Comparison of Two Harmonic Load-Pull Systems Using Frequency-Domain and Time-Domain Measurements for Evaluating GaN Transistor Output Power and Efficiency

Authors

Keywords:

drain efficiency, GaN, harmonic load-pull, output power, power amplifier

Abstract

Two active real-time harmonic load-pull systems were developed: one operating in the time domain (TD-AHLP) and the other one in the frequency domain (FD-AHLP). The main distinction between them lies in their receivers: the first utilizes a four-channel oscilloscope, while the second uses a vector network analyzer. Measurements of output power and drain efficiency were performed using both load-pull systems on a MACOM CGH40010F GaN-HEMT transistor, biased as a Class-B power amplifier (VGS = -2.92 V, VDS = 28 V, IDS = 200 mA), at a fundamental frequency of 1 GHz. The performance of both systems was compared to evaluate the harmonic loads up to their third harmonic, output power, drain efficiency, and power gain of a Harmonic Tuned Power Amplifier (HTPA). Results demonstrate high consistency between the two systems, with mean relative deviations below 3% for both output power and drain efficiency. Both systems identify specific second-harmonic impedance regions along the periphery of the Smith chart where performance metrics remain nearly constant and largely independent of the second-harmonic reactance.

Downloads

Download data is not yet available.

Author Biographies

Edgar Hernández Limón, Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California, (CICESE)

Edgar Hernández Limón (Member, IEEE) received the B.Sc. degree in electronics sciences from the Benemérita Universidad Autónoma de Puebla, Puebla, Mexico, in 2016, and the M.Sc. degree in electronics and telecommunications from the Center for Scientific Research and Higher Education of Ensenada (CICESE), Baja California, Mexico, in 2020. He is currently pursuing the Ph.D. degree in electronics and telecommunications with a specialization in high frequencies at CICESE. His research interests include RF power amplifiers, load-pull characterization, and microwave circuits.

Daniel Alonso Tejera, Center for Scientific Research and Higher Education at Ensenada (CICESE)

Daniel Alonso-Tejera (Member, IEEE) was born in Villa Clara, Cuba. He received the B.Sc. degree in Telecommunications and Electronics Engineering from the Central University "Marta Abreu" of Las Villas in 2020. He was an Assistant Professor at the same university, where he taught antennas and radio electronics. He earned the M.Sc. degree in Electronics and Telecommunications with a focus on high frequencies from CICESE, Ensenada, Mexico, in 2024, where he is currently pursuing a Ph.D. His research interests include RF and microwave circuit design, Load-Pull techniques, waveform engineering, and power amplifiers.

J. Apolinar Reynoso Hernández, Center for Scientific Research and Higher Education at Ensenada (CICESE)

J. Apolinar Reynoso-Hernández (Member, IEEE) received the Electronics and Telecommunications Engineering degree from ESIME-IPN, Mexico, in 1984, the M.Sc. degree in Solid State Physics from CINVESTAV-IPN in 1985, and the D.E.A. and Ph.D. degrees in Electronics from LAAS-CNRS, Université Paul Sabatier, Toulouse, France, in 1987 and 1989, respectively. Since 1990, he has been a Professor at the Electronics and Telecommunications Department at CICESE, Ensenada, Mexico. His research interests include high-frequency on-wafer measurements, device modeling, and nonlinear characterization. He is main author of the book titled Principles and Applications of Vector Network Analyzer Calibration Techniques (River Publishers, 2024). He has led CICESE’s Microwave Group to receive five Best Interactive Forum Paper Awards. He has served as TPC and Workshop Organizer for ARFTG and is a regular reviewer for several IEEE journals. He is Associate Editor of IEEE transactions On Microwave Theory and Techniques.

