Two-phase buck DC-AC converter as dynamic power supply for amplitude-modulated Class-DE Power Amplifier

This paper presents an analysis of the two-phase buck converter functioning as a dynamic power supply for Class-DE radio-frequency (RF) power amplifier (PA). The equations necessary to design the buck converter providing an ac output voltage with a dc offset is presented. It is shown that the maximum inductor current ripple in the buck converter occurs when the output voltage is at its nominal value. Consequently, the expression for the minimum value of the inductance as a function of efficiency needed for the converter to operate in continuous-conduction mode is derived. Additionally, the necessary equations needed to design the Class-DE RFPA are provided. A design example of a two-phase buck dc-ac converter with Class-DE RFPA as a dynamic load is considered. Simulation results are presented to validate the theoretical results.