2017/09/21 by Ayushi Barthwal, Karun Rawat, Shiban K. Koul · 2 citations
Engineering · #Advanced Power Amplifier Design #Radio Frequency Integrated Circuit Design #Advanced DC-DC Converters
paper · doi:10.1109/tmtt.2017.2751044
This paper presents a design strategy to enhance the bandwidth of three-stage Doherty power amplifier (DPA) with operation upto 12-dB back-off. Based on the proposed strategy, a broadband 48-W DPA is designed and implemented using packaged CREE GaN transistors. The measured drain efficiency of 50%-61.8% at 12-dB back-off and 51.9%-66.2% at 6-dB back-off is obtained over the frequency range of 600-900 MHz. Over this 300-MHz band, the drain efficiency is between 51.1% and 78% at saturation. This corresponds to 40% fractional bandwidth. The three-stage DPA is also linearized with a three carrier 15-MHz WCDMA signal with a PAPR of 10.6 dB at various frequencies within operating band and shows the output signal qualifies spectral mask specifications.