High power traveling-wave tube gain and saturation characteristics as a function of attenuator configuration and resistivity

The attenuator is a common and important component of every traveling — wave tube which uses a bi-directionally propagating slow-wave structure. There are several types of attenuators suitable for traveling-wave tube use and many aspects of each type. This paper is concerned only with distributed attenuators suitable for application in high-power, helix-type traveling-wave tubes and presents experimental evidence that there are three parameters, (a) loss, (b) circuit impedance, and (c) circuit phase velocity, needed to adequately describe the attenuator section.