Designing a 3.5 GHz Doherty Power Amplifier Using GaAs HBT for 5G NR Communications

Abstract

This paper discusses the design of a 3.5-GHz band Doherty power amplifier using a 0.5-μm GaAs process. The design was optimized through load-pull simulations, employing the second harmonic trap filter at the output of the peaking amplifier to maintain high linearity. Measurement results of the fabricated power amplifier showed a maximum saturated power of 27.8 dBm and power-added afficiency (PAE) of 34.3 % in the 3.5 GHz band. Additionally, with a 5G NR 64-QAM 100-MHz modulated signal, it achieved a linear output power of 22 dBm with an EVM of 5.6 % and a linear output power added efficiency of 19.8 %.