Patent ID: 9571152
Date: 2017-02-14
CPC Classifications: H03F,H03G,H04B,H04W

Claim:
1. A power amplifier system comprising: a variable gain amplifier configured to amplify a radio frequency input signal to generate an amplified radio frequency input signal, the variable gain amplifier having a variable gain that is controllable by a gain control level signal; a power amplifier configured to amplify the amplified radio frequency input signal to generate a radio frequency output signal, the power amplifier configured to receive power from a supply voltage; and an envelope tracker configured to generate the supply voltage, the envelope tracker including a scaling module configured to generate a scaled envelope signal based on a power control level signal and an envelope signal that changes in relation to an envelope of the radio frequency input signal, the envelope tracker further including a calibration module configured to control an amount of scaling of the scaled envelope signal based on calibration data to compensate for an envelope amplitude misalignment of the envelope tracker, the envelope tracker further configured to control a voltage level of the supply voltage based on the scaled envelope signal.