Patent ID: 9118277
Filing Date: 2015-08-25
Classification: H03F,H04B

Abstract:
1. An envelope tracker for supplying power to a power amplifier that amplifies a radio frequency (RF) signal, the envelope tracker comprising: an output configured to generate a power amplifier supply voltage; a digital control circuit configured to generate a plurality of control signals based on a digital envelope signal corresponding to a digital representation of an envelope of the RF signal; a buck converter including an output electrically connected to the output of the envelope tracker, the plurality of control signals configured to control one or more switches of the buck converter; a push digital-to-analog converter (DAC) including an output electrically connected to the output of the envelope tracker, the plurality of control signals further configured to control a magnitude of a first current generated at the output of the push DAC; and a pull DAC including an output electrically connected to the output of the envelope tracker, the plurality of control signals further configured to control a magnitude of a second current generated at the output of the pull DAC, the plurality of control signals configured to control the buck converter to track low frequency components of the digital envelope signal, and to control the push DAC and the pull DAC to track high frequency components of the digital envelope signal.