• M.Thottappan
  • Surya Prakash Singh
  • P.K.Jain



Gyrotron, traveling wave tube amplifier, large signal analysis, Phase bunching, electromagnetic PIC simulation


The analysis of a Ka-band gyrotron Travelling Wave Tube (gyro-TWT) amplifier using a uniform cylindrical waveguide as its interaction circuit has been presented for the TE01 mode of operation a self-consistent nonlinear analysis in the large signal regime. The analysis predicts that the saturated peak output power of ~ 134 kW with a power conversion efficiency of ~ 22.7 %. The saturated gain has been calculated as ~ 41.3 dB for the amplifier driven by 72 kV, 8.2 A electron beam of a pitch factor 1.05. The critical interaction length of smooth wall uniform metal guide is found 10.7 cm for the stable amplifier operation. The form factor and the norm factor have also been estimated with the large signal non-linear code. Further, for 5% spread the amplifier develops the peak power of ~ 128 kW with an electronic efficiency of ~ 21.7 % and the gain of ~ 41.07 dB. These results are found to be good harmony when the beam wave interaction is studied with a commercial 3-D electromagnetic particle in cell (PIC) code. The behaviour of the beam all over the length of the interaction circuit has been monitored by calculating its energy, momentum, phase, etc. with the help of a commercial PIC code and which also in good agreement with analytical results with 1% deviation.