María del Carmen Maya Sánchez, Center for Scientific Research and Higher Education at Ensenada (CICESE)

María del Carmen Maya-Sánchez (Member, IEEE) received the B.S. degree in Communications and Electronic Engineering from ESIME-IPN, Mexico City, in 1995, the M.S. degree in Electronics and Telecommunications from CICESE, Ensenada, Mexico, in 1997, and the Ph.D. degree from the Universitat Politècnica de Catalunya, Barcelona, Spain, in 2003. She was a faculty member at the Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, from 2003 to 2004. Since 2004, she has been a Researcher in the Department of Electronics and Telecommunications at CICESE, working with the High Frequency Group. Her research interests include MESFET, HEMT, and HBT device modeling, on-wafer noise measurement techniques, and the analysis, design, and characterization of microstrip and coplanar transmission lines.

José Raúl Loo Yau, Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-Guadalajara)

José Raúl Loo-Yau (Senior Member, IEEE) was born in Panamá City, Panamá. He received the degree in Electronic and Communication Engineering from the Universidad Autónoma de Guadalajara in 1998, and the M.Sc. and D.Sc. degrees in Electronics and Telecommunications with a focus on high-frequency electronics from CICESE, Ensenada, Mexico, in 2000 and 2006, respectively. Since 2007, he has been a Research Professor with the Electronic Design Group at Cinvestav-GDL. His research interests include linear and nonlinear modeling of microwave transistors, high-efficiency power amplifiers, digital predistortion, and RF active circuit design.

Manuel Alejandro Pulido Gaytan, Center for Scientific Research and Higher Education at Ensenada (CICESE)

Manuel Alejandro Pulido-Gaytan (Member, IEEE) was born in Zacatecas, México, on December 4, 1986. He received the B.S. degree in electronic engineering from the State University of Zacatecas (UAZ), Zacatecas, México, in 2010, and the M.S. and Ph.D. degrees in high-frequency electronics from the Center for Scientific Research and Higher Education at Ensenada (CICESE), Ensenada, México, in 2012 and 2016, respectively. From 2016 to 2020, he was with the Department of Applied Physics at CICESE. He is Co-author of the book titled Principles and Applications of Vector Network Analyzer Calibration Techniques (River Publishers, 2024). He is currently a Principal RF Device Modeling Engineer with Skyworks Solutions, Inc. His main research interests include the measurement, characterization, and modeling of microwave and RF devices.

Jaime Sánchez García, Center for Scientific Research and Higher Education at Ensenada (CICESE)

Jaime Sánchez-García (Member, IEEE) received the Ph.D. degree in Electrical Engineering with a specialization in communications from The George Washington University, USA, in 2001. He holds an M.Sc. in Electronics and Telecommunications from CICESE (1979), and a degree in Communications and Electronics Engineering from ESIME-IPN (1976). He is a Senior Researcher (“C” level) at the Department of Electronics and Telecommunications, CICESE, where he conducts research and teaching in wireless communications. His research interests include wireless networks, MIMO- OFDM, space-time-frequency coding, and physical-layer techniques for 4G systems. He received 1st place in the 3rd Annual Ericsson Telecommunications Award (1988) and has completed research stays at Telefónica de España, the University of Arizona, and the University of Texas at Austin.

References

F. M. Ghannouchi and M. S. Hashmi, Load-Pull Techniques with Applications to Power Amplifier Design. New York, NY, USA: Springer, 2012, doi: 10.1007/978-94-007-4461-5.

N. Khalid and A. Soury, "State-of-the-Art Load-Pull Simulation Methods for Next-Generation Power Amplifier Design," 2025 IEEE Wireless and Microwave Technology Conference (WAMICON), Cocoa Beach, FL, USA, 2025, pp. 1-4, doi: 10.1109/WAMICON64429.2025.11004099.

M. A. Pulido-Gaytán, J. A. Reynoso-Hernández, M. C. Maya-Sánchez and J. R. Loo-Yau, "The impact of knowing the impedance of the lines used in the TRL calibration on the load-pull characterization of power transistors," 2015 86th ARFTG Microwave Measurement Conference, Atlanta, GA, USA, 2015, pp. 1-5, doi: 10.1109/ARFTG.2015.7381472.

