Two-stage dielectric-loading for broadbanding a gyro-TWT

A scheme of dielectric-loading for a gyro-traveling wave tube (gyro-TWT) is proposed for a wider bandwidth at a higher gain. The method uses two-section dielectric-loaded cylindrical waveguide as the interaction structure, with the first section overloaded to exhibit a valley between the two peaks in the gain-frequency response, while the other suitably loaded to exhibit a single peak centered at the valley so as to yield an overall wideband response. A bandwidth ~8.8% at a relatively high small-signal gain ~30 dB is predicted