A 70-W Asymmetrical Doherty Power Amplifier for 5G Base Stations

Much attention has been paid to making 5G developments more energy efficient, especially in view of the need for using high data rates with more complex modulation schemes within a limited bandwidth. The concept of the Doherty power amplifier for improving amplifier efficiency is explained in addition to a case study of a 70 W asymmetrical Doherty power Amplifier using two GaN HEMTs transistors with peak power ratings of 45 W and 25 W. The rationale for this choice of power ratio is discussed. The designed circuit works in the 3.4 GHz frequency band with 200 MHz bandwidth. Rogers RO4350B substrate with dielectric constant er = 4.66 and thickness 0.035 mm is used. The performance analysis of the Doherty power amplifier is simulated using AWR MWO software. The simulated results showed that 54–64% drain efficiency has been achieved at 8 dB back-off within the specified bandwidth with an average gain of 10.7 dB.

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