Parametric Simulation and Optimization of Cold-test Properties for a 220 GHz Broadband Folded Waveguide Traveling-wave Tube

  • Ruilin Zheng
  • Xuyuan Chen


Characterized with full-metal structure, high output power and broad bandwidth, microfabricated folded waveguide is considered as a robust slow-wave structure for millimeter wave traveling-wave tubes. In this paper, cold-test (without considering the real electron beam) properties were studied and optimized by 3D simulation on slow-wave structure, for designing a 220 GHz folded waveguide traveling-wave tube. The parametric analysis on cold-test properties, i.e., phase velocity, beam-wave interaction impedance and cold circuit attenuation, were conducted in half-period circuit with high frequency structure simulator, assisted by analytical model and equivalent circuit model. Through detailed parametric analyses, interference between specified structural parameters is found on determining beam-wave interaction impedance. A discretized matrix optimization for interaction impedance was effectively carried out to overcome the interference. A range of structural parameters with optimized interaction impedance distributions were obtained. Based on the optimized results, a broadband folded waveguide with cold pass-band of about 80 GHz, flat phase velocity dispersion and fairly high interaction impedance was designed for a 220 GHz central frequency traveling-wave tube. A three-dB bandwidth of 20.5 GHz and a maximum gain of 21.2 dB were predicted by small signal analysis for a 28 mm-long lossy circuit.


Folded waveguide Traveling-wave tubes Cold-test properties Simulation Optimization 


  1. 1.
    R. K. Parker, R. H. Abrams Jr., B. G. Danly, and B. Levush, “Vacuum electronics,”. IEEE Transactions on Microwave Theory and Techniques 50(3), 835–844 (2002).CrossRefGoogle Scholar
  2. 2.
    V. L. Granatstein, R. K. Parker, and C. M. Armstrong, “Scanning the technology: vacuum electronics at the dawm of twenty-first century,”. Proceedings of the IEEE 87(5), 702–716 (1999).CrossRefGoogle Scholar
  3. 3.
    J. H. Booske, M. C. Converse, C. L. Kory, C. T. Chevalier, D. A. Gallagher, K. E. Kreisher et al., “Accurate parametric modeling of folded waveguide circuits for millimeter-wave traveling wave tubes,”. IEEE Transactions on Electron Devices 52(5), 685–694 (2005).CrossRefGoogle Scholar
  4. 4.
    R. L. Ives, “Microfabrication of high-frequency vacuum electron devices,”. IEEE Transactions on Plasma Science Vol.32, Issue3, Part1, 1277–1291 (2004).CrossRefGoogle Scholar
  5. 5.
    G. Doher, D. Gagne, D. Gallagher, R. Moats, “Serpentine waveguide TWT,” International Electron Devices Meeting, Technical Digest, pp. 485–488 (1987).Google Scholar
  6. 6.
    H. -J. Ha, S. -S. Jung, and G. -S. Park, “Theoretical study for folded waveguide traveling wave tube,”. International Journal of Infrared and Millimeter Waves 19(9), 1229–1245 (1998).CrossRefGoogle Scholar
  7. 7.
    S. Liu, “Study of propagation characteristics for folded waveguide TWT in millimeter wave,”. International Journal of Infrared and Millimeter Waves 21(4), 655–660 (2000).CrossRefGoogle Scholar
  8. 8.
    S. -T. Han, J. -I. Kim, and G. -S. Park, “Design of a folded waveguide traveling-wave tube,”. Microwave and Optical Technology Letters 38(2), 161–165 (2003).CrossRefGoogle Scholar
  9. 9.
    H. Essen, A. Wahlen, R. Sommer, W. Johannes, R. Brauns, M. Schlechtweg and A. Tessmann, “High bandwidth 220 GHz experimental radar,” Electronic Letters Vol.43, No.20, pp.1114–1116, (2007).Google Scholar
  10. 10.
    N. Marcuvitz, “Waveguide Handbook”, Peter Peregrinus Ltd, 1986, pp.333–334, 364–365.Google Scholar
  11. 11.
    B. N.Basu, “Electromagnetic theory and applications in beam-wave electronics”, World scientific, (1996).Google Scholar
  12. 12.
    S. Liu, H. li, W. Wang and Y. Mo, “Introduction to microwave electronics”, National defense industry press, 1985 (in Chinese).Google Scholar
  13. 13.
    D. M. Pozar, “Microwave engineering (second edition)”,Wiley, 1998, pp. 94–95.Google Scholar
  14. 14.
    Ansoft HFSS online help v10.Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Institute for Microsystem TechnologyVestfold University CollegeBorreNorway
  2. 2.Pen-Tung Sah MEMS Research CenterXiamen UniversityXiamenChina

Personalised recommendations