Ultra-Wideband Doherty-Like Power Amplifier

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 9 dB OBO and peak output power, respectively. Linearized modulated measurements using five 10MHz LTE carriers with 9 dB PAPR show an adjacent channel leakage ratio (ACLR) below -51 dBc.