Theoretical evaluation of nonlinear tapers for a high-power gyrotron

Author

Lawson, Wesley G.

Author_Institution

Lab. for Plasma Res., Maryland Univ., College Park, MD, USA

Volume

38

Issue

11

fYear

1990

fDate

11/1/1990 12:00:00 AM

Firstpage

1617

Lastpage

1622

Abstract

The theoretical performance of two nonlinear circular waveguide tapers constructed for a 10-GHz, 30-MW amplifier utilizing the lowest circular electric mode is evaluated. Mode coupling is estimated with a code that solves the generalized telegraphist´s equations numerically and is compared with the results of a cascaded scattering matrix code. It is found that assuming a sufficiently lossy conducting boundary allows evaluation of modes that pass through cutoff and that consideration of backward modes usually results in small changes in the forward modes that reconcile the two numerical procedures. A comparison of the raised cosine profile with other taper shapes is made. It is shown that, under some conditions, a raised cosine profile yields less mode conversion than the modified Dolph-Chebyshev profile

Keywords

circular waveguides; gyrotrons; waveguide components; waveguide theory; 10 GHz; 30 MW; circular electric mode; circular waveguide; generalized telegraphist´s equations; high-power gyrotron; lossy conducting boundary; microwave amplifier; microwave tubes; mode coupling; modified Dolph-Chebyshev profile; nonlinear tapers; raised cosine profile; Electromagnetic heating; Gyrotrons; High power amplifiers; Production; Scattering; Shape; Tellurium; Transducers; Transmission line matrix methods; Waveguide theory;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.60007

Filename

60007