Review of High RF Power Amplifier for 5G Applications

[1] M. J. Ayoub, M. Alloush, A. Mohsen, A. Harb, N. Deltimple, and A. Serhane, “Class ab vs. class j 5G power amplifier in 28-nm UTBB FD-SOI technology for high efficiency operation,” in 2017 29th International Conference on Microelectronics (ICM), IEEE, 2017, pp. 1–4, doi: 10.1109/ICM.2017.8268876.

[2] P. Reynaert and M. Steyaert, RF power amplifiers for mobile communications. Springer Science & Business Media, 2006,ISBN: 1-4020-5117-4.

[3] A. M. Niknejad, S. Thyagarajan, E. Alon, Y. Wang, and C. Hull, “A circuit designer’s guide to 5G mm-wave,” in 2015 IEEE Custom Integrated Circuits Conference (CICC), IEEE, 2015, pp. 1–8, doi: 10.1109/CICC.2015.7338410.

[4] M. Agiwal, A. Roy, and N. Saxena, “Next generation 5G wireless networks: A comprehensive survey,” IEEE Communications Surveys & Tutorials, vol. 18, no. 3, pp. 1617–1655, 2016, doi: 10.1109/COMST.2016.2532458.

[5] D. Y. Lie, J. C. Mayeda, Y. Li, and J. Lopez, “A review of 5G power amplifier design at cm-wave and mm-wave frequencies,” Wireless Communications

and Mobile Computing, vol. 2018, 2018, https://doi.org/10.1155/2018/6793814

[6] J. A. Jayamon, J. F. Buckwalter, and P. M. Asbeck, “28 GHz> 250 mW CMOS power amplifier using multigate-cell design,” in 2015 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS), IEEE, 2015, pp. 1–4, doi:10.1109/CSICS.2015.7314460.

[7] Y.-H. Chen, K.-Y. Kao, C.-Y. Chao, and K.-Y. Lin, “A 24 GHz CMOS power amplifier with successive IM2 feed-forward IMD3 cancellation,” in 2015 IEEE MTT-S International Microwave Symposium, IEEE, 2015, pp. 1–4, doi: 10.1109/MWSYM.2015.7166914.

[8] K. Kunihiro, S. Hori, and T. Kaneko, “High efficiency power amplifiers for mobile base stations: Recent trends and future prospects for 5G,” IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences, vol. 101, no. 2, pp. 374–384, 2018, doi: https://doi.org/10.1587/transfun.E101.A.374.

[9] C. Nadjahi, H. Louahlia, and S. Lemasson, “A review of thermal management and innovative cooling strategies for data center,” Sustainable Computing: Informatics and Systems, vol. 19, pp. 14–28, 2018, doi: https://doi.org/10.1016/j.suscom.2018.05.002.

[10]        R. Dar, M. Feder, A. Mecozzi, and M. Shtaif, “Inter-channel nonlinear interference noise in WDM systems: modeling and mitigation,” Journal of Lightwave Technology, vol. 33, no. 5, pp. 1044–1053, 2014. https://doi.org/10.1155/2018/6793814.

[11]        Z. Tong, L. Gu, Z. Ye, K. Surakitbovorn, and J. Rivas-Davila, “On the techniques to utilize SiC power devices in high-and very high-frequency power converters,” IEEE Transactions on Power Electronics, vol. 34, no. 12, pp. 12181–12192, 2019. doi:10.1109/TPEL.2019.2904591.

[12]        K. H. Hamza and D. Nirmal, “A review of GaN HEMT broadband power amplifiers,” AEU-International Journal of Electronics and Communications, vol. 116, p. 153040, 2020, doi: https://doi.org/10.1016/j.aeue.2019.153040.

[13]        C. Huang, S. He, and F. You, “Design of broadband modified class-J Doherty power amplifier with specific second harmonic terminations,” IEEE Access, vol. 6, pp. 2531–2540, 2017, doi: 10.1109/ACCESS.2017.2784094.

[14]        F. Wang, A. H. Yang, D. F. Kimball, L. E. Larson, and P. M. Asbeck, “Design of wide-bandwidth envelope-tracking power amplifiers for OFDM applications,” IEEE Transactions on Microwave theory and techniques, vol. 53, no. 4, pp. 1244–1255, 2005, doi:10.1109/TMTT.2005.845716.

