A cascaded multilevel class-D power amplifier output harmonic

A novel switch-mode power amplifier based on a cascaded multicell multilevel circuit topology is introduced in the paper. By application of the concept of multicell topology being operated in a unipolar phase-shifted PWM control to switch-mode amplifier system, the effective switching of output results in 2N times the switching frequency of each full-bridge. Due to the Carrier-Based phase-shifted modulation of the individual switching cells, the output voltage ripple of the total system is considerably small. The paper analyzes the advanced characteristic of the cascaded multilevel technique. A multilevel class-D amplifier´s output harmonic with vary modulation index M is analyzed and then a cascaded multilevel class-D power amplifier is built in the laboratory. The result of measurement shows an good following performance and stability.