Power Amplifiers Load Modulation Techniques for 5G in GaN-on-Si Techonology

A Doherty power amplifier (DPA) and a Chireix power amplifier for 5th Generation (5G) wireless applications are presented in this paper. The power amplifiers are integrated in OMMIC 100 nm GaN-on-Si process. In both amplifiers, the λ/4 T-Line are replaced with lumped-elements to reduce its area. The DPA presents a P_sat of 34 dBm (>2.5 W), a peak PAE of 41 % and a 9.4 dB gain at 3.6 GHz. At 7 dB output back-off (OBO) it exhibits a 34.2 % PAE. On the other hand, the Chireix outphasing PA provides a P_sat of 32 dBm (>1.5 W), a peak PAE of 54.9%, a gain of 10.4 dB and a 25 % PAE at 7 dB OBO. The occupied area of the DPA and Chireix amplifiers are 3.26 mm²and 3.2 mm², respectively, including pads.