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 NF
_min
of ~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
$2.4\times1.3$
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.