“…Here we expect an increase in the amplitude of the microwave signal, all other factors being equal. As is well known [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47], the negative dynamic resistance (NDR) effects may be enhanced in transit-time devices if the phase lag of the modulation component of the current, which is in anti-phase with the local electric field, is increased. For this reason, the use of SiC is promising also owing to the fact that the charge mobility in the SiC polytypes is rather small, which should lead to an increase in the phase delay between the current and the alternating electric field in the microwave range and, hence, to an increase in the absolute magnitude of NDR and available microwave power (see, for example, figure 11 [36,37]).…”