Some experiments on the effect of a circuit sever on high-power travelling-wave tube efficiency

Abstract

In order to avoid an excessive amount of feedback in a high gain travelling wave amplifier, caused by internal reflections, sone form of r.f. isolation in the slow-wave structure is needed. In high power tubes such isolation is usually provided by introducing one or more breaks, or severs, in the structure. At these severs any circuit power is dissipated in resistive loads and the signal is propagated solely as current and velocity modulations on the electron beam.