Computer simulation of intermodulation distortion in traveling wave tube amplifiers

The intermodulation performance of a helix TWT was computed using a large-signal disc model with two, three and eight correlated carriers and also using the program IMAL which models a generalized nonlinearity described by its single carrier transfer characteristics. The results obtained hv both methods showed good agreement. The inter-modulation performance of a TWT for both correlated and uncorrelated carriers can therefore be predicted from its single-carrier transfer characteristics if they do not change significantly over the frequency range of interest.