Patent ID: 9054651
Filing Date: 2015-06-09
Classification: H03F

Abstract:
1. A power amplifier circuit, comprising: a final stage, comprising first and second amplifying elements for amplifying an input signal; a driver stage, for providing the input signal to the final stage, characterized by a first capacitor coupled between an input of the first amplifying element and an output of the second amplifying element; and a second capacitor coupled between an input of the second amplifying element and an output of the first amplifying element; wherein the final stage is configured to apply a first phase-shift transfer characteristic to the input signal, and wherein the driver stage is configured to apply a second phase-shift transfer characteristic to the input signal, such that the first and second phase-shift transfer characteristics combine to at least partially cancel each other over a range of input signal values; and wherein the first phase-shift transfer characteristic applies a zero phase shift at relatively low input signal values, and a positive phase shift at relatively high input signal values, and wherein the second phase-shift transfer characteristic applies a zero phase shift at relatively low input signal values, and a negative phase shift at relatively high input signal values.