Two-Finger InP HEMT Design for Stable Cryogenic Operation of Ultra-Low-Noise Ka- and Q-Band LNAs
Journal article, 2017

We investigate the cryogenic stability of two-finger 100-nm gate-length InP HEMTs aimed for Ka- and Q-band ultra-low noise amplifiers (LNAs). InP HEMTs with unit gate widths ranging between 30 and 50 mu m exhibit unstable cryogenic behavior with jumps in drain current and discontinuous peaks in transconductance. We also find that shorter gate length enhances the cryogenic instability. We demonstrate that the instability of two-finger transistors can be suppressed by either adding a source air bridge, connecting the back end of gates, or increasing the gate resistance. A three-stage 24-40 GHz and a four-stage 28-52-GHz monolithic microwave-integrated circuit LNA using the stabilized InP HEMTs are presented. The Ka-band amplifier achieves a minimum noise temperature of 7 K at 25.6 GHz with an average noise temperature of 10.6 K at an ambient temperature of 5.5 K. The amplifier gain is 29 dB +/- 0.6 dB. The Q-band amplifier exhibits minimum noise temperature of 6.7 K at 32.8 GHz with average noise temperature of 10 K at ambient temperature of 5.5 K. The amplifier gain is 34 dB +/- 0.8 dB. To our knowledge, the Ka- and Q-band amplifiers demonstrate the lowest noise temperature reported so far for InP cryogenic LNAs.

low-noise amplifier (LNA)

wideband

cryogenics

monolithic microwave-integrated circuit (MMIC)

InP HEMT

stability

Author

Eunjung Cha

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Giuseppe Moschetti

Niklas Wadefalk

Per-Åke Nilsson

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Stella Bevilacqua

Arsalan Pourkabirian

Piotr Starski

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Jan Grahn

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

IEEE Transactions on Microwave Theory and Techniques

0018-9480 (ISSN)

Vol. 65 12 5171-5180

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/TMTT.2017.2765318

More information

Latest update

5/8/2018 6