PROSPECTS FOR COMBINING HIGHLY EFFICIENT POWER AMPLIFICATION METHODS FOR VHF DIGITAL BROADCASTING TRANSMITTERS

S. E. Grychkin,
Institute of Radio and Information Systems (IRIS), Vienna, Austria;
Moscow Technical University of Communications and Informatics, Moscow, Russia;
sg@radiotest-mtuci.ru

O. V. Varlamov,
Institute of Radio and Information Systems (IRIS), Vienna, Austria;
Moscow Technical University of Communications and Informatics, Moscow, Russia;
vov@mtuci.ru

DOI: 10.36724/2664-066X-2025-11-1-27-33

SYNCHROINFO JOURNAL. Volume 11, Number 1 (2025). P. 27-33.

Abstract

High-efficiency VHF power amplifiers are needed for the successful development of digital radio broadcasting worldwide. To ensure high efficiency when amplifying digital radio broadcasting signals with a high peak factor, it is promising to use switching operating modes of active elements and synthetic amplification methods. An original classification of combining synthetic methods of linear amplification is proposed. It is shown that the most promising method for highly efficient amplification of radio signals with a high peak factor can be considered a power amplifier with Envelope Elimination and Restoration (EER – or Kahn method) with supply voltage quantization in the PWM amplifier of envelope path. Directions for further research are formulated, which include refining the analytical method for power losses calculating of a multilevel PWM amplifier on GaN field-effect transistors, as well as optimizing the number of levels and their values to obtain the highest possible efficiency, taking into account the statistics of the amplified signal.

Keywords:  envelope elimination and restoration; envelope PWM amplifier; high efficiency power amplifier; supply voltage quantization; transmitters; VHF digital radio broadcasting

References

[1] Coverage of the DAB network of countries of the world. URL: https://www.worlddab.org/countries (date of access: 10.02.2025).

[2] A.V. Dvorkovich, V.P. Dvorkovich, V.A. Irtyuga, and K.S. Mityagin, “Field Tests of Digital Terrestrial Multimedia Broadcasting System RAVIS,” 2018 Engineering and Telecommunication (EnT-MIPT), Moscow, Russia, 2018, pp. 3-7, doi: 10.1109/EnT-MIPT.2018.00008.

[3] O.V. Varlamov, “DRM digital broadcasting system audio path qualitative characteristics,” Synchroinfo Journal. 2022. Vol. 8, no. 4. P. 2-8. DOI: 10.36724/2664-066X-2022-8-4-2-8.

[4] O. Varlamov, V. Varlamov and A. Dolgopyatova, “Digital Radio Broadcasting Network in the Arctic Region,” 2019 24th Conference of Open Innovations Association (FRUCT), Moscow, Russia, 2019, pp. 457-462. DOI: 10.23919/FRUCT.2019.8711933.

[5] A.V. Dolgopyatova and O.V. Varlamov, “Analysis of Long-Range VHF Radio Waves Propagation to Specify Protection Ratios Between Coexisting DRM+, RAVIS and IBOC Systems,” 2021 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO, 2021, pp. 1-4, doi: 10.1109/SYNCHROINFO51390.2021.9488392.

[6] O.V. Varlamov DRM digital radio broadcasting technology for creating global coverage network. Vienna: IRIS, 2023. 245 p. ISBN: 978-3-9504882-0-3.

[7] O.V. Varlamov and V.N. Gromorushkin, “High Efficiency Power Amplifier for IoT Applications: RF Path,” 2020 Systems of Signals Generating and Processing in the Field of on Board Communications, Moscow, Russia, 2020, pp. 1-5, doi: 10.1109/IEEECONF48371.2020.9078651.

[8] V.B. Kozyrev, V.G. Lavrushenkov, V.P. Leonov, G.V. Novikov, N.B. Petyashin, I.A. Popov, A.V. Kharitonov, V.N. Gromorushkin, (1985). Transistor harmonic oscillators in switch mode. Moscow: Radio and communication.

[9] N.O. Sokal, “RF power amplifiers, classes A through S-how they operate, and when to use each,” Professional Program Proceedings. Electronic Industries Forum of New England, Boston, MA, USA: 1997. P. 179-252.

