Efficiency for linear amplifier of envelope tracking modulator

摘要

There is disclosed an envelope tracking power supply arranged to generate a modulated supply voltage in dependence on a reference signal, comprising a first path for tracking low frequency variations in the reference signal and a second path for tracking high frequency variations in the reference signal, the second path including a linear amplifier, wherein the output of the linear amplifier comprises a current source and a current sink connected to the high frequency output, there further being provided a DC offset current at the high frequency output.

主权项

1. An envelope tracking power supply arranged to generate a modulated supply voltage in dependence on a reference signal, comprising:
a first path for tracking low frequency variations in the reference signal; and a second path for tracking high frequency variations in the reference signal, wherein the second path comprises:
a linear amplifier having an output stage coupled to an output node, wherein the output stage comprises a current source and a current sink, wherein the current source is coupled between the output node and a first voltage supply and the current sink is coupled between the output node and electrical ground;a switch mode converter configured to generate a second voltage supply to generate a DC offset current based on a power difference between a power associated with the current sink and a power associated with the current source; andan inductor, coupled between the second voltage supply and the output node, for providing the DC offset current at the output node.