[15]        D. Cox, “Linear amplification with nonlinear components,” IEEE transactions on Communications, vol. 22, no. 12, pp. 1942–1945, 1974, doi:10.1109/TCOM.1974.1092141.

[16]        F. Wang et al., “An improved power-added efficiency 19-dBm hybrid envelope elimination and restoration power amplifier for 802.11 g WLAN applications,” IEEE Transactions on Microwave Theory and Techniques, vol. 54, no. 12, pp. 4086–4099, 2006, doi: 10.1109/TMTT.2006.885575.

[17]        W. H. Doherty, “A new high efficiency power amplifier for modulated waves,” Proceedings of the Institute of radio engineers, vol. 24, no. 9, pp. 1163–1182, 1936, doi: 10.1109/JRPROC.1936.228468.

[18]        C. Ramella, A. Piacibello, R. Quaglia, V. Camarchia, and M. Pirola, “High efficiency power amplifiers for modern mobile communications: The load-modulation approach,” Electronics, vol. 6, no. 4, p. 96, 2017, doi.org/10.3390/electronics6040096.

[19]        A. Nasri et al., “Broadband Class-J GaN Doherty Power Amplifier,” Electronics, vol. 11, no. 4, p. 552, 2022, doi: https://doi.org/10.3390/electronics11040552.

[20]        S. Z. Asif, "5G Mobile Communications Concepts and Technologies", CRC Press, 2018, doi: https://doi.org/10.1201/9780429466342

[21]        X. H. Fang and K.-K. M. Cheng, “Extension of high-efficiency range of Doherty amplifier by using complex combining load,” IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 9, pp. 2038–2047, 2014, doi: 10.1109/TMTT.2014.2333713.

[22]        M. Özen, K. Andersson, and C. Fager, “Symmetrical Doherty power amplifier with extended efficiency range,” IEEE Transactions on Microwave Theory and Techniques, vol. 64, no. 4, pp. 1273–1284, 2016, doi: 10.1109/TMTT.2016.2529601.

[23]        X.-H. Fang, H.-Y. Liu, and K.-K. M. Cheng, “Extended efficiency range, equal-cell Doherty amplifier design using explicit circuit model,” IEEE Microwave and Wireless Components Letters, vol. 27, no. 5, pp. 497–499, 2017, doi: 10.1109/LMWC.2017.2690870.

[24]        W. Shi, S. He, and N. Gideon, “Extending high‐efficiency power range of symmetrical Doherty power amplifiers by taking advantage of peaking stage,” IET Microwaves, Antennas & Propagation, vol. 11, no. 9, pp. 1296–1302, 2017, doi: https://doi.org/10.1049/iet-map.2017.0119.

[25]        M. R. Hasin and J. Kitchen, “Exploiting phase for extended efficiency range in symmetrical Doherty power amplifiers,” IEEE Transactions on Microwave Theory and Techniques, vol. 67, no. 8, pp. 3455–3463, 2019, doi: 10.1109/TMTT.2019.2921366.

[26]        X.-H. Fang, H.-Y. Liu, K.-K. M. Cheng, and S. Boumaiza, “Two-way Doherty power amplifier efficiency enhancement by incorporating transistors’ nonlinear phase distortion,” IEEE Microwave and Wireless Components Letters, vol. 28, no. 2, pp. 168–170, 2018, doi: 10.1109/LMWC.2017.2783845.

[27]        M. R. Hasin and J. Kitchen, “Optimized load trajectory for finite peaking off-state impedance-based Doherty power amplifiers,” IEEE Microwave and Wireless Components Letters, vol. 29, no. 7, pp. 486–488, 2019, doi: 10.1109/LMWC.2019.2915998.

[28]        Z. Cheng, G. Xiong, Y. Liu, T. Zhang, J. Tian, and Y. J. Guo, “High-efficiency Doherty power amplifier with wide OPBO range for base station systems,” IET Microwaves, Antennas & Propagation, vol. 13, no. 7, pp. 926–929, 2019, doi.org/10.1049/iet-map.2018.5617.

[29]        Z. Zhang, Z. Cheng, and G. Liu, “A power amplifier with large high-efficiency range for 5G communication,” Sensors, vol. 20, no. 19, p. 5581, 2020, doi:  10.3390/s20195581.

