Patent ID: 9543911
Date: 2017-01-10
CPC Classifications: H01P,H03F,H03G,H03H

Claim:
1. An apparatus comprising: an outphasing amplifier comprising a first amplifier and a second amplifier; and a circulator having a first port coupled to an output of the outphasing amplifier, a second port coupled to a load and a third port coupled to a phase shifter, wherein the phase shifter is configured, responsive to a control signal, to provide a different phase angle of a reflected signal from the phase shifter to the outphasing amplifier through the circulator, wherein the different phase angle is generated based upon a maximum efficiency envelope curve, wherein the maximum efficiency curve is formed by connecting maximum efficiency values of a group of curves, and wherein the group of curves include a first curve and second curve, and wherein the first curve is a curve of efficiency versus power when the load is a resistor and the second curve is a curve of efficiency versus power at a particular phase angle provided by the phase shifter.