InAs/AlSb HEMTs for cryogenic LNAs at ultra-low power dissipation
Journal article, 2011
Properties of the InAs/AlSb high electron mobility transistor, essential for the design of a cryogenic low-noise amplifier (LNA) operating at low power dissipation, have been studied. Upon cooling from 300 K to 77 K. the dc transconductance g(m) was enhanced by 30% at a drain-source voltage V(DS) of 0.1 V. The gate current leakage showed a strong reduction of the Schottky current component at 77 K. Compared to 300 K, the cut-off frequency f(T) and maximum oscillation frequency f(max) showed a significant improvement at 77 K with a peak f(T) (f(max)) of 167 (142) GHz at V(DS) = 0.2 V. The suitability of the Sb HEMT for a cryogenic LNA design up to 50 GHz, operating at low dc power dissipation, was investigated through the extraction of the NF(tot,min) figure of merit. It was found that the best device performance in terms of noise and gain is achieved at a low V(DS) of 0.16 v resulting in a minimum NF(tot,min) of 0.6 dB for a frequency of 10 GHz when operating at 77 K. A benchmarking between the Sb HEMT and an InP HEMT has been conducted highlighting the device improvement in noise and gain required to reach today's state-of-the-art cryogenic LNAs.
Low noise amplifier