[30]        W. Yimin, C. Jiayi, and L. Jiawang, “Design of Sub-6G 150W High Efficiency Doherty Power Amplifier,” in 2021 International Applied Computational Electromagnetics Society (ACES-China) Symposium, IEEE, 2021, pp. 1–2, doi: 10.23919/ACES-China52398.2021.9581728.

[31]        N. Sridhar, C. Senthilpari, R. Mardeni, W. H. Yong, and T. Nandhakumar, “A low power, highly efficient, linear, enhanced wideband Class-J mode power amplifier for 5G applications,” Scientific Reports, vol. 12, no. 1, p. 8101, 2022, doi: 10.1038/s41598-022-12235-z.

[32]        M. Dong, “A High Efficiency Class J RF Power Amplifier.,” Microwave Journal, vol. 58, no. 6, 2015, ISSN:0192-6225.

[33]        B. Liu, M. Mao, C. C. Boon, P. Choi, D. Khanna, and E. A. Fitzgerald, “A fully integrated class-J GaN MMIC power amplifier for 5-GHz WLAN 802.11 ax application,” IEEE Microwave and Wireless Components Letters, vol. 28, no. 5, pp. 434–436, 2018, doi: 10.1109/LMWC.2018.2811338.

[34]        M. Sajedin et al., “Energy efficient and wideband class-J Doherty power amplifier,” in 2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP), IEEE, 2020, pp. 1–6, doi: 10.1109/CSNDSP49049.2020.9249642.

[35]        T. Canning, P. J. Tasker, and S. C. Cripps, “Continuous mode power amplifier design using harmonic clipping contours: Theory and practice,” IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 1, pp. 100–110, 2013, doi: 10.1109/TMTT.2013.2292675.

[36]      S. Rezaei, L. Belostotski, F. M. Ghannouchi, and P. Aflaki, “Integrated design of a Class-J power amplifier,” IEEE Transactions on Microwave Theory and Techniques, vol. 61, no. 4, pp. 1639–1648, 2013, , doi: 10.1109/TMTT.2013.2247618

[37]        J. Xia, X. Zhu, L. Zhang, J. Zhai, and Y. Sun, “High-efficiency GaN Doherty power amplifier for 100-MHz LTE-advanced application based on modified load modulation network,” IEEE transactions on microwave theory and techniques, vol. 61, no. 8, pp. 2911–2921, 2013, doi: 10.1109/TMTT.2013.2269052.

[38]        J. Pang, S. He, C. Huang, Z. Dai, J. Peng, and F. You, “A post-matching Doherty power amplifier employing low-order impedance inverters for broadband applications,” IEEE Transactions on Microwave Theory and Techniques, vol. 63, no. 12, pp. 4061–4071, 2015, doi: 10.1109/TMTT.2015.2495201.

[39]        J. Xia, M. Yang, Y. Guo, and A. Zhu, “A broadband high-efficiency Doherty power amplifier with integrated compensating reactance,” IEEE Transactions on Microwave Theory and Techniques, 

[1] M. J. Ayoub, M. Alloush, A. Mohsen, A. Harb, N. Deltimple, and A. Serhane, “Class ab vs. class j 5G power amplifier in 28-nm UTBB FD-SOI technology for high efficiency operation,” in 2017 29th International Conference on Microelectronics (ICM), IEEE, 2017, pp. 1–4, doi: 10.1109/ICM.2017.8268876.

[2] P. Reynaert and M. Steyaert, RF power amplifiers for mobile communications. Springer Science & Business Media, 2006,ISBN: 1-4020-5117-4.

[3] A. M. Niknejad, S. Thyagarajan, E. Alon, Y. Wang, and C. Hull, “A circuit designer’s guide to 5G mm-wave,” in 2015 IEEE Custom Integrated Circuits Conference (CICC), IEEE, 2015, pp. 1–8, doi: 10.1109/CICC.2015.7338410.

[4] M. Agiwal, A. Roy, and N. Saxena, “Next generation 5G wireless networks: A comprehensive survey,” IEEE Communications Surveys & Tutorials, vol. 18, no. 3, pp. 1617–1655, 2016, doi: 10.1109/COMST.2016.2532458.

