configured to combine the first signal, at zero degrees phase shift, and the second signal, at 90 degrees phase shift, to obtain the first feeding signal (IN_1) to be fed to the first sub-amplifier, and a second combiner configured to combine the first signal, at 180 degrees phase shift, and the second signal, at 90 degrees phase shift, to obtain the second feeding signal (IN_2) to be fed to the second sub-amplifier, wherein the means comprises a first branch configured to feed the first signal towards the first and second sub-amplifiers (111, 112), wherein the first branch is connected to a first splitter having a first output port and a second output port, wherein the first output port of the first splitter is connected to the first combiner, and wherein the second output port of the first splitter is connected to a first phase shifting element providing the 180 degrees phase shift of the first signal, wherein the means comprises a second branch configured to feed the second signal towards the first and second sub-amplifiers (111, 112), wherein the second branch comprises a second phase shifting element which provides the 90 degrees phase shift of the second signal.