volume | PIER Journals

Abstract

A rigorous field-theoretic method of analyzing the large-signal behavior of a linear beam traveling wave tube amplifier (TWTA) with slow-wave structure modeled to be a dielectric-loaded sheath helix is presented. The key step in the analysis is a representation of the field components as nonlinear functionals of the electron arrival time through a Green's function sequence for the slow-wave circuit. Substitution of this functional representation for the axial electric field component into the electron ballistic equation casts the latter into a fixed point format for a nonlinear operator in an appropriate function space. The fixed point, and therefore the solution for the electron-arrival time and hence the solution for the electromagnetic field components, can be obtained by standard successive approximation techniques. The calculations of the gain, the efficiency and the other amplifier parameters, comparison of the results of the present theory with experimental results etc., on the basis of such a successive approximation solution for the field components, will be presented in the second part of this paper.

1. Pierce, J. R. and L. M. Field, "Traveling wave tubes," Proc. IRE, Vol. 35, 108-111, 1947.
doi:10.1109/JRPROC.1947.226216 Google Scholar

2. Pierce, J. R., "Theory of the beam-type traveling wave tube," Proc. IRE, Vol. 35, 111-123, 1947.
doi:10.1109/JRPROC.1947.226217 Google Scholar

3. Kompfner, R., "The traveling wave tube as amplifier at microwaves," Proc. IRE, Vol. 35, 124-128, 1947.
doi:10.1109/JRPROC.1947.231238 Google Scholar

4. Rydbeck, O. E. H., "Theory of the traveling wave tubes," Ericsson Technics, Vol. 46, 3-18, 1948. Google Scholar

5. Chu, L. J. and J. D. Jackson, "Field theory of traveling wave tubes," Proc. IRE, Vol. 36, 853-863, 1948.
doi:10.1109/JRPROC.1948.230932 Google Scholar

6. Collin, R. E., Foundations for Microwave Engineering, 2nd Ed., IEEE Press, 2005.

7. Rowe, J. E., Nonlinear Electron-wave Interaction Phenomena, Academic Press, 1965.

8. Freund, H. P., M. A. Kodis, and N. R. Vanderplaats, "Design of traveling wave tubes based on field theory," IEEE Trans. on Electron Devices, Vol. 41, No. 7, 1288-1296, 1994.
doi:10.1109/16.293360 Google Scholar

9. Freund, H. P., E. G. Zaidman, M. A. Kodis, and N. R. Vanderplaats, "Linearized field theory of a dielectric-loaded helix traveling wave tube amplifier," IEEE Trans. on Plasma Science, Vol. 24, No. 3, 895-904, 1996.
doi:10.1109/27.533093 Google Scholar

10. Detweiler, H. K. and J. E. Rowe, "Electron dynamics and energy conversion in O-type linear beam devices," Advances in Microwaves, Vol. 6, 29-123, 1971. Google Scholar

11. Kalyanasundaram, N., "Large signal field analysis of an O-type traveling wave amplifier. Part 1: Theory," IEE Proc. I, Solid-State & Electron Dev., Vol. 131, No. 5, 145-152, 1984.
doi:10.1049/ip-i-1.1984.0040 Google Scholar

12. Kalyanasundaram, N. and R. Chinnadurai, "Large signal field analysis of an O-type traveling wave amplifier. Part 2: Numerical results," IEE Proc. I, Solid-State & Electron Dev., Vol. 133, No. 4, 163-168, 1986.
doi:10.1049/ip-i-1.1986.0031 Google Scholar

13. Kalyanasundaram, N. and R. Chinnadurai, "Large signal field analysis of an O-type traveling wave ampli¯er. Part 3: Three-dimensional electron motion," IEE Proc. I, Solid-State & Electron Dev., Vol. 135, No. 3, 59-66, 1988.
doi:10.1049/ip-i-1.1988.0011 Google Scholar

14. Jain, P. K. and B. N. Basu, "The Inhomogeneous loading effects of practical dielectric supports for the helical slow-wave structure of a TWT," IEEE Trans. on Electron Devices, Vol. 34, No. 12, 2643-2648, 1987.
doi:10.1109/T-ED.1987.23366 Google Scholar

15. Gewartowski, J. W. and H. A. Watson, Principles of Electron Tubes, 1968.

16. Naylor, A. W. and G. R. Sell, Linear Operator Theory in Engineering and Science, Springer-Verlag, 1982.
doi:10.1007/978-1-4612-5773-8

17. Agnihotri, A., "Large-signal field analysis of a linear beam traveling wave amplifier for a dielectric-loaded sheath helix model of the slow-wave structure," Forthcoming Ph.D. Dissertation, Jaypee Institute of Information Technology, 2014. Google Scholar

18. Thomas, J. B., Introduction to Probability, Springer-Verlag, 1986.
doi:10.1007/978-1-4613-8658-2

19. Jacod, J. and P. Protter, "Probability Essentials," Springer, 2003. Google Scholar

20. Kalyanasundaram, N. and G. N. Babu, "Propagation of electromagnetic waves guided by anisotropically conducting model of a tape helix supported by dielectric rods," Progress In Electromagnetics Research B, Vol. 51, 81-99, 2013. Google Scholar

Prof. Natarajan Kalyanasundaram

Dr. Amita Agnihotri