Frequency Selective Degeneration for 6–18 GHz GaAs pHEMT Broadband Power Amplifier Integrated Circuit
, Eunjoo Yoo †, Hansik Oh, Hyungmo Koo, Jaekyung Shin, Keum Cheol Hwang, Kang-Yoon Lee and Youngoo Yang *Round 1
Reviewer 1 Report
This manuscript is well-organized and well-written. This work includes the simulation and experimental studies on optimizing the capacitor and resistor values to improve the degeneration and frequency range of pHEMT broadband PAIC. The specifications of resulting PAIC chip are outstanding compared to previous works in terms of chip size, gain, gain flatness, input/output reflection characteristics.
This manuscript could be accepted for publication. Comments about the writing: (1) please include what PAE and “pHEMT” stand for; (2) please include the mathematic definition/description of gain flatness, Pout flatness and PAE; (3) please introduce “Win Semiconductors GaAs pHEMT process” in the text; and (4) please briefly introduce what are the advantage and disadvantages of using GaAs for PAIC chip compared to GaN, SiGe and other materials.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper deals on the design of a broadband power amplfier. It is very interesting and perfomance are good.
The work is well organized and both simulations and measurements are reported and there is a good agreement on S paramenters.
Just some considerations:
Please specify the simulation software and if the simualted results here proposed have been obtained with electrical or EM simulations.
References are quite old.
Please include and comment some more recent works relative to broadband power amplifiers, as for instance:
- C. Huang, S. He, W. Shi and B. Song, "Design of Broadband High-Efficiency Power Amplifiers Based on the Hybrid Continuous Modes With Phase Shift Parameter," in IEEE Microwave and Wireless Components Letters, vol. 28, no. 2, pp. 159-161, Feb. 2018, doi: 10.1109/LMWC.2017.2787061.
- R. Amirpour, R. Darraji, F. Ghannouchi and R. Quay, "Enhancement of the Broadband Efficiency of a Class-J Power Amplifier With Varactor-based Dynamic Load Modulation," in IEEE Microwave and Wireless Components Letters, vol. 27, no. 2, pp. 180-182, Feb. 2017, doi: 10.1109/LMWC.2016.2646905.
- P. Saad, R. Hou, R. Hellberg and B. Berglund, "A 1.8–3.8-GHz Power Amplifier With 40% Efficiency at 8-dB Power Back-Off," in IEEE Transactions on Microwave Theory and Techniques, vol. 66, no. 11, pp. 4870-4882, Nov. 2018, doi: 10.1109/TMTT.2018.2867426.
- B. Liu, M. Mao, D. Khanna, C. Boon, P. Choi and E. A. Fitzgerald, "A Novel 2.6–6.4 GHz Highly Integrated Broadband GaN Power Amplifier," in IEEE Microwave and Wireless Components Letters, vol. 28, no. 1, pp. 37-39, Jan. 2018, doi: 10.1109/LMWC.2017.2772806.
Stability is an important point relative to power ampliers. In your work this aspect has not been addressed at all. Please discuss this point and consider the following papers relative to the effect of feedack networks in the stabiliy of multi-transistor PAs.
- L. Pantoli, G. Leuzzi, A. Santarelli, F. Filicori and R. Giofrè, "Stabilisation approach for multi-device parallel power amplifiers under large-signal regime," 2011 6th European Microwave Integrated Circuit Conference, Manchester, 2011, pp. 144-147.- refs
Author Response
Please see the attachment
Author Response File: Author Response.pdf
