Abstract: A symbol-power-tracking (SPT) voltage supply to power a radio-frequency power amplifier (RF PA) is shown. A power converter is coupled to an output port of an input power source for power conversion, and has an output terminal coupled to a power terminal of the RF PA. A transition capacitor is coupled to the power terminal of the radio-frequency power amplifier through the output terminal of the power converter. An assisted charging and discharging circuit is coupled to the transition capacitor during cyclic prefix (CP) sections. A multi-level array is provided which includes a plurality of voltage-regulated capacitors pre-charged to and kept at different voltage levels. During each symbol section, a target capacitor at a fixed voltage level matching the current SPT situation is selected from among the voltage-regulated capacitors to be coupled to the power terminal of the radio-frequency power amplifier.