TR2019-041

A Novel 1.4 to 4.8 GHz Ultra Wideband over 45% High Efficiency Digitally Assisted Frequency Periodic Load Modulated Amplifier


    •  Komatsuszaki, Y., Sakata, S., Nakatani, K., Shinjo, S., Ma, R., Benosman, M., Nagai, Y., "A Novel 1.4-4.8 GHz Ultra-Wideband, over 45% High Efficiency Digitally Assisted Frequency-Periodic Load Modulated Amplifier", IEEE International Microwave Symposium (IMS), DOI: 10.1109/MWSYM.2019.8700930, ISSN: 2576-7216, ISBN: 978-1-7281-1309-8, June 2019, pp. 706-709.
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      • @inproceedings{Komatsuszaki2019jun,
      • author = {Komatsuszaki, Yuji and Sakata, Shuichi and Nakatani, Keigo and Shinjo, Shintaro and Ma, Rui and Benosman, Mouhacine and Nagai, Yukimasa},
      • title = {A Novel 1.4-4.8 GHz Ultra-Wideband, over 45% High Efficiency Digitally Assisted Frequency-Periodic Load Modulated Amplifier},
      • booktitle = {IEEE International Microwave Symposium (IMS)},
      • year = 2019,
      • pages = {706--709},
      • month = jun,
      • publisher = {IEEE},
      • doi = {10.1109/MWSYM.2019.8700930},
      • issn = {2576-7216},
      • isbn = {978-1-7281-1309-8},
      • url = {https://www.merl.com/publications/TR2019-041}
      • }
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  • Research Areas:

    Communications, Electronic and Photonic Devices, Signal Processing


We report an ultra-wideband and high efficiency sub-6GHz power amplifier, which is based on periodically varied load modulation with frequency. Key novelties are frequency-periodic load modulation over multiple contiguous frequency bands combined with digitally assisted dual-input configuration, which provides optimum signal combination, magnitude and phase of dual-input signals. The amplifier using 0.15-um GaN HEMT FETs achieved drain efficiency of 45-62% over 1.4-4.8GHz that is 110% fractional bandwidth at 6dB power back-off. This, to the best of the authors’ knowledge, is the widest fractional bandwidth reported so far for a load modulated amplifier at these frequency range. It is a very promising PA technology for 5G base station, enabling reduction of the total cost of ownership (TCO) for operators.