Traveling-wave tube amplifier model to predict high-order modulation intersymbol interference

In an attempt to develop a more accurate model to correlate intersymbol interference (ISI) with the traveling-wave tube amplifier (TWTA) and the operational signal, a fully three-dimensional (3D), time-dependent, TWT interaction model has been developed using the electromagnetic particle-in-cell (PIC) code MAFIA (Solution of MAxwell's equations by the Finite-Integration-Algorithm). The MAFIA TWT interaction model will be described, and results will be presented where this model was used to investigate the accuracy of the assumptions made in the Signal Processing Workstation (SPW) TWT black-box model.