This work provides comparative studies of a double -doped Al0.3Ga0.7As/InxGa1−xAs/GaAs symmetrically graded x = 0.15 → 0.2 → 0.15 doped-channel field-effect transistor DD-DCFET with respect to a conventional double -doped pseudomorphic high electron mobility transistor pHEMT and a conventional DCFET structure. All threes samples, grown by the low-pressure metallorganic chemical vapor deposition...