Ultra-Wideband Doherty-Like Power Amplifier

Abstract

This paper presents an innovative technique, distributed efficient power amplifier (DEPA), that is suitable for wideband/multiband applications using signals with large Peak-to-Average-Power-Ratio (PAPR). DEPA replaces the auxiliary amplifier of the conventional Doherty PA (DPA) by N auxiliary sub-amplifiers distributed along an output combiner made of N-1 line sections and eliminates the load modulation associated with conventional DPA. A wideband DEPA demonstrator is designed to cover most of the wireless communications bands within two-octave bandwidth 0.65-2.6 GHz. The experimental results show that the efficiency levels are between 41-59 % and 52-66 % for output power levels at \pmb9 dB OBO and peak output power, respectively. Linearized modulated measurements using five 10 MHz LTE carriers with \pmb9 dB PAPR show an adjacent channel leakage ratio (ACLR) below \pmb-51dBc.