Patent ID: 9621111
Date: 2017-04-11
CPC Classifications: H03F,H03G,H04B

Claim:
1. A power amplifier system comprising: a power amplifier configured to amplify a radio frequency signal to generate an amplified radio frequency signal; an envelope tracker configured to generate a power amplifier supply voltage of the power amplifier and to control a voltage level of the power amplifier supply voltage based on a shaped envelope signal; an envelope shaping circuit configured to use a shaping table calibrated at a first radio frequency power level to generate the shaped envelope signal according to an envelope of the radio frequency signal, the shaping table configured to maintain a substantially constant distortion in at least one of a transmit band or a receive band across voltage changes in the envelope of the radio frequency signal; and a gain control circuit configured to enhance a combined power efficiency of the power amplifier and a modulator used to generate the radio frequency signal.