CPC H03F 1/0227 (2013.01) [H03F 3/195 (2013.01); H03F 3/245 (2013.01); H03F 2200/102 (2013.01); H03F 2200/168 (2013.01); H03F 2200/336 (2013.01); H03F 2200/451 (2013.01)] | 20 Claims |
1. An envelope tracking system comprising:
a power amplifier configured to amplify a radio frequency signal and to receive power from a power amplifier supply voltage; and
an envelope tracker configured to generate the power amplifier supply voltage at an envelope tracker output based on an analog envelope signal corresponding to an envelope of the radio frequency signal, the envelope tracker including a plurality of modulators each receiving a plurality of regulated voltages, a plurality of modulator output filters each coupled between the envelope tracker output and a corresponding one of the plurality of modulators, and a modulator control circuit configured to control the plurality of modulators based on the analog envelope signal.
|