Impact of Random Fabrication Errors on Fundamental Forward-Wave Small-Signal Gain and Bandwidth in Traveling-Wave Tubes With Finite-Space-Charge Electron Beams

Author

Sengele, Sean ; Barsanti, Marc L. ; Hargreaves, Thomas A. ; Armstrong, Carter M. ; Booske, John H. ; Lau, Y.Y.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Wisconsin-Madison, Madison, WI, USA

Volume

60

Issue

3

fYear

2013

fDate

Mar-13

Firstpage

1221

Lastpage

1227

Abstract

The 1-D small-signal theory for the fundamental spatial harmonic mode developed by Pengvanich et al. is adapted to include the effect of space charge forces in the electron beam. This model allows us to look at how traveling-wave tube (TWT) performance is affected by random fabrication errors, which are modeled as random perturbations of the phase velocity, interaction impedance, and loss along the TWT´s length. In particular, we examine the effect on TWT gain and instantaneous 1-dB bandwidth. Random variation of the phase velocity is found to have the largest effect on both the gain and bandwidth, but the impact is reduced as the amount of space charge in the beam is increased.

Keywords

travelling wave tubes; 1D small-signal theory; TWT gain; TWT length; TWT performance; finite-space charge electron beams; fundamental forward-wave small-signal bandwidth; fundamental forward-wave small-signal gain; fundamental spatial harmonic mode; instantaneous bandwidth; interaction impedance; phase velocity; random fabrication errors; random perturbations; space charge forces; traveling wave tubes; Bandwidth; Electron beams; Fabrication; Mathematical model; Radio frequency; Space charge; Standards; Fabrication error; manufacturing tolerance; space charge; traveling-wave tube (TWT);

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2012.2236331

Filename

6459576