Patent ID: 7091790

Claim:
A power amplifier (PA) circuit comprising: a PA output stage having a first amplifying portion having a first amplification and disposed in parallel with a second amplifying portion having a second amplification portion, the PA output stage having an output stage input port for receiving of a RF input signal, an output stage output port for providing of an amplified RF signal, and an output stage amplification being the amplification from the output stage input port to the output stage output port; at least a biasing circuit for biasing of at least one of the first amplifying portion and the second amplifying portion; a DC to DC converter circuit coupled with the second amplifying portion for providing of a second converted output voltage to the second amplifying portion; a first control port coupled with the DC to DC converter and for receiving a first control signal to control the DC to DC converter second converted output voltage in dependence upon a predetermined signal strength of the amplified RF signal at the output stage output port; and, a second control port coupled with the at least a biasing circuit and for receiving a second control signal to control the at least a biasing circuit in such a manner that a ratio of RF input signal amplification between the first amplification and the second amplification varies in dependence upon the predetermined signal strength at the output stage output port.