A fast largesignal model for coupledcavity TWT's
Abstract
A fast and accurate onedimensional largesignal model for coupledcavity TWTs (travelingwave tubes) that can be used interactively for the optimization of a TWT design is discussed. Different modeling techniques for enhancing the speed of the largesignal model with no loss in accuracy are discussed. It is shown that the speed of the model can be increased by: (1) suitable selection of the basic integration parameters such as the number of electron disks per RF cycle and number of integration steps per cavity; (2) choosing a suitable method of integration of the relativistic equation of motion; (3) optimizing the iteration processes through each cavity and each section, and (4) efficient calculation of the spacecharge forces. The model has been tested for the lowspacecharge highefficiency NASA CTS 200W tube and for a highspacecharge highgain tube. The characteristics of a 58cavity tube for a single value of input power and frequency can be computed in less than 1.5 min of CPU time on a VAX 11/785 computer. This at least 5 to 6 times faster than the previous models with the same accuracy.
 Publication:

IEEE Transactions on Electron Devices
 Pub Date:
 November 1988
 DOI:
 10.1109/16.7429
 Bibcode:
 1988ITED...35.2068S
 Keywords:

 Computer Techniques;
 Coupled Modes;
 Microwave Amplifiers;
 Signal Analysis;
 Traveling Wave Tubes;
 Cavities;
 Electron Beams;
 Iterative Solution;
 Vax Computers;
 Electronics and Electrical Engineering