Advertisement

High Frequency Em Scattering by Non-Uniform Open Waveguide Cavities Containing an Interior Obstacle

  • P. H. Pathak
  • P. H. Law
  • R. J. Burkholder
Chapter

Abstract

An analysis of the high frequency (HF) electromagnetic scattering by an open waveguide cavity containing a complex interior obstacle is of interest in scattered field and electromagnetic coupling predictions. A typical cavity-obstacle geometry is shown in Figure 1; this geometry is illuminated by an external source. The interior walls of the cavity are assumed to be perfectly conducting but may contain a thin material coating. The HF scattering by the configuration in Figure 1 is analyzed here primarily for the case when the observation point lies on the same side of the scattering geometry as the source, and for incidence and scattering angles within about 75° from the axis of the waveguide at the open front end. Outside of this region the scattering by external features of the cavity are generally more dominant than the scattering from the cavity interior. The method of analysis described here is based on a hybrid combination of HF ray/beam techniques, or modal techniques (mostly for cavities built up by connecting separable waveguide sections), with other methods. The HF techniques, or the modal techniques, are used to track the fields coupled into the waveguide cavity; whereas, other (numerical or experimental) methods are required in general to deal with the effect of the complex interior obstacle.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    J.B. Keller, Geometrical theory of diffraction, