Small-signal field analysis of gyro-TWT amplifier

Abstract

The corrected dispersion relation governing the linear interaction of a TE mode in a circular cylindrical wave guide with an annular beam of gyrating electrons in a gyro-TWT configuration is derived. When the cyclotron resonance condition is satisfied by the TE mode for a positive s-number, the small-signal theory is shown to give rise to an initial exponential growth of the mode with axial distance over a small but finite band of frequencies around the design frequency.