Patent ID: 8909175

Claim:
A method of operating an RF transmitter utilizing a linear, envelope-tracking, RF power amplifier having an output which receives a biasing signal and having an input, said method comprising: forming a deeper-trough envelope tracking signal for a baseband communication signal, said deeper-trough envelope tracking signal exhibiting peaks and troughs wherein at least a portion of said troughs are deeper than corresponding troughs in a shallower-trough envelope tracking signal; forming a trough-filling signal from said deeper-trough envelope tracking signal, said trough-filling signal being configured to isolate said portion of said troughs; combining said trough-filling signal with said deeper-trough envelope tracking signal to detrough said deeper-trough envelope tracking signal and form said shallower-trough envelope tracking signal; biasing said output of said RF power amplifier in response to said shallower-trough envelope tracking signal; and driving said input of said RF power amplifier with an RF communication signal formed in response to said baseband communication signal.