A theory of the attenuator-coated helical slow-wave structure of a traveling-wave tube

Author

Jain, P.K. ; Basu, B.N.

Author_Institution

Dept. of Electron Eng., Banaras Hindu Univ., Varanasi, India

Volume

35

Issue

10

fYear

1988

fDate

10/1/1988 12:00:00 AM

Firstpage

1750

Lastpage

1757

Abstract

A theory of the attenuator-coated helical slow-wave structure of a traveling-wave tube has been developed by considering the helix turns to be effectively shorted by a resistive coating. Power propagating down the structure is interpreted for the interaction impedance in the presence of the attenuator-coating losses. The dependence of the attenuation and phase propagation constants as well as the interaction impedance on the surface resistivity of the coating, the operating frequency, the thickness/proximity of the envelope, the permittivity of the dielectric, and the pitch of the helix have been studied for two situations in which the attenuator coating is applied: (1) inside a dielectric tube that the helix fits into, the whole enclosed in a metal envelope: and (2) over a dielectric tube enclosure for the helix

Keywords

losses; travelling-wave-tubes; TWT; attenuator-coated helical slow-wave structure; attenuator-coating losses; dielectric tube enclosure; envelope thickness; helix pitch; interaction impedance; metal envelope; microwave tube; operating frequency; permittivity; phase propagation constants; resistive coating; shorted helix turns; surface resistivity; traveling-wave tube; Attenuation; Attenuators; Coatings; Conductivity; Dielectrics; Frequency; Permittivity; Propagation constant; Propagation losses; Surface impedance;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.7381

Filename

7381