US Patent 11165514 Envelope alignment calibration in radio frequency systems

Apparatus and methods for envelope alignment calibration in radio frequency (RF) systems are provided. In certain embodiments, calibration is performed by providing an envelope signal with a peak along an envelope path, and by providing an RF signal with a first peak and a second peak to a power amplifier along an RF signal path. Additionally, an output of the power amplifier is observed to generate an observation signal using an observation receiver. The observation signal includes a first peak and a second peak corresponding to the first peak and the second peak of the RF signal, and a delay between the envelope signal and the RF signal is controlled based on relative size of the peaks of the observation signal to one another.