[1] K. R. Chu, “The electron cyclotron maser,” Review of Modern Physics, vol. 76, no. 2, pp. 489-540, Apr. 2004.
[2] G. S. Nusinovich, “Non-Linear Theory of the gyro-TWT,” in Introduction to the physics of gyrotrons, Baltimore and
London: John Hopkins University Press, 2004.
[3] Chao-Hai Du and Pu-Kun Liu, “Nonlinear full-wave-interaction analysis of a gyrotron-traveling-wave-tube amplifier
based on a lossy dielectric-lined circuit,” phys. of plasmas, vol. 17, 033104, 2010.
[4] Oleksandr V. Sinitsyn, Gregory S. Nusinovich, Khanh T. Nguyen, and Victor L. Granatstein, “Nonlinear Theory of the
gyro-TWT: Comparison of Analytical Method and Numerical Code Data for the NRL gyro-TWT”, IEEE Transactions
on Plasma Science, vol. 30, no. 3, Jun. 2002.
[5] P. Sprangle and A. T. Drobot, “The linear and self-consistent nonlinear theory of the electron cyclotron maser
instability,” IEEE Trans. Microwave Theory Tech., vol. MTT-25, pp. 528–544, June 1977.
[6] K. R. Chu, A. T. Drobot, V. L. Granatstein, and J. L. Seftor, “Characteristics and optimum operating parameters of a
gyrotron traveling-wave amplifier,” IEEE Trans. Microwave Theory Tech., vol. MTT-27, pp. 178–187, Feb. 1979.
[7] K. R. Chu, A. T. Drobot, H. H. Szu, and P. Sprangle, “Theory and simulation of the gyrotron traveling wave amplifier
operating at cyclotron harmonics,” IEEE Trans. Microwave Theory Tech., vol. MTT-28, pp. 313–317, Apr. 1980.
[8] N. S. Ginzburg, I. G. Zarnitsyna, and G. S. Nusinovich, “Theory of relativistic CRM amplifiers,” Radiophys. Quantum
Electron., vol. 24, pp. 331–338, 1981.
[9] V. L. Bratman, N. S. Ginzburg, G. S. Nusinovich, M. I. Petelin, and P. S. Strelkov, “Relativistic gyrotrons and
cyclotron autoresonance masers,” Int. J. Electron., vol. 51, pp. 541–568, 1981.
[10] A. W. Fliflet, “Linear and nonlinear theory of the Doppler-shifted cyclotron resonance maser based on TE and TM
waveguide modes,” Int. J. Electron., vol. 61, pp. 1049–1080, 1986.
[11] J. L. Seftor, V. L. Granatstein, K. R. Chu. “The electron cyclotron cyclotron maser as a high power traveling-wave
amplifier of millimeter waves,” IEEE J. Quantum Electron, vol. 15, no. 2, pp. 848–853, 1979.
[12] L. R. Barnett, J. M. Baird, Y. Y. Lau, et al. “A high gain single stage gyrotron traveling wave amplifier,” IEDM Tech.
Dig., vol. 1, no. 2, pp. 314–317, 1980.
[13] R. S. Symons, H. R. Jory, J. Hegji, and P. E. Ferguson, “An experimental Gyro-TWT,” IEEE Trans. Microwave Theory
Tech. vol. MTT-29, pp. 181–184, 1981.
[14] Patrick E. Fergusion, Gerald Valier, and Robert S. Symons. “Gyrotron-TWT Operating Characteristics,” IEEE. Trans.
Microwave Theory Tech. vol. MTT-29 no. 8, pp.794–799 , 1981.
[15] K. R. Chu, L. R. Barnett, W. K. Lau, et al. “A wide-band millimeter-wave gyrotron traveling-wave amplifier
experiment,” IEEE Trans. Electron Devices, vol. 37, no. 2, pp. 1557–1560, 1990.
[16] K. R. Chu, L. R. Barnett, W. K. Lau, et al. “Recent development in millimeter wave gyro-TWT research at NTHU,”
IEDM Tech. Dig., vol. 1, no. 1, pp. 699–702, 1990.
[17] K. R. Chu, L. R. Barnett, H. Y. Chen, S. H. Chen, C. Wang, Y. S. Yeh, Y. C. Tsai, T. T. Yang, and T. Y. Dawn,
“Stabilization of absolute instabilities in the gyrotron traveling wave amplifier,” Phys. Rev. Lett., vol. 74, pp. 1103–
1106, 1995.
[18] K. R. Chu, H. Y. Chen, C. L. Hung, et al. “Theory and experiment of ultrahigh gain gyrotron travelingwave amplifier,”
IEEE Trans. Plasma. Sci., vol. 27, no. 2, 391–404, 1999.
[19] K. T. Nguyen, J. P. Calame, D. E. Pershing, B. G. Danly, M. Garven, B. Levush, and T. M. Antonsen, “Design of Kaband gyro-TWT for radar applications,” IEEE Trans. Plasma. Sci., vol. 48, pp. 108–115, Jan.2001
[20] M. Garven, J. P. Calame, B. G. Danly, K. T. Nguyen, B. Levush, F. N. Wood, and D. E. Pershing, “Experimental
studies of a gyro-TWT amplifier with a lossy ceramic interaction region,” IEEE Trans. Plasma Sci., vol. 30, pp. 885–
893, 2002.
[21] K. T. Nguyen, J. P. Calame, D. E. Pershing, B. G. Danly, M. Garven,B. Levush, and T.M. Antonsen Jr., “Design of a
Ka-band gyro-TWT for radar applications,” IEEE Trans. Electron Devices, vol. 48, pp. 108–115, Jan. 2001.
[22] Reddy, S. U. M., V. B. Naidu, S. K. Datta, P. K. Jain, and L. Kumar, “PIC simulation of a gyrotron-traveling-wave tube
amplifier,” IEEE Int. Conf. (IVEC), pp. 319-320, 2010.
[23] Shou-Xi Xu, Pu-Kun Liu, Shi-Chang Zhang, Chao-Hai Du, Qian-Zhong Xue, Zhi-Hui Geng, and Yi-Nong Su, “Particle
simulation of a ka-band gyrotron traveling wave amplifier,” phys. of plasmas, vol. 18, 083501, 2011.
[24] J. R. Sirigiri, “Theory and Design Study of a Novel Quasi-Optical gyrotron Traveling Wave Amplifier,” M.S Thesis,
Dept. of Electr. Engg. and Comp. Sci., MIT, USA, 1999.
[25] CST-Particle Studio, User's Manual, Darmstadt, Germany, 2012.
[26] U. Singh y, N. Kumar, N. Kumar, S. Tandon, H. Khatun, L. P. Purohit, and A. K. Sinha, “Numerical simulation of
magnetron injection gun for 1 MW, 120 GHz gyrotron,” PIER Letters, vol. 16, pp. 21-34, 2010.




How to Cite

M.Thottappan, Surya Prakash Singh, & P.K.Jain. (2013). ANALYSIS AND PIC SIMULATION OF A GYROTRON TRAVELLING WAVE TUBE AMPLIFIER. Journal of Microwaves, Optoelectronics and Electromagnetic Applications (JMOe), 12(2), 307-324.



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