An apparatus and method for a Time Alignment (TA) operation used by an Envelope Tracking (ET) Radio Frequency (RF) Power Amplifier (PA) that amplifies RF signals are provided. The ET RF PA has an input signal including complex, reference, and feedback signals. The apparatus includes a fast convolution unit for receiving the reference signal and the feedback signal, fore extracting respective envelopes of the reference signal and the feedback signal, for generating a cross-covariance vector for the reference signal envelope and the feedback signal envelope, a delay estimation unit for receiving the cross-covariance vector from the fast convolution unit, for determining peak values of the cross-covariance vector, for performing a fine time delay estimation, and for generating time delay settings according to the fine time delay estimation, and delay filters respectively delaying a timing of the reference signal and the feedback signal according to the generated time delay settings.