Effect of circuit fabrication tolerances on the gain and phase of a W-band folded-waveguide TWT
We demonstrate a practical numerical approach to the analysis of the effects of finite fabrication tolerances on the performance of a folded-waveguide TWT. The approach involves the simulation of a numerically generated ‘ensemble’ of TWTs that differ from each other by small random variations in certain key physical circuit dimensions. By computing the ensemble averages and standard deviations of the computed values of various performance metrics (gain, phase, and output power, for example) we can predict the average values and ranges of these and other metrics to be expected in as-built devices. Such studies also can help discover those physical dimensions to which the performance is most sensitive, and therefore can help to optimize a TWT design for maximum performance and/or manufacturing yield.