A small signal theory of gyro-devices using the concept of space-charge waves

The linear theory of the interaction between a thin annular beam of gyrating electrons and a traveling electromagnetic wave is developed. This theory is very close in its methodology to the classical small signal theory of O- and M-type devices. Just this fact makes it possible to consider a number of issues in the theory of gyro-devices, namely, space-charge wave propagation in drifting electron beams, noise and parametric phenomena, effects of input signal suppression (Kompfner dip) in gyro-traveling-wave-tubes, and gyro-backward-wave-amplifiers.