A millimeter-wave field-effect transistor based on a pseudomorphic heterostructure with an additional potential barrier

We report on the results of investigations of the millimeter-wave field-effect transistors with a 0.14$\mu$m $T$-shaped gate with pseudomorphic Al$_{0.3}$Ga$_{0.7}$As-In$_{0.22}$Ga$_{0.78}$As-Al$_{0.3}$Ga$_{0.7}$As heterostructures with additional potential barriers based on a two-sided donor–acceptor channel doping. At a frequency of 40 GHz in a wide gate voltage range, the maximum stable gain of more than 15 dB has been obtained. The maximum oscillation frequency of the device is about 250 GHz, the open-channel specific current density is about 0.7 A/mm, and the gate–drain breakdown voltage is 22–31 V for different versions.