Simple Formulas for Stopband Attenuation Characteristics of Asymmetric Helical Slow-Wave Structures of Traveling-Wave Tubes

Author

Datta, Subrata Kumar ; Naidu, Vemula Bhanu ; Rao, P. Raja Ramana ; Kumar, Lalit ; Basu, Baidyanath

Author_Institution

Microwave Tube R&D Centre, Defence R&D Organ., Bangalore, India

Volume

57

Issue

6

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

1447

Lastpage

1454

Abstract

Simple closed-form formulas for the estimation of the π-mode stopband and the stopband attenuation in an azimuthally asymmetric helical slow-wave structure (SWS) are developed, following the coupled-mode analysis of multiple reflections. The formulas are simple and amenable to easy computation, and also allow the use of the dispersion characteristics of the structure obtainable from any standard electromagnetic modeling, thereby accruing the accuracy of 3-D electromagnetic analysis. The analysis is benchmarked against published results with close agreement. Based on the analysis, SWS configurations that would reduce the deleterious effects of asymmetry and also would improve TWT efficiency are suggested.

Keywords

slow wave structures; π-mode stopband attenuation; 3D electromagnetic analysis; TWT efficiency; azimuthally asymmetric helical slow-wave structure; electromagnetic modeling; multiple reflection coupled-mode analysis; stopband attenuation characteristics; traveling-wave tubes; Attenuation; Coupled mode analysis; Dielectrics; Electromagnetic analysis; Electromagnetic reflection; Frequency; Optical reflection; Periodic structures; Research and development; Structural rods; Angularly asymmetric helix; coupled-mode analysis; helix slow-wave structure (SWS); helix traveling-wave tube (TWT); metal segment asymmetry; periodic structures; support-rod asymmetry;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2010.2047069

Filename

5460974