[5] D. Y. Lie, J. C. Mayeda, Y. Li, and J. Lopez, “A review of 5G power amplifier design at cm-wave and mm-wave frequencies,” Wireless Communications

and Mobile Computing, vol. 2018, 2018, https://doi.org/10.1155/2018/6793814

[6] J. A. Jayamon, J. F. Buckwalter, and P. M. Asbeck, “28 GHz> 250 mW CMOS power amplifier using multigate-cell design,” in 2015 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS), IEEE, 2015, pp. 1–4, doi:10.1109/CSICS.2015.7314460.

[7] Y.-H. Chen, K.-Y. Kao, C.-Y. Chao, and K.-Y. Lin, “A 24 GHz CMOS power amplifier with successive IM2 feed-forward IMD3 cancellation,” in 2015 IEEE MTT-S International Microwave Symposium, IEEE, 2015, pp. 1–4, doi: 10.1109/MWSYM.2015.7166914.

[8] K. Kunihiro, S. Hori, and T. Kaneko, “High efficiency power amplifiers for mobile base stations: Recent trends and future prospects for 5G,” IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences, vol. 101, no. 2, pp. 374–384, 2018, doi: https://doi.org/10.1587/transfun.E101.A.374.

[9] C. Nadjahi, H. Louahlia, and S. Lemasson, “A review of thermal management and innovative cooling strategies for data center,” Sustainable Computing: Informatics and Systems, vol. 19, pp. 14–28, 2018, doi: https://doi.org/10.1016/j.suscom.2018.05.002.

[10]        R. Dar, M. Feder, A. Mecozzi, and M. Shtaif, “Inter-channel nonlinear interference noise in WDM systems: modeling and mitigation,” Journal of Lightwave Technology, vol. 33, no. 5, pp. 1044–1053, 2014. https://doi.org/10.1155/2018/6793814.

[11]        Z. Tong, L. Gu, Z. Ye, K. Surakitbovorn, and J. Rivas-Davila, “On the techniques to utilize SiC power devices in high-and very high-frequency power converters,” IEEE Transactions on Power Electronics, vol. 34, no. 12, pp. 12181–12192, 2019. doi:10.1109/TPEL.2019.2904591.

[12]        K. H. Hamza and D. Nirmal, “A review of GaN HEMT broadband power amplifiers,” AEU-International Journal of Electronics and Communications, vol. 116, p. 153040, 2020, doi: https://doi.org/10.1016/j.aeue.2019.153040.

[13]        C. Huang, S. He, and F. You, “Design of broadband modified class-J Doherty power amplifier with specific second harmonic terminations,” IEEE Access, vol. 6, pp. 2531–2540, 2017, doi: 10.1109/ACCESS.2017.2784094.

[14]        F. Wang, A. H. Yang, D. F. Kimball, L. E. Larson, and P. M. Asbeck, “Design of wide-bandwidth envelope-tracking power amplifiers for OFDM applications,” IEEE Transactions on Microwave theory and techniques, vol. 53, no. 4, pp. 1244–1255, 2005, doi:10.1109/TMTT.2005.845716.

[15]        D. Cox, “Linear amplification with nonlinear components,” IEEE transactions on Communications, vol. 22, no. 12, pp. 1942–1945, 1974, doi:10.1109/TCOM.1974.1092141.

[16]        F. Wang et al., “An improved power-added efficiency 19-dBm hybrid envelope elimination and restoration power amplifier for 802.11 g WLAN applications,” IEEE Transactions on Microwave Theory and Techniques, vol. 54, no. 12, pp. 4086–4099, 2006, doi: 10.1109/TMTT.2006.885575.

[17]        W. H. Doherty, “A new high efficiency power amplifier for modulated waves,” Proceedings of the Institute of radio engineers, vol. 24, no. 9, pp. 1163–1182, 1936, doi: 10.1109/JRPROC.1936.228468.

[18]        C. Ramella, A. Piacibello, R. Quaglia, V. Camarchia, and M. Pirola, “High efficiency power amplifiers for modern mobile communications: The load-modulation approach,” Electronics, vol. 6, no. 4, p. 96, 2017, doi.org/10.3390/electronics6040096.

[19]        A. Nasri et al., “Broadband Class-J GaN Doherty Power Amplifier,” Electronics, vol. 11, no. 4, p. 552, 2022, doi: https://doi.org/10.3390/electronics11040552.

