A Computerized System for the Measurement of Attenuation in a Helix Waveguide

A computer controlled system for fast and accurate measurements of the TEo11, TEo12 mode attenuations in a helix waveguide over the frequency range of 85-110 GHz is described. Measurement is done by monitoring the change in amplitude of a 10-ns wide pulse propagating inside the helix, as a function of the position of a moving short circuiting piston. Data are acquired and processed by a mini-computer facility. A brief discussion on the generation of the desired waveguide modes and the results of some typical measurements are also given.