Doherty Load Modulation Based on Non-Reciprocity

Paper in proceeding, 2021

This paper presents a new type of Doherty power amplifiers (DPA) based on non-reciprocal power combiners. We replace the conventional quarter-wave (λ/4) impedance inverter in a DPA by a non-reciprocal gyrator. As proof of concept, a DPA using a commercial circulator has been implemented. The
prototype PA exhibits a peak output power of 49.1 ± 0.1dBm and efficiency between 57-68% at 6 dB output back-off (OBO) across 2.08 -2.14 GHz. Linearized modulated measurements, using 10MHz LTE signal with 7.8 dB PAPR, show an average output power of 13 W, an average drain efficiency of 54 %, and an adjacent channel leakage ratio (ACLR) lower than -55 dBc.