[20]        S. Z. Asif, "5G Mobile Communications Concepts and Technologies", CRC Press, 2018, doi: https://doi.org/10.1201/9780429466342

[21]        X. H. Fang and K.-K. M. Cheng, “Extension of high-efficiency range of Doherty amplifier by using complex combining load,” IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 9, pp. 2038–2047, 2014, doi: 10.1109/TMTT.2014.2333713.

[22]        M. Özen, K. Andersson, and C. Fager, “Symmetrical Doherty power amplifier with extended efficiency range,” IEEE Transactions on Microwave Theory and Techniques, vol. 64, no. 4, pp. 1273–1284, 2016, doi: 10.1109/TMTT.2016.2529601.

[23]        X.-H. Fang, H.-Y. Liu, and K.-K. M. Cheng, “Extended efficiency range, equal-cell Doherty amplifier design using explicit circuit model,” IEEE Microwave and Wireless Components Letters, vol. 27, no. 5, pp. 497–499, 2017, doi: 10.1109/LMWC.2017.2690870.

[24]        W. Shi, S. He, and N. Gideon, “Extending high‐efficiency power range of symmetrical Doherty power amplifiers by taking advantage of peaking stage,” IET Microwaves, Antennas & Propagation, vol. 11, no. 9, pp. 1296–1302, 2017, doi: https://doi.org/10.1049/iet-map.2017.0119.

[25]        M. R. Hasin and J. Kitchen, “Exploiting phase for extended efficiency range in symmetrical Doherty power amplifiers,” IEEE Transactions on Microwave Theory and Techniques, vol. 67, no. 8, pp. 3455–3463, 2019, doi: 10.1109/TMTT.2019.2921366.

[26]        X.-H. Fang, H.-Y. Liu, K.-K. M. Cheng, and S. Boumaiza, “Two-way Doherty power amplifier efficiency enhancement by incorporating transistors’ nonlinear phase distortion,” IEEE Microwave and Wireless Components Letters, vol. 28, no. 2, pp. 168–170, 2018, doi: 10.1109/LMWC.2017.2783845.

[27]        M. R. Hasin and J. Kitchen, “Optimized load trajectory for finite peaking off-state impedance-based Doherty power amplifiers,” IEEE Microwave and Wireless Components Letters, vol. 29, no. 7, pp. 486–488, 2019, doi: 10.1109/LMWC.2019.2915998.

[28]        Z. Cheng, G. Xiong, Y. Liu, T. Zhang, J. Tian, and Y. J. Guo, “High-efficiency Doherty power amplifier with wide OPBO range for base station systems,” IET Microwaves, Antennas & Propagation, vol. 13, no. 7, pp. 926–929, 2019, doi.org/10.1049/iet-map.2018.5617.

[29]        Z. Zhang, Z. Cheng, and G. Liu, “A power amplifier with large high-efficiency range for 5G communication,” Sensors, vol. 20, no. 19, p. 5581, 2020, doi:  10.3390/s20195581.

[30]        W. Yimin, C. Jiayi, and L. Jiawang, “Design of Sub-6G 150W High Efficiency Doherty Power Amplifier,” in 2021 International Applied Computational Electromagnetics Society (ACES-China) Symposium, IEEE, 2021, pp. 1–2, doi: 10.23919/ACES-China52398.2021.9581728.

[31]        N. Sridhar, C. Senthilpari, R. Mardeni, W. H. Yong, and T. Nandhakumar, “A low power, highly efficient, linear, enhanced wideband Class-J mode power amplifier for 5G applications,” Scientific Reports, vol. 12, no. 1, p. 8101, 2022, doi: 10.1038/s41598-022-12235-z.

[32]        M. Dong, “A High Efficiency Class J RF Power Amplifier.,” Microwave Journal, vol. 58, no. 6, 2015, ISSN:0192-6225.

[33]        B. Liu, M. Mao, C. C. Boon, P. Choi, D. Khanna, and E. A. Fitzgerald, “A fully integrated class-J GaN MMIC power amplifier for 5-GHz WLAN 802.11 ax application,” IEEE Microwave and Wireless Components Letters, vol. 28, no. 5, pp. 434–436, 2018, doi: 10.1109/LMWC.2018.2811338.

