Abstract:

Coaxial slow wave structure with two sectional inner corrugated conductors is applied in relativistic backward wave oscillator to explore dual-frequency high pow er microwave output.The dispersion equation of the coaxial SWS is derived.The dispersion properties of the structure are numerically investigated.Preliminary study has been also made on the mechanism of the X-band dual-requency HPM output from the RBWO.In the analysis，two different conditions of dual-frequency points have been considered：working efficiency of the beam is invariable or a little drop when interacting in the second part of SWS.Through the simulation calculation of 2.5-dimensional fully electromagnetic particle-in-cell simulation code，the reliability of dual-frequency microwave signals is validated.

Key words: HPM, X-band, dual-frequency, RBWO