J. Phys. IV France
Volume 12, Number 3, May 2002
Page(s) 121 - 124

J. Phys. IV France
12 (2002) Pr3-121
DOI: 10.1051/jp420020049

Investigations on the low-power and low-frequency noise performance of pHEMT at 4.2 K

T. Lucas and Y. Jin

LPN, CNRS, route de Nozay, 91460 Marcoussis, France

Pseudomorphic GaAs HEMTs with a gate length of 1 $\mu$m have been realized and characterized at 4.2K. For the device with a gate width of 4mm, a gate leakage current less than 1pA and a total input capacitance lower than 10pF have been obtained for any practical bias conditions. The channel resistance can be modified more than 10 9 times with a gate bias variation less than a half volt. An intrinsic voltage gain higher than 10 can be reached with a power dissipation equal to or less than 0.15mW. Under this power supply condition, equivalent input noise voltages of 8.4, 3.2 and down to 1.3nV/vHz can be obtained at frequencies of 1, 10 and 100kHz respectively. This noise voltage has been studied as a function of the drain current. Finally, the experimental results of this work have shown that the device's noise voltage can be linked to its DC parameters.

© EDP Sciences 2002