Single-Ended Branch PA Characterisation for Outphasing Amplifiers

Paolo Enrico de Falco, Konstantinos Mimis, Souheil Ben-Smida, Kevin Morris, Gavin Watkins, Atsushi Yamaoka, Keiichi Yamaguchi

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

3 Citations (Scopus)


Back-off efficiency is a key requirement for load modulated power amplifier (PA) architectures such as Chireix outphasing. This paper studies the impact of second and third harmonic impedance tuning (Z 2fo ,Z 3fo ) on the performance of a 10 Watt GaN HEMT branch PA subject to outphasing-like load modulation, operating at 900 MHz. Performance variation of up to 3 dB output power (POUT) and 50% points drain efficiency (DE) with phase manipulation alone of Z 2fo is recorded. Optimal Z 2fo is revealed to vary - throughout a fixed and for different - outphasing trajectories. A simple technique is presented, using continuous class F -1 closed form equations, which predicts the intrinsic optimal Z 2fo for multiple points from five outphasing load trajectories, de-embedded to the current generator (CG) plane of the device.

Original languageEnglish
Title of host publication2018 13th European Microwave Integrated Circuits Conference (EuMIC)
Number of pages4
ISBN (Electronic)9782874870521
Publication statusPublished - 19 Nov 2018
Event13th European Microwave Integrated Circuits Conference 2018 - Madrid, Spain
Duration: 24 Sept 201825 Sept 2018


Conference13th European Microwave Integrated Circuits Conference 2018
Abbreviated titleEuMIC 2018


  • harmonically tuned
  • outphasing
  • PA

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Instrumentation


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