Abstract: An apparatus and technique for operating an RF amplifier having a pre-distortion processor and a drain modulation circuit includes generating a compensating drain bias signal having a value which is a function of an RF input signal, a sampled RF output signal and a sampled drain bias signal. The compensating drain bias signal is applied to the RF amplifier. By sampling both the drain bias signal and the RF output signal and providing drain feedback and RF output feedback signals to a pre-distortion processor, RF amplifier distortions can be linearized enabling the RF amplifier to operate over a bandwidth which exceeds the bandwidth of the drain modulation circuit (i.e., the RF bandwidth can exceed the bandwidth of the drain modulator).

Abstract: An apparatus and technique for operating an RF amplifier having a pre-distortion processor and a drain modulation circuit includes generating a compensating drain bias signal having a value which is a function of an RF input signal, a sampled RF output signal and a sampled drain bias signal. The compensating drain bias signal is applied to the RF amplifier. By sampling both the drain bias signal and the RF output signal and providing drain feedback and RF output feedback signals to a pre-distortion processor, RF amplifier distortions can be linearized enabling the RF amplifier to operate over a bandwidth which exceeds the bandwidth of the drain modulation circuit (i.e., the RF bandwidth can exceed the bandwidth of the drain modulator).

Abstract: A power supply stage includes a digital signal generation means to generate n bit digital signal, a selection means for power supply voltages in dependence on n bit digital signal and an adjusting means for receiving the selected power supply voltage and the envelope signal and adapted to generate an adjusted selected power supply voltage tracking the envelope signal.