An 18–56-GHz Wideband GaN Low-Noise Amplifier With 2.2–4.4-dB Noise Figure

An 18-56-GHz gallium nitride (GaN) low-noise amplifier (LNA) monolithic microwave integrated circuit (MMIC) is presented in this letter. This LNA is fabricated with commercial 0.1-μm gate-length GaN-on-silicon (GaN/Si) process. The gain is 16-21.5 dB and the |S11| and |S22| are below -5 dB across the band. The noise figure (NF) is 2.2-4.4 dB and the output power at 1-dB compression point (P
_1
dB
) is 10-20 dBm. This LNA has four-stage-cascade and common-source structure with 4.8 × 1 mm
²
chip area. The dc power dissipation is 1.4 W. To the best of the author's knowledge, there has been no GaN LNA covering such a wide bandwidth at this frequency range. This LNA shows ultrawide bandwidth, low NF, high linearity, and high robustness. Moreover, it can be directly integrated with GaN power amplifiers (PAs) and switches to realize the monolithic RF front-ends, which can largely reduce the packaging loss and the module volume. This LNA has a great potential in wideband, high-speed, high-reliability, and high-integration applications.