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access icon free Load-modulation technique without using quarter-wavelength transmission line

© The Institution of Engineering and Technology
Received 01/11/2019, Accepted 13/05/2020, Revised 27/02/2020, Published 15/05/2020

A proposed method for achieving active load-modulation technique without using a quarter-wavelength transmission line is discussed and evaluated. The theoretical analysis shows that the active load-modulation can be achieved without using a quarter-wavelength line, where the main amplifier sees a low impedance when the input signal level is low, and this impedance increases in proportion to the amount of current contributed from the peaking amplifier. The peaking amplifier sees an impedance decreasing from infinity to the normalized impedance. To validate the method, a circuit was designed, simulated and fabricated using two symmetrical gallium nitride (GaN) transistors (6 W) to achieve a peak power of 12 W and 6 dB output back-off efficiency. The design operates with 400 MHz bandwidth at 3.6 GHz and showed an average efficiency of 50% at 6 dB back-off and an efficiency of 75% at peak power. The designed circuit was tested with CW and modulated signals, the amplifier showed an Adjacent Channel Power Ratio (ACPR) of 31–35.5 dB when tested with a wideband code division multiple access signal of 6 dB peak-average-power ratio (PAPR) at 35.5 dBm average power. Additional 20 dB of linearity improvement was achieved after adding a lineariser.

Inspec keywords: circuit simulation; gallium compounds; III-V semiconductors; MMIC power amplifiers; integrated circuit design; integrated circuit testing; modulation

Other keywords: amplifier linearity; power 6.0 W; frequency 400.0 MHz; noise figure 20.0 dB; input signal level; GaN; peaking amplifier; symmetrical gallium nitride transistors; active load-modulation technique; noise figure 6.0 dB; normalised impedance; circuit design; modulated signals; peak-average-power ratio; noise figure 31.0 dB to 35.5 dB; frequency 3.6 GHz; output back-off peak efficiency; adjacent channel power ratio; power 12.0 W

Subjects: Microwave integrated circuits; Modulation and coding methods; Analogue circuit design, modelling and testing; Amplifiers

