The analyzing of a cascaded multilevel class-D power amplifier with the carrier-based phase-shifted modulation

This paper presents a switch-mode power amplifier based on a cascaded multicell multilevel circuit topology. Amplifiers based on the single-phase inverter topology or H-bridge is most easily accomplished by the direct series, or parallel, connection of multiple H-bridge power-stages. Operating these with the phase-shifted PWM control gives higher output power and produces an improved output voltage spectrum and significantly lowers output current-ripple. Two carrier-based PWM schemes, phase-shifted and level-shifted modulations, are analyzed and their performance is compared. A multilevel class-D amplifier´s mathematic model is analyzed. The results of measurements taken from a laboratory setup are presented which prove the proposed amplifier improves the dynamic system behavior and have wide bandwidth.