On the TWT based on a helix slow-wave structure sustained by rectangular dielectric rods

Inhomogeneous dielectric loading is a necessary approach to obtain an accur ate simulation of a helix slow-wave structure in traveling-wave tubes. In t his paper a new expression for the effective dielectric constant to charact erize each dielectric coaxial tube in which the region between the helix an d the envelope is divided for the ease of a rectangular rod is proposed. Th e use of this expression in a rigorous analysis method results in a more ac curate simulation of the helix slow-wave structure. (C) 1999 John Wiley & S ons, Inc.