Computer simulation of intermodulation distortion in traveling wave tube amplifiers

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