Digital Microwave Power Amplifier with Energy Recovery
IEEE MTT-S Int. Microw. Symp. Dig., San Francisco, USA, May 22-27, THIF2-1 (2016).
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The paper presents a digital microwave power amplifier (DPA) for the 900 MHz band which utilizes two GaN DPA MMICs, a wideband 180° hybrid coupler and a chargepump voltage-doubler rectifier to improve efficiency at power back-off (PBO). Output power peaks at 7.5 W with a maximum overall PAE of 42%. The energy to be recovered is collected at the isolated port of the coupler. It is converted to DC and can assist in supplying the PA. By using the energy recovery the overall PAE of the PA in digital Doherty operation is improved and final-stage drain efficiencies of 74% and 52% at 6 dB and 10 dB PBO are achieved, respectively.
Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
Power amplifiers (PAs), digital, energy recovery, charge-pump, 180° hybrid coupler.