Analytical Approaches to the Study of Helical Slow-Wave Structures for Broadband TWTs

Abstract

The analytical approaches developed by the authors to the problem of a helical slow-wave structure of a travelling-wave tube (TWT) are reviewed. Models developed take into account the effects of the finite thickness of the helix, the discrete dielectric support bars/rods for the helix, the proximity of a metal envelope, the finite resistivities of the metallic parts and attenuator coating on helix supports. The analysis is effective in studying the anisotropic, the inhomogeneous and the distributed-attenuator loading of the helix each of which has a relevance to broadhanding a TWT for electronic warfare applications.