A Ku-band 100 W power amplifier under CW operation utilizing 0.15 µm GaN HEMT technology

In Japan, test satellite broadcasting of UHDTV started in August 2016 and practical broadcasting will begin in 2018. The test broadcasting is being provided in Ku-band (11.7 to 12.75 GHz) with a modulation scheme of amplitude and phase shift keying (APSK). Therefore, due to demands for non-linear characteristics in satellite transponders, we are now studying a 100-W class SSPA for a broadcasting satellite in Ku-band. In this study, we fabricated a GaN driver amplifier (DA) and a GaN high power amplifier (HPA) that both have a second harmonic reflection circuit to achieve high efficiency. They are high efficiency and high output power two-stage amplifiers using 0.15 μm GaN HEMT technology in Ku-band. Measured results showed that the DA achieved power added efficiency (PAE) of 40 % and output power exceeding 60 W under CW operation and that the HPA delivered output power of 100 W.