Design of a Class-F Power Amplifier with GaN Device Model and Reflection Data

Abstract

A Class F power amplifier (PA) operating in the 2.5–2.7 GHz frequency band has been designed, fabricated, and tested using a gallium nitride high electron mobility transistor (GaN HEMT). The amplifier has a peak power-added efficiency (PAE) of 76.4% and output power of 8.5W with a 12.3 dB gain. This combination of high gain and high-efficiency operation across a wide frequency range creates opportunity for the design’s use in various commercial and defense applications where power consumption is a major design factor. Advanced design system (ADS) from Keysight is used for the design and simulation process. The input matching network and harmonic termination circuits are designed using the reflection data of the transistor which is extracted using non-linear model over harmonic balance analysis. The output matching circuit is designed using the obtained load pull data after the harmonic termination network design is completed. The design procedure is presented in detail, the input and output matching circuits are made according to a specific method and order. The design based on the usage of reflection data is obtained under large signal conditions. These data are then defined and evaluated as a network termination in the ADS tool. This termination hence enabled us to design harmonic suppression and output matching networks regarding the output impedance of the transistor. While design and optimization is not an easy task for non-linear analysis, it is observed that the followed and proposed procedure makes such designs easier and practical with successful results.

KEYWORDS:

• Class-F
• Efficiency
• GaN HEMT
• Harmonic termination circuit
• Input matching circuit
• Power amplifier

Additional information

Notes on contributors

Merve Alemdag

Merve Alemdag received her BSc and MSc degrees from Istanbul University in electrical and electronics engineering 2015 and 2018, respectively. She is currently studying towards her PhD degree in Istanbul University – Cerrahpasa. She is currently a senior hardware design engineer with the Research and Development Department in NETAS Telecommunication. Her research interests are RF power amplifiers, high technology analog, and digital circuits design.

Firat Kacar

Firat Kacar received his BSc, MSc and PhD degrees from Istanbul University in electrical and electronics engineering 1998, 2001, and 2005, respectively. He is currently professor at the Electrical and Electronics Engineering Department of Istanbul University – Cerrahpasa. His current research interests include analog circuits, active synthetic inductors, CMOS-based circuits and electronic device modeling. He is the author or co-author of about 100 papers. Email: [email protected]

Sedat Kilinc

Sedat Kilinc received his BSc and MSc degrees in electronics and communications engineering from Yildiz Technical University and Technical University of İstanbul in 2012 and 2015. He is currently studying towards his PhD degree in Technical University of Istanbul. He has been a research assistant in Istanbul University – Cerrahpasa since 2012. His research interests are microwave and RF circuits, microwave power amplifier design, semi-analytical techniques for wideband microwave power transfer network design and synthesis with lumped and distributed elements. Email: [email protected]