Impedance Properties of Electron Streams

Abstract

The input impedance of an idealized space charge grid tube is investigated under general conditions of space charge between the accelerating grid and the negatively biased control grid. It is shown that under certain space charge conditions the input capacitance and conductance both may be negative. These impedance properties persist up to frequencies for which the transit angle is quite large. Possibilities of designing electronic negative capacitances are thus opened up. Experimental results are also given; these give a broad confirmation of the theoretical deductions.