A power supply apparatus for a power amplifier includes a converter configured to convert input power into driving power for the power amplifier, a detector configured to transfer the driving power from the converter to the power amplifier, including an inductor formed on a detection path of the driving power, and configured to detect power information regarding the driving power to generate a detected signal, and a controller configured to control power conversion of the converter based on an envelope signal of a signal input to the power amplifier and the detected signal.