G. Gong, H. Ertl, J.W. Kolar:
"A Multi-Cell Cascaded Power Amplifier";
Talk: Annual IEEE Applied Power Electronics Conference and Exposition, Dallas, Texas, USA; 03-19-2006 - 03-23-2006; in: "Proceedings of the Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition", (2006), ISBN: 0-7803-9547-6; 1550 - 1556.

A multi-cell cascaded power amplifier with a high
output voltage capability, wide load range and high bandwidth is
presented in this paper. The cascaded power amplifier is formed
by combining a low-voltage linear power amplifier in series with
multiple inverter cells. Therefore the cascaded power amplifier
combines the advantages of a linear power amplifier with the
advantages of a switched mode power amplifier. A high output
voltage and bandwidth of 20kHz is achievable using very simple
modulation and feedback control design. The dc voltages for the
inverter cells and linear power amplifier are provided by an
isolated, bidirectional dc-dc resonant converter. The dimensioning
and physical structure of a 1.2kW, ±400V cascaded amplifier is
given, and shows that a compact, flat system design is possible.
Finally, digital simulation results verify the theoretical analysis of
the amplifier.

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