Gallium nitride MMICs for mm-wave power operation

In this paper a Gallium Nitride MMIC technology for high-power amplifiers between 27 GHz and 101 GHz based on 150 nm- and 100 nm-gate technologies is presented. The GaN HEMT MMICs are designed using coplanar waveguide transmission-line-technology on 3-inch semi-insulating SiC substrates. The measured output power of several dual-stage GaN HPA MMICs amounts to 33-34 dBm at 27-28 GHz with a reproducible measured small-signal gain of 10 dB. Optimized GaN test structures matched to 27 GHz provide a maximum PAE of 28 % with an associate output power of 2 W/mm at 27 GHz in cw-operation. In pulsed operation with 10 % duty-cycle, a PAE level of >35% is achieved with a power density of 4.5 W/mm, again at 27 GHz. GaN HEMT MMICs at 60 GHz provide gain levels of >6 dB per amplifier stage, while a MIMIC at 101 GHz reaches 3.2 dB of gain.