A Broadband 70-110-GHz E-/W-Band LNA Using a 90-nm T-Gate GaN HEMT Technology

This letter describes the design and measured performance of an E-/W-band GaN MMIC low-noise amplifier based on a 90-nm T-gate GaN technology. The GaN technology is characterized by a peak fT of 145 GHz and an NFmin of similar to 1.2 dB at 50 GHz. The LNA is comprised of a four-stage common-source amplifier designed to operate over a 70-110-GHz frequency band. From 70 to 89 GHz, the amplifier achieves 15-17.9 dB of gain and an NF of 3.5-4.2 dB over a 75-83 GHz measured subband. From 90 to 110 GHz, the amplifier achieves a gain from 15.8 to 19.2 dB and an NF of 3.3-3.8 dB over a 91-96-GHz measured subband. These are believed to be the lowest NFs achieved from a single GaN amplifier covering both E- and W-frequency bands. The MMIC is 2.4 x 1.3 mm(2) in size and consumes 200 mW of dc power from a 5-V supply. The GaN LNA can be integrated with a PA and RF switch to form a compact GaN TR MMIC solution.