Filter helix for harmonic suppression in traveling wave tubes

Publikationstyp
Journal Article
Date Issued
2014-06
Sprache
English
Author(s)
Gehrmann, Elke  
Birtel, Philip  
Dürr, Wolfgang  
Jacob, Arne F.  
Institut
Hochfrequenztechnik E-3  
TORE-URI
http://hdl.handle.net/11420/8393
Journal
IEEE transactions on electron devices  
Volume
61
Issue
6
Start Page
1859
End Page
1864
Article Number
6719490
Citation
IEEE Transactions on Electron Devices 6 (61): 6719490 (2014)
Publisher DOI
10.1109/TED.2013.2296150
Scopus ID
2-s2.0-84901358279
Increasing the efficiency of traveling wave tubes (TWTs) is a basic development strategy. In this paper, second harmonic suppression is introduced as a possible mean. For this purpose, a filter consisting of periodic pitch discontinuities is implemented in the helix transmission line (TL) of a tube. A method is developed to obtain the reflection coefficients of adjustable pitch discontinuities. A filter design for a low frequency TWT is tested in a helical TL without electron beam and implemented in the tube. Both simulation and measurement confirm a stopband at the second harmonic and thus a significant reduction of this harmonic at the output. An additional filter is designed and tested at S-band. It is shown to improve both the output power and the linearity of the tube.
Subjects
Efficiency
filter
harmonic
reflections
traveling wave tube (TWT)
DDC Class
000: Allgemeines, Wissenschaft