Generation of Dissipative Soliton Combs Based on Electron-wave Interaction

We study the possibility of developing high-power pulse-periodic microwave radiation sources based on an analogy with the formation of soliton frequency combs in optical systems, namely, in lasers with passive mode-locking and in non-linear microresonators pumped by laser radiation. In both cases, the generated pulses can be interpreted as dissipative solitons. Passive mode-locking is implemented in two-section generators comprising a coupled electron amplifier and a saturable absorber. Absorbers, applicable to the microwave frequency range and suitable for operation at high power levels, can be implemented based on interaction with an electron beam as a result of the cyclotron resonant absorption or in the Kompfner dip regime. An analogue of microcavity frequency combs can be realized in the case of instability of a monochromatic wave in a high-Q resonator due to interaction with an electron beam, under conditions where electron susceptibility is a practically real value. The paper includes both a theoretical analysis of the indicated mechanisms in microwave electronics, and the results of experiments on the implementation of a Ka-band electron generator with passive mode locking.