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IEEE Transactions on Microwave Theory and Techniques
Volume 48 Number 5, May 2000

Table of Contents for this issue

Complete paper in PDF format

The Design of Serpentine-Mode Converters for High-Power Microwave Applications

Wes Lawson, Senior Member, IEEE Melany R. Arjona, Bart P. Hogan and R. L. Ives Senior Member, IEEE

Page 809.

Abstract:

In this paper, we report the design methodology and numerical results for two mode converters that are suitable for high-power microwave applications. Both converters are designed to operate at 11.424 GHz and utilize periodic serpentine structures to convert between modes with different azimuthal-mode indexes. The first converts about 98.5% of an incident linearly polarized TE12 mode to the TE01 mode when oriented as an H-plane bend, but has just 1% mode conversion to all modes when oriented as an E-plane bend. The second device converts a linearly polarized TE11 mode to a TM01 mode with over 99.99% effectiveness. The performance of both devices with respect to parametric variations is detailed. Experimental measurements of the radiation patterns from the TE12-to-TE01-mode converter are consistent with the theoretical predictions.

References

  1. M. Blank, K. Kreischer and R. J. Temkin, "Theoretical and experimental investigation of a quasi-optical mode converter for a 110-GHz gyrotron", IEEE Trans. Plasma Sci., vol. 24, pp.  1058-1066, June  1996.
  2. Z. D. Farkas, "Binary peak power multiplier and its application to linear accelerator design", IEEE Trans. Microwave Theory Tech., vol. MTT-34, pp.  1036-1041, Oct.  1986.
  3. S. G. Tantawi, et al. "A multi-moded RF delay line distribution system for the next linear collider", in Proc. 8th Workshop Advanced Accelerator Concepts, July 1998, pp.  967-974. 
  4. W. G. Lawson, "Theoretical evaluation of nonlinear tapers for a high-power gyrotron", IEEE Trans. Microwave Theory Tech., vol. 38, pp.  1617-1622, Nov.  1990.
  5. W. Lawson, "Theoretical mode conversion in overmoded nonlinear coaxial waveguide tapers", IEEE Trans. Microwave Theory Tech., vol. 42, pp.  127-131, Jan.  1994.
  6. C. Moeller, "Mode converters used in the Doublet III ECH microwave system", Int. J. Electron., vol. 53, pp.  587-593, 1982.
  7. S. P. Morgan, "Theory of curved circular waveguide containing an inhomogeneous dielectric", Bell Syst. Tech. J., vol. 36, pp.  1209-1251, 1957.
  8. E. Luneville, J.-M. Krieg and E. Giguet, "An original approach to mode converter optimum design", IEEE Trans. Microwave Theory Tech., vol. 46, pp.  1-9, Jan.  1998.
  9. J. S. McLean and R. J. Vernon, "A Design for a TE11-to-TE01 serpentine mode converter for a Varian 7.2 GHz Klystron", Univ. Wisconsin, Madison, WI, Int. Rep., Mar. 10, 1992.