Investigation of the Uses of Time Domain Capable Vector Network Analyzers as a Diagnostic for Helix Traveling-Wave Circuits

摘要

The purpose of this project is to investigate the uses of time domain capable vector network analyzers as diagnostics for the design and test of helix traveling-wave tubes (TWT's). The uses of the time domain (TD) investigated included tracking the location of a bead in the circuit, determining the phase velocity versus frequency using the gating methods available in the time domain, and locating faults and discontinuities along the helix circuit. Good agreement with expected results were obtained for the phase velocity versus frequency in a 2-8 GHz circuit, except at the band edges, and uses for fault location were demonstrated. Another method was devised using the complex nature of the data without going into the time domain to measure phase velocity versus frequency data. This method proved to be more accurate overall than the time domain method.