References

    1. 1)
      • 6. Cripps, S.C.: ‘Rf power amplifiers for wireless communications’ (Artech House, USA, 2006).
    2. 2)
      • 26. Hue, X., Baroudi, F., Bollinger, L., et al: ‘12/25 w wideband ldmos power amplifier Ic (3400–3800 mhz) for 5 g base station applications’. 2017 47th European Microwave Conf. (EuMC), Nuremberg, Germany, 2017.
    3. 3)
      • 3. Ghannouchi, F.M., Hashmi, M.S.: ‘Load-pull techniques with applications to power amplifier design’ (Springer, Netherlands, 2012).
    4. 4)
      • 15. Xia, J., Yang, M., Guo, Y., et al: ‘A broadband high-efficiency Doherty power amplifier with integrated compensating reactance’, IEEE Trans. Microw. Theory Tech., 2016, 64, (7), pp. 2014–2024.
    5. 5)
      • 13. Watanabe, S., Takayama, Y., Ishikawa, R., et al: ‘A broadband Doherty power amplifier without a quarter-wave impedance inverting network’. 2012 Asia Pacific Microwave Conf. Proc., Kaohsiung, Taiwan, 2012.
    6. 6)
      • 27. Maroldt, S., Ercoli, M.: ‘3.5-Ghz ultra-compact gan class-E integrated Doherty mmic Pa for 5 g massive-mimo base station applications’. 2017 12th European Microwave Integrated Circuits Conf. (EuMIC), Nuremberg, Germany, 2017.
    7. 7)
      • 29. Zhou, J., Chen, W., Chen, L., et al: ‘3.5-0 Hz high-efficiency broadband asymmetric Doherty power amplifier for 5 g applications’. 2018 Int. Conf. on Microwave and Millimeter Wave Technology (ICMMT), Chengdu, China, 2018.
    8. 8)
      • 18. Qureshi, J.H., Nan, L., Neo, E., et al: ‘A wide-band 20w ldmos Doherty power amplifier’. 2010 IEEE MTT-S Int. Microwave Symp., Anaheim, CA, USA, 2010.
    9. 9)
      • 14. Zhou, X.Y., Chan, W.S., Zheng, S.Y., et al: ‘A mixed topology for broadband high-efficiency Doherty power amplifier’, IEEE Trans. Microw. Theory Tech., 2019, 67, (3), pp. 1050–1064.
    10. 10)
      • 11. Özen, M., Andersson, K., Fager, C.: ‘Symmetrical Doherty power amplifier with extended efficiency range’, IEEE Trans. Microw. Theory Tech., 2016, 64, (4), pp. 1273–1284.
    11. 11)
      • 10. Sajedin, M., Elfergani, I.T.E., Rodriguez, J., et al: ‘A survey on Rf and microwave Doherty power amplifier for Mobile handset applications’, Electronics (Basel), 2019, 8, (6), p. 717.
    12. 12)
      • 5. Doherty, W.H.: ‘A new high-efficiency power amplifier for modulated waves’, Bell Syst. Tech. J., 1936, 15, (3), pp. 469–475.
    13. 13)
      • 4. Kim, B.: ‘Doherty power amplifiers: from fundamentals to advanced design methods’ (Elsevier Science, UK, 2018).
    14. 14)
      • 24. Pang, J., He, S., Dai, Z., et al: ‘Novel design of highly-efficient concurrent dual-band gan Doherty power amplifier using direct-matching impedance transformers’. 2016 IEEE MTT-S Int. Microwave Symp. (IMS), San Francisco, CA, USA, 2016.
    15. 15)
      • 17. Bathich, K., Markos, A.Z., Boeck, G.: ‘Frequency response analysis and bandwidth extension of the doherty amplifier’, IEEE Trans. Microw. Theory Tech., 2011, 59, (4), pp. 934–944.
    16. 16)
      • 23. Nikandish, G., Staszewski, R.B., Zhu, A.: ‘Bandwidth enhancement of gan mmic Doherty power amplifiers using broadband transformer-based load modulation network’, IEEE Access, 2019, 7, pp. 119844–119855.
    17. 17)
      • 12. Rawat, K., Ghannouchi, F.: ‘Load-pull assisted cad design of inverted Doherty amplifier without quarter-wave transformer’. 2012 25th IEEE Canadian Conf. on Electrical and Computer Engineering (CCECE), Montreal, Canada, 2012.
    18. 18)
      • 20. Kang, H., Lee, H., Lee, W., et al: ‘Octave bandwidth Doherty power amplifier using multiple resonance circuit for the peaking amplifier’, IEEE Trans. Circuits Syst. I, Regul.Pap., 2019, 66, (2), pp. 583–593.
    19. 19)
      • 9. Abdulkhaleq, A.M., Yahya, M.A., McEwan, N., et al: ‘Recent developments of dual-band Doherty power amplifiers for upcoming Mobile communications systems’, Electronics. (Basel), 2019, 8, (6), p. 638.
    20. 20)
      • 8. Ren, H., Shao, J., Arigong, B., et al: ‘Simplified Doherty power amplifier structures’. 2015 Texas Symp. on Wireless and Microwave Circuits and Systems (WMCS), Waco, TX, USA, 2015.
    21. 21)
      • 28. Huang, C., He, S., Dai, Z., et al: ‘A 80 w high gain and broadband Doherty power amplifier for 4/5 g wireless communication systems’. 2016 IEEE MTT-S Int. Microwave Symp. (IMS), San Francisco, CA, USA, 2016.
    22. 22)
      • 16. Yang, Z., Yao, Y., Li, M., et al: ‘Bandwidth extension of Doherty power amplifier using Complex combining load with noninfinity peaking impedance’, IEEE Trans. Microw. Theory Tech., 2019, 67, (2), pp. 765–777.
    23. 23)
      • 30. Abdulkhaleq, A.M., Yahya, M.A., Al-Yasir, Y.I.A., et al: ‘Doherty power amplifier for LTE-advanced systems’, Technologies, 2019, 7, (3), p. 60.
    24. 24)
      • 2. Wang, Z.: ‘High-efficiency load modulation power amplifiers for wireless communications’ (Artech House Publishers, UK, 2017).
    25. 25)
      • 25. Pang, J., He, S., Huang, C., et al: ‘A post-matching Doherty power amplifier employing low-order impedance inverters for broadband applications’, IEEE Trans. Microw. Theory Tech., 2015, 63, (12), pp. 4061–4071.
    26. 26)
      • 22. Abadi, M.N.A., Golestaneh, H., Sarbishaei, H., et al: ‘An extended bandwidth Doherty power amplifier using a novel output combiner’. 2014 IEEE MTT-S Int. Microwave Symp. (IMS2014), Tampa, FL, USA, 2014.
    27. 27)
      • 21. Barthwal, A., Rawat, K., Koul, S.K.: ‘A design strategy for bandwidth enhancement in three-stage Doherty power amplifier with extended dynamic range’, IEEE Trans. Microw. Theory Tech., 2018, 66, (2), pp. 1024–1033.
    28. 28)
      • 19. Giovannelli, N., Cidronali, A., Singerl, P., et al: ‘A 250 w ldmos doherty Pa with 31% of fractional bandwidth for dvb-T applications’. 2014 IEEE MTT-S Int. Microwave Symp. (IMS2014), Tampa, FL, USA, 2014.
    29. 29)
      • 7. Camarchia, V., Pirola, M., Quaglia, R., et al: ‘The Doherty power amplifier: review of recent solutions and trends’, IEEE Trans. Microw. Theory Tech., 2015, 63, (2), pp. 559–571.
    30. 30)
      • 1. Colantonio, P., Giannini, F., Limiti, E.: ‘High efficiency Rf and microwave solid state power amplifiers’ (John Wiley & Sons, UK, 2009).
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