Development of GaN/Si MMIC Power Amplifiers for Millimetre-wave FMCW Radar Applications

This contribution reports the design and comparison, at simulation level, of two 4W Ka-band MMIC power amplifiers on a 100 nm GaN/Si commercial process. The amplifiers are designed targeting FMCW radar applications in the 35 GHz - 40 GHz range. The two amplifiers differ for the number of stages: one adopts only 3 stages, the minimum required to achieve the desired 20 dB small-signal gain, while the other features 4 stage to reach 20 dB also in compression. Both versions achieve in simulation an output power in excess of 36 dBm, at 5 dB gain compression, with associated power added efficiency and gain around 30% and 17 dB for the 3-stage version, and 25% and 22 dB for the 4-stage version.