A 3.5G 500W Asymmetric Doherty Amplifier Employing Subharmonic Oscillation Suppression

This paper presents a novel Asymmetric Doherty Amplifier in 3way (ADPA-3way) for 5G macro station application at the pioneer band (3.4∼3.8 GHz). This ADPA-3way contains a main path and a two-paths peak that combines two auxiliary Gallium Nitride (GaN) high electron mobility transistors (HEMT) as a single-end high power path. An oscillation suppression network is designed at the input circuit of the two-paths peak, to mitigate the subharmonic oscillation. This ADPA-3way demonstrates over 500 watts peak power capability over the pioneer band, of linear gain 12 dB. Drain efficiency at average output power of 76 watts achieves 47.5 %, Adjacent Channel Power Ratio (ACPR) of −55 dBc with 2 adjacent Long-Term-Evolution (LTE) signals after Digital Pre-Distortion (DPD) correction.