Improvements in dynamic and 1/f noise performances of GaAs MESFETS at cryogenic temperatures by using a monolithic process

A monolithic array of MESFETs with progressively increasing gate lengths from 1 mu m to 10 mu m and two charge preamplifiers have been designed and integrated in the same chip. Low-frequency noise and dynamic characteristics of the FETs have been measured. Measurements at 4 K and 77 K of an array of FETs with different gate-lengths have shown that D-FETs from the QED/A process by TriQuint present good noise and dynamic performances. The factor of merit H/sub f/=2.8*10/sup -26/ J obtained at 4 K is better than that of available discrete MESFETs. The preamplifier exhibits fast response and reasonable noise performance despite the use of M-FETs which do not exhibit the best noise performance of the process.<
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