[34]        M. Sajedin et al., “Energy efficient and wideband class-J Doherty power amplifier,” in 2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP), IEEE, 2020, pp. 1–6, doi: 10.1109/CSNDSP49049.2020.9249642.

[35]        T. Canning, P. J. Tasker, and S. C. Cripps, “Continuous mode power amplifier design using harmonic clipping contours: Theory and practice,” IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 1, pp. 100–110, 2013, doi: 10.1109/TMTT.2013.2292675.

[36]      S. Rezaei, L. Belostotski, F. M. Ghannouchi, and P. Aflaki, “Integrated design of a Class-J power amplifier,” IEEE Transactions on Microwave Theory and Techniques, vol. 61, no. 4, pp. 1639–1648, 2013, , doi: 10.1109/TMTT.2013.2247618

[37]        J. Xia, X. Zhu, L. Zhang, J. Zhai, and Y. Sun, “High-efficiency GaN Doherty power amplifier for 100-MHz LTE-advanced application based on modified load modulation network,” IEEE transactions on microwave theory and techniques, vol. 61, no. 8, pp. 2911–2921, 2013, doi: 10.1109/TMTT.2013.2269052.

[38]        J. Pang, S. He, C. Huang, Z. Dai, J. Peng, and F. You, “A post-matching Doherty power amplifier employing low-order impedance inverters for broadband applications,” IEEE Transactions on Microwave Theory and Techniques, vol. 63, no. 12, pp. 4061–4071, 2015, doi: 10.1109/TMTT.2015.2495201.

[39]        J. Xia, M. Yang, Y. Guo, and A. Zhu, “A broadband high-efficiency Doherty power amplifier with integrated compensating reactance,” IEEE Transactions on Microwave Theory and Techniques, vol. 64, no. 7, pp. 2014–2024, 2016, doi: 10.1109/TMTT.2016.2574861.

 

[40]        G. Sun and R. H. Jansen, “Broadband Doherty power amplifier via real frequency technique,” IEEE Transactions on Microwave Theory and Techniques, vol. 60, no. 1, pp. 99–111, 2011, doi: 10.1109/TMTT.2011.2175237.

[41]        J. M. Rubio, J. Fang, V. Camarchia, R. Quaglia, M. Pirola, and G. Ghione, “3–3.6-GHz wideband GaN Doherty power amplifier exploiting output compensation stages,” IEEE Transactions on Microwave Theory and Techniques, vol. 60, no. 8, pp. 2543–2548, 2012, doi: 10.1109/TMTT.2012.2201745.

[42]        G. Naah, S. He, W. Shi, and C. Li, “Symmetrical Doherty power amplifier design via continuous harmonic-tuned Class-J mode,” AEU-International Journal of Electronics and Communications, vol. 106, pp. 96–102, 2019, doi.org/10.1016/j.aeue.2019.05.008.

[43]        G. Naah, S. He, W. Shi, C. Li, and S. Y. Nusenu, “Harmonic-tuned continuum mode active load modulation output combiner for the design of broadband asymmetric Doherty power amplifiers,” IET Microwaves, Antennas & Propagation, vol. 13, no. 8, pp. 1226–1234, 2019, doi.org/10.1049/iet-map.2018.5841.

[44]        C. Yu, Z. Su, Y. Liu, B. Tang, and S. Li, “Broadband filtering high-efficiency Doherty amplifier based on a novel post-matching network,” in 2019 European Microwave Conference in Central Europe (EuMCE), IEEE, 2019, pp. 212–215, ISBN:978-2-87487-067-5.

[45]        A. Nasri et al., “Design of a wideband Doherty power amplifier with high efficiency for 5G application,” Electronics, vol. 10, no. 8, p. 873, 2021, doi.org/10.3390/electronics10080873.

[46]        J. Kim, “Analysis and design optimisation for inverse Class-F GaN Doherty amplifier,” IET Microwaves, Antennas & Propagation, vol. 13, no. 4, pp. 448–454, 2019, doi.org/10.1049/iet-map.2018.5124.

[47]     M. Abdulhamid and J. Karugu, ‘On the design of Class-J microwave power amplifier’, International Review of Applied Sciences and Engineering, vol. 10, no. 3, pp. 225–232, 2019.