Watt-Level 21–25-GHz Integrated Doherty Power Amplifier in GaAs Technology

This letter presents the design and characterization of a Doherty power amplifier for K-band applications based on the GaAs 150-nm pseudomorphic HEMT (pHEMT) technology of Qorvo. For the output power combiner, a wideband design approach, based on embedding the output capacitance of the active devices in the combiner, is applied. A state-of-the-art bandwidth of 4 GHz is achieved: in the 21-25-GHz range, the output power is above 29.5 dBm, with an associated power added efficiency (PAE) higher than 30%. At 6-dB output back-off, the PAE is above 19% while the corresponding gain is higher than 10 dB.