Patent ID: 8718579
Filing Date: 2014-05-06
Classification: H03F,H04B

Abstract:
1. A method for time-aligning a supply voltage to a power amplifier in an envelope tracking power amplifier system, the method comprising: generating an envelope tracking signal tracking a detected amplitude of an input signal to the power amplifier; at a first time instance, operating the power supply in a static mode to produce the supply voltage as a substantially constant voltage independent of the envelope tracking signal; at a second time instance, operating the power supply in a dynamic mode to produce the supply voltage as a dynamically varying envelope tracking voltage based on the envelope tracking signal; determining a first delay between the input signal and an output signal of the power amplifier based on portions of the input signal and the output signal captured when the power supply is operating in the static mode; determining a second delay between the input signal and the output signal based on portions of the input signal and the output signal captured when the power supply is operating in the dynamic mode; configuring a delay block to compensate for a determined delay mismatch between the input signal to the power amplifier and the supply voltage, the determined delay mismatch based on a difference between the first delay and the second delay; and amplifying, by a power amplifier, the input signal to generate an output signal, the power amplifier powered from the supply voltage.