A Load Insensitive Doherty Power Amplifier with better than −39dBc ACLR on 2:1 VSWR Circle using a Constant 50 Ω Trained Pre-distorted Signal
Singh, G.D. (TU Delft Electronics)
Mul, D.P.N. (TU Delft Electronics)
Nemati, Hossein Mashad (Huawei Technologies)
Alavi, S.M. (TU Delft Electronics)
de Vreede, L.C.N. (TU Delft Electronics)
This paper presents a low-loss load-insensitive Doherty power amplifier (DPA) technique. The proposed DPA is insensitive to ohmic load variation by adjusting its supply voltages and input drive of the main and peaking stages in a mirrored approach. Moreover, a low-loss tunable matching network (TMN) is employed to cancel out any reactive part of the load. To validate this technique, a printed circuit board (PCB) based demonstrator consisting of the Doherty PA, a six-port reflectometer, and a tunable shunt resonator have been fabricated. When subjected to a 50 Ω load, at the 1 dB compression point, the DPA delivers an output power of 32.3 dBm with a power gain and peak drain efficiency of 14.6 dB and 61 %, respectively. When the DPA is driven with a pre-distorted 64-QAM 4 MHz signal optimized for the 50 Ω loading condition, it delivers 24.4 dBm at 41 % average drain efficiency, with EVM/ACLR −40.9 dB / −46.9 dBc. Subsequently, when subjected to a 2:1 VSWR over a 0°−360° mismatch trajectory, using the unaltered 50 Ω DPD correction, it is capable of delivering an output power of 24.4 ± 0.1 dBm with a 34–39 % drain efficiency while maintaining an EVM/ACLR better than −32.3 dB / −39.3 dBc for all load conditions.
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tunable matching networks
Proceedings of the 52nd European Microwave Conference (EuMC)
2022 52nd European Microwave Conference (EuMC), 2022-09-27 → 2022-09-29, Milan, Italy
2022 52nd European Microwave Conference, EuMC 2022
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
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© 2022 G.D. Singh, D.P.N. Mul, Hossein Mashad Nemati, S.M. Alavi, L.C.N. de Vreede