A Q-band power amplifier MMIC using 100 nm AlGaN/GaN HEMT

The next generation of satellite communication systems at Q/V-band increases the need for highly performing MMIC technology. Gallium nitride high electron mobility transistors (GaN HEMTs) can provide high power density even at millimeter wave frequencies. Targeting a band of 35-40 GHz, a power amplifier MMIC using second-harmonic input and output matching is designed, manufactured, and measured. The presented single-transistor MMIC exhibits a small-signal gain of more than 9 dB at 38 GHz and delivers 269 mW (24.3 dBm) of output power at 38 GHz, which results in a power density of over 1.2 W/mm. The amplifier shows a drain efficiency of up to 33 % and a power-added efficiency (PAE) of up to 22 %.