Packaged 7 GHz GaN MMIC Doherty Power Amplifier

This paper reports on a packaged GaN MMIC Doherty Power Amplifier operating in the 7 GHz band. The power amplifier exhibits a small-signal gain of 18 dB from 7.0 GHz to 8.0 GHz and the saturated output power is more than 42 dBm across the same frequency band. Measured power added efficiency is better than 24% in 10 dB back-off from saturation. The linearity of the amplifier is excellent achieving a NMSE of -38 dB without DPD and -52 dB with DPD. The power amplifier was implemented in a 0.25 um gate-length GaN-HEMT technology and packaged in a QFN 6 mm x 6 mm package using plastic overmold. The dimensions of the MMIC were 4.38 mm x 4.38 mm. These results represent current state-of-the-art in high efficiency power amplifiers for wireless backhaul applications.