Impacts of continuous modes approach on the back-off efficiency of Doherty power amplifiers

ABSTRACT

This paper analyses the impacts of the harmonic-tuned hybrid continuous modes (HTHCMs) approach on the back-off efficiency of Doherty power amplifiers (DPAs). Based on the HTHCMs strategy, formulations are derived for designing the impedance inverting network (IIN) and impedance transforming network (ITN) in the DPA. Via the proposed approach, multiple impedance solutions for realizing broadband DPAs with substantial output back-off efficiency recovery is made possible. The potentiality of the design method is demonstrated by the realized prototype working from 1.4 to 2.45 GHz. Test results have shown over 50% drain efficiency at 6 dB back-off power.

KEYWORDS:

• Broadband Doherty PA
• back-off efficiency
• harmonic-tuned hybrid continuous modes
• impedance inverting network
• impedance transforming network

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Gideon Naah http://orcid.org/0000-0002-2409-1942

Additional information

Notes on contributors

Gideon Naah

Gideon Naah received the B.E. degree in computer engineering from the All Nations University College, Koforidua, Ghana in 2011, and the M.E. degree in electronics engineering from the University of Electronic Science and Technology of China, Chengdu, China in 2013. His current research interests include the design of highly efficient RF/microwave circuits and systems.

Rocco Giofrè

Dr. Rocco Giofrè was born in Vibo Valentia, Italy, in 1979. He received the M.S.Eng. degree (summa cum laude) in electronic engineering and the Ph.D. degree in space systems and technologies from the University of Roma Tor Vergata in 2004 and 2008, respectively. He is currently a Tenure Tack Assistant Professor with the Electronics Engineering Department, University of Roma Tor Vergata. He has authored or coauthored over 160 scientific papers. His research interests include RF power amplifier theory, design and test, linearization techniques, and efficiency improving techniques. He was a recipient of the 2005 Young Graduated Research Fellowship presented by the Gallium Arsenide application Symposium Association and the Best Paper Award at the 2nd EuMIC Conference in 2007.