Sub-THz CW clinotron oscillators with increased output power

The parameters of sub-THz CW clinotrons developed in IRE NAS of Ukraine are presented. The output power increase is achieved using optimized magnetic focusing system. Multiple-stage grating is proposed as a part of clinotron electromagnetic structure to provide the feedback by hybrid surface-volume modes that results in ohmic losses decrease in THz range. Comparison of simulation and experimental results of the interaction of the intense ribbon electron beam with hybrid surface-volume modes of sub-THz clinotron oscillator have been resented and discussed.