A supply modulator with fast mode transition for RF power amplifier

This paper describes a supply modulator for RF power amplifier capable of average-power-tracking (APT) mode and envelope-tracking (ET) mode. The supply modulator uses single controller and switched power stage for both modes and realizes short transitions of less than 10 μs, a required feature for air interface standards specified by 3GPP, such as LTE and 5G. Furthermore, the integrator-less controller minimizes order of the control system and accelerates transitions during APT mode.