Loss-Induced Modal Transition in a Dielectric-Coated Metal Cylindrical Waveguide for Gyro-Traveling-Wave-Tube Applications

Author

Du, Chao-Hai ; Xue, Qian-zhong ; Liu, Pu-Kun

Author_Institution

Inst. of Electron., Chinese Acad. of Sci., Beijing

Volume

29

Issue

11

fYear

2008

Firstpage

1256

Lastpage

1258

Abstract

The mode identification principles, mode structures, and propagation characteristics of electromagnetic modes in a metal cylindrical waveguide coated with an inside layer of lossy dielectric have been investigated for gyro-traveling-wave-tube applications. For the first time, the loss-induced modal transition is revealed, in which the dispersion curves of a pair of nearby modes cross each other, and their mode structures interchange. The relations among the dispersion curves, mode structures, and propagation attenuations are also presented. The distinctive discriminations of propagation properties between different modes enable us to explore many promising applications using lossy dielectric-coated waveguides.

Keywords

circular waveguides; dielectric losses; dielectric waveguides; dielectric-loaded waveguides; travelling wave tubes; waveguide transitions; dielectric-coated metal cylindrical waveguide; dispersion curves; electromagnetic modes; loss-induced modal transition; lossy dielectric; mode identification principles; mode structures; propagation attenuations; propagation characteristics; Attenuation; Dielectric devices; Dielectric losses; Dispersion; Electromagnetic propagation; Electromagnetic waveguides; Microwave devices; Microwave propagation; Propagation losses; Waveguide transitions; Dispersion relation; lossy dielectric waveguides; modal filter; modal transition;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2008.2004635

Filename

4655495