Phase-modulated load apparatus and method

摘要

Methods and apparatus are provided to improve the efficiency of an outphasing amplifier through modulating the phase angle of a reflected signal in the outphasing amplifier. An outphasing amplifier includes a first amplifier and a second amplifier. A circulator is provided 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. The phase shifter is configured to provide a different phase angle of a reflected signal from the phase shifter to the outphasing amplifier through the circulator.

主权项

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.