A fast large-signal model for coupled-cavity TWT's
Abstract
A fast and accurate one-dimensional large-signal model for coupled-cavity TWTs (traveling-wave tubes) that can be used interactively for the optimization of a TWT design is discussed. Different modeling techniques for enhancing the speed of the large-signal 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 space-charge forces. The model has been tested for the low-space-charge high-efficiency NASA CTS 200-W tube and for a high-space-charge high-gain tube. The characteristics of a 58-cavity 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