amplifier incorporated herein by reference to stabilize the linearity performance of the amplifier the temperature of the amplifier is monitored by the temperature sensor and then the gate bias of the amplifier is controlled by the fpga based digital part the feedback portion comprises a directional coupler a mixer a low pass filter lpf gain amplifiers and a band pass filter bpf detectors dets depending upon the embodiment these analog components can be mixed and matched with other analog components part of the rf output signal of the amplifier is sampled by the directional coupler and then down converted to an if analog signal by the local oscillation signal in the mixer the if analog signal is passing through the lpf the gain amplifier and the bpf e g surface acoustic wave filter which can capture different frequency portions of out of band distortions the output of the bpf is provided to the detector and then to the adcs of the fpga based digital module in order to determine the dynamic parameters of the pd depending on output power levels and asymmetrical distortions due to the memory effects in addition temperature is also detected by the det 580 to calculate the variation of linearity and then adjust gate bias voltage of the pa more details of the pd algorithm and self adaptation feedback algorithm can be appreciated from fig3 which shows a polynomial based predistortion algorithm and from fig4 which shows in flow diagram form as steps 401 through.