Method and apparatus for providing a supply voltage based on an envelope of a radio frequency signal

The present invention relates generally to wireless communication devices and in particular to a wideband envelope tracking amplification system of a wireless communication device. An envelope tracking amplification system that includes an envelope tracking power supply (ETPS) amplifies a radio frequency (RF) signal to produce a linearized amplified signal. The envelope tracking amplification system samples the RF signal to produce a sampled RF signal. The ETPS produces a control signal based on an instantaneous magnitude of the sampled RF signal and further based on an average magnitude of the sampled RF signal, produces multiple supply voltages, and, based on the control signal, couples a supply voltage of the multiple supply voltages to an output of the EPTS to produce an output supply voltage. The envelope tracking amplification system then amplifies the RF signal based on the output supply voltage to produce a highly linear amplified signal.