A > 120-GHz Bandwidth, >20-dBm Pout, <6-dB Noise-Figure Distributed Amplifier MMIC in a GaN-on-SiC HEMT Technology

This article demonstrates a distributed amplifier (DA) monolithic microwave integrated circuit (MMIC) with a 3-dB S21 bandwidth (BW) of 2–129GHz fabricated in a gallium nitride (GaN) HEMT technology. Furthermore, the article investigates the prediction of the third-order intermodulation point (IP3) on device and DA level based on dc I–V measurements and compares two analytical approaches. The equations can be used as well as a design tool before the actual circuit design. The DA consists of eight cells based on common-source transistors with an average S21 of 6.7 dB. Within a frequency range from 2 to 110 GHz, the measured output-referred 1-dB compression point and saturated output power are between 17.9–20.2dBm and 20.6–22 dBm, respectively. This is the first demonstration of an amplifier MMIC with an output power of more than 20dBm over a 100-GHz BW. Up to 70 GHz, the measured output-referred IP3 is between 26.8 and 29.8 dBm. In addition to state-of-the-art large-signal performance, the DA exhibits also an excellent noise figure (NF) with values between 3.1 and 5.7 dB (2–110 GHz).