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High-power TE11 and TM11 circular polarizers in oversized waveguides at 70 GHz

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Abstract

Elliptical deformation of oversized, smooth-wall circular waveguides can produce choosable elliptical or circular polarization from a linearly polarized TE11 or TM11 mode used as intermediate linearly polarized modes in TEO1 to HE11 mode conversion sequences in electron cyclotron resonance heating (ECRH) of magnetically confined thermonuclear fusion plasmas with high-power gyrotrons. Mode coupling in elliptically distorted overmoded circular waveguides has been studied theoretically and experimentally in order to optimize TE11 (and TM11) polarizers (I.D.=27.79 mm) for the 1 MW/70 GHz long-pulse (3s) ECRH system on the Garching Stellarator W VII-AS. Coupling coefficients for ellipticity coupling of non-degenerate modes are given (coupled-mode differential equations formalism). The polarization converters essentially consist of smooth-wall circular waveguides which are gradually squeezed. A sine-squared function of the length coordinate is used to get an almost elliptical crosssection in the middle and circular cross sections at both ends. Arbitrary elliptical polarization states can be generated introducing an extremely low level (<<1%) of undesired spurious modes. Well defined differential phase characteristics have been achieved.

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References

  1. W. Kasparek, G.A. Müller, P.G. Schüller, M. Thumm, R. Wilhelm, V. Erckmann, Proc. 14th Symp. on Fusion Technology (SOFT), Avignon, 1986, p. 829 and

  2. W. Kasparek, H. Kumrić, G.A. Müller, P.G. Schüller, M. Thumm, V. Erckmann, Proc. 15th Symp. on Fusion Technology (SOFT), Utrecht, 1988, Contributed Paper B 19.

  3. M. Thumm, Int. J. Electronics61, 1135 (1986) and Int. J. Electronics57, 1225 (1984).

    Google Scholar 

  4. J.L. Doane, Int. J. Electronics61, 1109 (1986).

    Google Scholar 

  5. P.I. Sandsmark, I.R.E. Trans.MTT-3, 15 (1955).

    Google Scholar 

  6. S.P. Morgan, Jr., J. Appl. Phys.21, 329 (1950).

    Google Scholar 

  7. H.E. Rowe and W.D. Warters, Bell Syst. Techn. J.41, 1031 (1962).

    Google Scholar 

  8. M. Thumm and H. Kumrić, Conf. Digest 12 th Int. Conf on Infrared and Millimeter Waves, Lake Buena Vista, Florida, 1987, p. 336.

  9. W. Kasparek and G.A. Müller, Int. J. Electronics64, 5 (1988).

    Google Scholar 

  10. H. Kumrić and M. Thumm Int. J. Infrared and Millimeter Waves7, 1439 (1986).

    Google Scholar 

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Authors and Affiliations

  1. Institut für Plasmaforschung, Universität Stuttgart, D-7000, Stuttgart 80, Federal Republic of Germany

    Manfred Thumm & Helga Kumric

Authors
  1. Manfred Thumm
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  2. Helga Kumric
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Thumm, M., Kumric, H. High-power TE11 and TM11 circular polarizers in oversized waveguides at 70 GHz. Int J Infrared Milli Waves 10, 1059–1075 (1989). https://doi.org/10.1007/BF01010365

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  • DOI: https://doi.org/10.1007/BF01010365

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