Patent ID: 9692366
Date: 2017-06-27
CPC Classifications: H03F,H04B

Claim:
1. An envelope tracking system, comprising: a transmitter configured to generate an output signal; an envelope tracking path configured to adaptively generate a supply voltage that varies based on an instantaneous envelope signal derived from an input signal; a signal processing path configured to generate a converted signal via a signal conversion of the input signal and provide the converted signal to a power amplifier; a delay component configured to generate a first delay of the envelope tracking path with respect to a second delay of the signal processing path, the first delay being tunable and based on a feedback signal of a feedback path that is derived from the output signal; a calibration component, operatively coupled to a cross-correlation component and the signal processing path downstream of the envelope tracking path branching from the signal processing path, configured to generate an in-band calibration signal based on the input signal and provide the in-band calibration signal to the cross-correlation component and to the signal processing path at a point downstream after the envelope tracking path branches from the signal processing path to isolate the in-band calibration signal from being received in the envelope tracking path; and the cross-correlation component, operatively coupled to a calibration path from the calibration component and the feedback path, configured to receive the in-band calibration signal from the calibration component separate from the input signal that is at the signal processing path and concurrent with the signal processing path processing the input signal, and perform a cross-correlation function of the in-band calibration signal received from the calibration path and the feedback signal received from the feedback path by identifying similar portions of the in-band calibration signal and the feedback signal.