[10] Andrei Grebennikov, Marc J. Franco, “Switchmode RF and Microwave Power Amplifiers,” London, England: Academic Press, 2021. 828 p. ISBN 978-0-12-821448-0.

[11] O.V. Varlamov, and V.N. Gromorushkin, “Class D Switching Power Amplifier with a Filter under Load Mismatch Conditions,” 2020 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF), Saint-Petersburg, Russia, 2020, pp. 1-6, doi: 10.1109/WECONF48837.2020.9131508.

[12] O.V. Varlamov, “Intermodulation distortion in voltage mode class D switching amplifiers with resistive load”, T-Comm, 2022. vol. 16, no.10, pp. 4-11. DOI: 10.36724/2072-8735-2022-16-10-4-11.

[13] F. Raab, “Efficiency of Outphasing RF Power-Amplifier Systems,” in IEEE Transactions on Communications, vol. 33, no. 10, pp. 1094-1099, October 1985, doi: 10.1109/TCOM.1985.1096219.

[14] Yu Zhao, M. Iwamoto, L. E. Larson and P. M. Asbeck, “Doherty amplifier with DSP control to improve performance in CDMA operation,” IEEE MTT-S International Microwave Symposium Digest, 2003, Philadelphia, PA, USA, 2003, pp. 687-690 vol.2, doi: 10.1109/MWSYM.2003.1212465.

[15] L. R. Kahn, “Single-Sideband Transmission by Envelope Elimination and Restoration,” in Proceedings of the IRE, vol. 40, no. 7, pp. 803-806, July 1952, doi: 10.1109/JRPROC.1952.273844.

[16] O. Varlamov, D. C. Nguyen, and A. Grebennikov, “Broadband and Efficient Envelope Amplifier for Envelope Elimination and Restoration/Envelope Tracking Higher-Efficiency Power Amplifiers”, Sensors, vol. 22, no. 23, p. 9173, Nov. 2022. DOI: 10.3390/s22239173.

[17] O.V. Varlamov, D.C. Nguyen, S.E. Grychkin, “Combination of synthetic high-performance RF amplification techniques,” T-Comm, vol. 15, no.9, pр. 11-16, 2021. DOI: 10.36724/2072-8735-2021-15-9-11-16.

[18] O.V. Varlamov, “The Technology of Creating a Digital Broadcasting Network of the DRM Standard for the Russian Federation”, D.Sc. Thesis, MTUCI, Moscow, Russia, 2017.

[19] S7HP NEO. Medium wave radio transmitter / Product brochure – S7HP Neo. URL: https://thomsonbroadcast.tv/wp-content/uploads/2021/10/S7HPNEOEN_RVB-compresse.pdf (accessed 10/25/2024).

[20] O.V. Varlamov, “Development of high-efficiency modulation path for HF power amplifier with envelope elimination and restoration”, T-Comm, vol. 5, no. 9, pp. 45-46, 2011.

[21] O.V. Varlamov, “Multiphase PWM characteristics in the EER transmitter envelope path,” 2021 International Conference on Engineering Management of Communication and Technology (EMCTECH), 2021, pp. 1-5, doi: 10.1109/EMCTECH53459.2021.9619166.

[22] A.O. Bolotov, R.G. Kholyukov, and O.V. Varlamov, “EER power amplifier modulator efficiency improvement using PWM with additional sigma-delta modulation,” 2018 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO), Minsk, 2018, pp. 1-4. DOI: 10.1109/SYNCHROINFO.2018.8456955.

[23] J. Rodríguez, J. R. García-Meré, D. G. Aller and J. Sebastián, “Pulsewidth Modulated Three-Level Buck Converter Based on Stacking Switch-Cells for High Power Envelope Tracking Applications,” in IEEE Transactions on Power Electronics, vol. 37, no. 5, pp. 5786-5800, May 2022, doi: 10.1109/TPEL.2021.3131215.

[24] S.E. Grychkin, A.M. Zakharov, O.V. Varlamov, “Method for calculating the efficiency of a PWM modulator based on GaN FET transistors”, T-Comm, 2023. vol. 17, no.9, pp. 19-27. DOI: 10.36724/2072-8735-2023-17-9-19-27.