A new two-mode channel FET (TMT) for super-low-noise and high-power applications

A super-low-noise two-mode channel FET (TMT) with high- and plateau-shaped transconductance (g/sub m/) characteristics has been developed. It has two electron transport modes against the applied gate voltage (V/sub gs/). That is, the electrons mainly drift in a highly doped channel region at a shallow V/sub gs/. A plateau g/sub m/ region and the maximum g/sub m/ were achieved at a V/sub gs/ range of -0.25 approximately +0.5 V and 535 mS/mm, respectively. The minimum noise figure and associated gain for the TMT were superior in the low-drain-current (I/sub ds/) region and nearly equal in the middle and high I/sub ds/ region to those of an AlGaAs/InGaAs pseudomorphic HEMT fabricated using the same wafer process and device geometry.<
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