Optimized load modulation in a Doherty amplifier using a current injection technique

T. Hone*, S. Bensmida, M. Paynter, K. Morris, M. Beach, J. McGeehan, J. Lees, J. Benedikt, P. Tasker

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)


The classical Doherty configuration suffers from a lack of accurate control of the load impedance performed by the peaking stage. The result is a reduction in the maximum obtainable efficiency and linearity performance for a given input power level. By driving the carrier and peaking power amplifiers independently, it is possible to present the optimum load to the carrier stage for either maximum efficiency, linearity or anywhere in between for any input power level. This paper proposes the injection of a controllable current into the load to create the required active load-pull. Simulations in ADS using a 10W GaN HEMT device are presented for maximum efficiency. Two different Doherty power combining networks are used and the required current for each network is explained. Measurements of a class-F amplifier in a Doherty current injection architecture are taken and drain efficiency versus output power is plotted showing a potential of 10dB dynamic range of output power with a tracked drain efficiency between 65-70%.

Original languageEnglish
Title of host publication2011 6th European Microwave Integrated Circuit Conference
Number of pages4
ISBN (Electronic)9782874870231
Publication statusPublished - 15 Dec 2011
Event6th European Microwave Integrated Circuit Conference 2011 - Manchester, United Kingdom
Duration: 10 Oct 201111 Oct 2011


Conference6th European Microwave Integrated Circuit Conference 2011
Abbreviated titleEuMIC 2011
Country/TerritoryUnited Kingdom


  • back-off high efficiency
  • Doherty amplifier
  • load modulation

ASJC Scopus subject areas

  • Hardware and Architecture
  • Electrical and Electronic Engineering


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