ISSN:
1420-9039
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mathematics
,
Physics
Notes:
Summary The travelling-wave tube (T. W. T.) is recomputed by means of an equivalent circuit giving the characteristic impedance for purposes of comparison with the klystron and the triode. With the klystron and the T. W. T. a shot effect is induced in the amplifier input, but not with the triode, so that increasing the transconductance of the two former tubes does not result in a reduction of the noise figure as with the triode. For the same beam current the noise figure of the T. W. T. and the klystron are approximately the same. The T. W. T. is, however, superior to the klystron in that, for the same beam length, the gain is greater, due to the fact that it increases exponentially for the former and linearly for the klystron. It is therefore concluded that it should be possible considerably to improve the signal-to-noise ratio of the klystron-type of amplifier by suitably increasing the beam length (e. g. by magnetic means). An advantage accruing would be that the input and output are decoupled; in the case of the T. W. T. this leads to oscillation if the helix is not matched so as to avoid reflections.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02020067
Permalink
