학술논문
Absolute instability at the band edges in linear beam traveling wave tubes
Document Type
Conference
Author
Source
2015 IEEE International Vacuum Electronics Conference (IVEC) Vacuum Electronics Conference (IVEC), 2015 IEEE International. :1-2 Apr, 2015
Subject
Language
Abstract
We use the Briggs-Bers criterion to examine the absolute instability at the lower and upper band edges of a coupled cavity TWT. We find that the lower band-edge is not subjected to absolute instability. At the upper band-edge, we find a threshold beam current beyond which absolute instability is excited. In general, an absolute instability would occur in a linear beam tube if the cold-tube circuit dispersion curve in the frequency-wavenumber (ω-k) plane is locally convex, and would not occur if the cold circuit dispersion curve is locally concave.