Slow-wave structure “longitudinally-connected rings” with small periodisity

A novel slow-wave structure (SWS) formed by longitudinally connected rings is offered and investigated in this paper. It is shown that provided by the offered structure slowing down (deceleration) does not depend significantly on the period and is much less than in the case of the helix with the same radius and period. In the same time, the dispersion property of the offered structure insufficiently differs from that of the helix. The deceleration dependence on frequency is relatively flat and such SWS can be used in the wideband TWTs instead of the helix. Due to a relatively small deceleration, the operating voltage of TWTs can be significantly increased without the backward wave oscillation at minus first spatial harmonic. This leads in turn to the significant increase in the operating current and the output power, as well as in possibility to increase the operating frequency.