CPC H03F 3/245 (2013.01) [H04B 1/40 (2013.01); H04W 52/52 (2013.01); H03F 2200/105 (2013.01); H03F 2200/451 (2013.01)] | 20 Claims |
1. An envelope tracking system comprising:
a power amplifier configured to amplify a radio frequency transmit signal, the power amplifier powered by a power amplifier supply voltage; and
an envelope tracker configured to generate the power amplifier supply voltage based on an envelope signal indicating an envelope of the radio frequency transmit signal, the envelope tracker including an amplifier input stage configured to generate a control current and a sense current based on the envelope signal, an amplifier output stage configured to adjust the power amplifier supply voltage based on the control current, and a modulator configured to adjust a supply voltage of the amplifier output stage based on the sense current.
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