M. Marchetti, M. J. Pelk, K. Buisman, W. C. E. Neo, M. Spirito and L. C. N. de Vreede, "Active Harmonic Load–Pull With Realistic Wideband Communications Signals," IEEE Trans. Microw. Theory Techn., vol. 56, no. 12, pp. 2979-2988, Dec. 2008, doi: 10.1109/TMTT.2008.2007330.

G. Simpson, "Hybrid active tuning load pull," 77th ARFTG Microwave Measurement Conference, Baltimore, MD, USA, 2011, pp. 1-4, doi: 10.1109/ARFTG77.2011.6034576.

Y. Takayama, "A New Load-Pull Characterization Method for Microwave Power Transistors," 1976 IEEE-MTT-S International Microwave Symposium, Cherry Hill, NJ, USA, 1976, pp. 218-220, doi: 10.1109/MWSYM.1976.1123701.

G. P. Bava, U. Pisani, and V. Pozzolo, “Active load technique for load-pull characterisation at microwave frequencies,” Electron. Lett., vol. 18, no. 4, pp. 178–180, Feb. 1982, doi: 10.1049/el:19820123.

A. Ferrero and M. Pirola, "Harmonic Load-Pull Techniques: An Overview of Modern Systems," IEEE Microw. Mag., vol. 14, no. 4, pp. 116-123, June 2013, doi: 10.1109/MMM.2013.2248631.

A. Baddeley, R. Quaglia and P. J. Tasker, "Calibration Error Reduction in Millimeter-Wave Load-Pull Systems Measuring Highly Reflective Loads," IEEE Trans. Microw. Theory Techn., vol. 73, no. 6, pp. 3552-3564, June 2025, doi: 10.1109/TMTT.2024.3495544.

A. Ben Ayed and S. Boumaiza, "Millimeter-Wave Wideband Active Load-Pull System Using Vector Network Analyzer Frequency Extenders," IEEE Microw. Wireless Technol. Lett., vol. 35, no. 6, pp. 932-935, June 2025, doi: 10.1109/LMWT.2025.3564839.

M. Lindquist and P. Roblin, "Calibration of an Oscilloscope-Based NVNA for Periodic Modulated Signals," 2024 103rd ARFTG Microwave Measurement Conference (ARFTG), Washington, DC, USA, 2024, pp. 1-4, doi: 10.1109/ARFTG61196.2024.10661002.

M. Molina-Ceseña, J. A. Reynoso-Hernández, M. A. Pulido-Gaytán, J. R. Loo-Yau and M. C. Maya-Sánchez, "Experimental Investigation of Resistive–Reactive Class-J Mode Using Time-Domain Low-Frequency Active Harmonic Load–Pull Measurements," IEEE Microw. Wireless Compon. Lett., vol. 32, no. 1, pp. 96-99, Jan. 2022, doi: 10.1109/LMWC.2021.3113289.

Z. Mokhti, P. Tasker and J. Lees, "Correlation analysis between a VNA-based passive load pull system and an oscilloscope-based active load pull system: A case study," 83rd ARFTG Microwave Measurement Conference, Tampa, FL, USA, 2014, pp. 1-4, doi: 10.1109/ARFTG.2014.6899535.

C. J. Clymore et al., "First Comparison of Active and Passive Load Pull at W-Band," 2023 101st ARFTG Microwave Measurement Conference (ARFTG), San Diego, CA, USA, 2023, pp. 1-4, doi: 10.1109/ARFTG57476.2023.10279609.

I. Shilinkov, R. Maaskant and G. Lasser, "Open-Loop Active Load–Pull Setup Using the ZCU216 Radio Frequency System-on-Chip," IEEE Microw. Wireless Technol. Lett., vol. 35, no. 12, pp. 2121-2124, Dec. 2025, doi: 10.1109/LMWT.2025.3633956.

