Tube Noise under Large Transit-Time Conditions

Abstract

That the noise convection current in a diode would be the same as the noise current in a triode under the conditions θ1≫1 and θ2≪1 (θ1 and θ2 are transit angles in radians of the potential minimum-to-grid and grid-to-plate regions, respectively) is shown by following the approach indicated by Rack and applying the Llewellyn-Peterson small signal theory to study the noise in a triode. Although the general trend of the experimental results agrees very well with the prediction from the Rack approach, the measured value of noise power is found to be about 2 db below the predicted value. The experimental results are applicable to triodes as well under certain conditions.

Noise transport in the crossed-field diode

“…Cutler and Quate (1950), by measuring the noise in an electron beam with a moving cavity, showed the validity of the L-P transformation from the potential minimum input plane to an exit plane located a large transit angle away. Yadavalli (1953) verified the medium transit angle validity of the current coefficients in the L-P approach to the space-charge-limited diode. Thus the L-P transformation equations have gained wide acceptance for the treatment of noise problems in the "O t -type electron beams.…”

Impossible Behavior of Nonlinear Networks

“…General Electric Microwave Laboratory at Stanford, Palo Alto, Californiat (Received July 8,1954) In practice one calculates the noise figure of an electron device by the Rack-Llewellyn-Peterson method. In this method one uses the fluctuations in current and velocity at the entrance plane as the input quantities.…”

“…Quite re- cently Watkins,7 Pierce, 8 and also the authorD employing different techniques have demonstrated that the assumption of lack of correlation between velocity and current fluctuations leads to a valid result in the problem of noise in a temperature limited electron beam in a drift space. It is desired to discuss below such a correlation.…”