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Field Theory of Travelling-Wave with Loss: Application to the Study of Attenuator Saturation Effects


Buchman, William W. (1956) Field Theory of Travelling-Wave with Loss: Application to the Study of Attenuator Saturation Effects. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/F74C-PD63.


NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Propagation constants have been calculated for a lossy traveling-wave tube by means of a field theory. These results have been applied to the prediction of an attenuator power loss of the order of 2 or 3 db. compared to attenuatorless operation. It is shown that the gain of the higher order modes is negligible. Admittance matching by means of radial admittance transformation is the underlying method used throughout. The Pierce-Fletcher theory in common use at this time is examined in some detail to determine its range of validity. It is found to break down when the ratio of beam to helix radius is almost unity and when [...] is small. Furthermore, it is shown that complex parameters must replace the real ones, Q, K, and C, if one wants to extend the Pierce notation correctly to lossy tubes. Not doing so leads to discrepancies of approximately 10% in the propagation constants calculated here. There is reason to believe that parameters other than those used here will not result in greater discrepancy. The effects of space charge bunching on saturation has been treated. Criteria have been set for determining whether bunching is important or not in determining saturation.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Electrical Engineering, Physics and Mathematics)
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Minor Option:Mathematics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Field, Lester M. (advisor)
  • Gould, Roy Walter (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1956
Record Number:CaltechETD:etd-03182004-155923
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:996
Deposited By: Imported from ETD-db
Deposited On:19 Mar 2004
Last Modified:10 Jul 2023 22:58

Thesis Files

PDF (Buchman_w_1956.pdf) - Final Version
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