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Archives of Electrical Engineering

The Journal of Polish Academy of Sciences

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A Transformer Class E Amplifier

Miroslaw Mikolajewski
  • Institute of Radioelectronics Faculty of Electronics and Information Technology Warsaw University of Technology ul. Nowowiejska 15/19. 00-665 Warsaw
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Published Online: 2014-12-11 | DOI: https://doi.org/10.2478/aee-2014-0043


In a high-efficiency Class E ZVS resonant amplifier a matching and isolation transformer can replace some or even all inductive components of the amplifier thus simplifying the circuit and reducing its cost. In the paper a theoretical analysis, a design example and its experimental verification for a transformer Class E amplifier are presented. In the experimental amplifier with a transformer as the only inductive component in the circuit high efficiency ηMAX = 0.95 was achieved for supply voltage VI = 36 V, maximum output power POMAX = 100 W and the switching frequency f = 300 kHz. Measured parameters and waveforms showed a good agreement with theoretical predictions. Moreover, the relative bandwidth of the switching frequency was only 19% to obtain output power control from 4.8 W to POMAX with efficiency not less than 0.9 in the regulation range.

Keywords: Class E amplifier; resonant inverter; dc/dc converter; transformer; leakage inductance


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About the article

Received: 2014-08-06

Revised: 2014-09-19

Published Online: 2014-12-11

Citation Information: Archives of Electrical Engineering, Volume 63, Issue 4, Pages 621–633, ISSN (Online) 2300-2506, DOI: https://doi.org/10.2478/aee-2014-0043.

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© 2014 Polish Academy of Sciences. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. BY-NC-ND 3.0

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