Amplifier circuitry and method for amplifying a signal using said amplifier circuitry

Abstract

In one aspect the embodiments relate to amplifier circuitry comprising an outphasing region and envelope tracking region. The outphasing region includes a signal processing block capable of receiving an amplitude and phase modulated input signal that is to be amplified, and processing said signal to separate it into two signals (S, S) of constant amplitude and modulated phase, a first signal Sfor driving a first RF power amplifier RF PAand a second signal Sfor driving a second RF power amplifier RF PA. The output signals from each of the RF PAs are then provided to a power combiner (PC) for obtaining an output amplified signal (RF output). The envelope tracking region () includes a linear amplifier (Env Amp) capable of receiving an input representing an envelope of the input signal that to be amplified, a charge storage device Ccoupled to said amplifier for providing an amplified envelope signal for driving the RF PAs, said amplifier () and charge storage device Cbeing arranged to receive a supply voltage V+. The amplifier circuitry is configured such that when the first signal Sand the second signal Sin the outphasing circuitare in phase, an input voltage Vbased on the voltage of the received envelope signal is provided to the amplifier in the envelope tracking region to enable the charge storage device Cto supply a voltage Vabove the supply voltage V+ such that the output voltage of the RF PAs driven by the amplifier () is increased by Vabove the supply voltage V+.