Sd J. Kim, S. K. Hong and J. Oh, "Highly Efficient Power Amplifier Based on Harmonic-Controlled Matching Network," IEEE Microw. Wireless Technol. Lett., vol. 33, no. 1, pp. 43-46, Jan. 2023, doi: 10.1109/LMWC.2022.3196669.

X. Ma, F. Liu, S. Fan, X. Liu, X. Liu, and W. Shi, “Design of High-Efficiency Concurrent Dual-Band Power Amplifier Based on Baseband and Harmonic Load Impedance Control for Wireless Communication,” Electronics, vol. 14, no. 21, Art. no. 4242, 2025, doi: 10.3390/electronics14214242.

Y. Yuan, X. Zhao, J. Fan, and Z. Yu, “Design of dual continuous-mode class-J power amplifiers with harmonic matching networks for X and Ku bands,” Micromachines, vol. 16, no. 12, Art. no. 1362, 2025, doi: 10.3390/mi16121362.

J. A. Reynoso Hernández and M. A. Pulido Gaytan, Principles and Applications of Vector Network Analyzer Calibration Techniques. River Publishers, 2024. ISBN: 978-87-7004-159-1 (print), 978-87-7004-129-4 (ebook).

J. A. Reynoso-Hernández, M. A. Pulido-Gaytán, M. C. Maya-Sánchez and J. R. Loo-Yau, "What can the ABCD parameters tell us about the TRL?," 79th ARFTG Microwave Measurement Conference, Montreal, QC, Canada, 2012, pp. 1-4, doi: 10.1109/ARFTG79.2012.6291201.

J. A. Reynoso-Hernandez et al., "Using lines of arbitrary impedance as standards on the TRL calibration technique," 81st ARFTG Microwave Measurement Conference, Seattle, WA, USA, 2013, pp. 1-4, doi: 10.1109/ARFTG.2013.6579059.

A. Ferrero and U. Pisani, "An improved calibration technique for on-wafer large-signal transistor characterization," IEEE Trans. Instrum. Meas., vol. 42, no. 2, pp. 360-364, April 1993, doi: 10.1109/19.278582.

J. Reynoso-Hernández, M. Pulido-Gaytán, T. Niubo-Aleman, and M. Molina-Ceseña, “Advances in microwave large-signal metrology: From vector-receiver load-pull to vector signal network analyzer and time-domain load-pull implementations (invited paper),” Electronics, vol. 11, no. 7, Art. no. 1114, Apr. 2022, doi: 10.3390/electronics11071114.

M. A. Chaudhary, J. Lees, J. Benedikt, and P. J. Tasker, “A sampling oscilloscope based system with active RF/IF load-pull for multi-tone non-linear device characterization,” Int. J. Microw. Opt. Technol., vol. 8, no. 3, pp. 112–119, May 2013.

N. Tuffy, L. Guan, A. Zhu and T. J. Brazil, "A Simplified Broadband Design Methodology for Linearized High-Efficiency Continuous Class-F Power Amplifiers," IEEE Trans. Microw. Theory Techn., vol. 60, no. 6, pp. 1952-1963, June 2012, doi: 10.1109/TMTT.2012.2187534.

Downloads

Published

2026-04-15

How to Cite

Hernández Limón, E., Alonso Tejera, D. ., Reynoso Hernández, J. A. ., Maya Sánchez, M. del C. ., Loo Yau, J. R. ., Pulido Gaytan, M. A., & Sánchez García, J. . (2026). Comparison of Two Harmonic Load-Pull Systems Using Frequency-Domain and Time-Domain Measurements for Evaluating GaN Transistor Output Power and Efficiency. IEEE Latin America Transactions, 24(6), 621–628. Retrieved from https://latamt.ieeer9.org/index.php/transactions/article/view/10302

Issue

Vol. 24 No. 6 (2026): Ordinary Issue

Section

Electronics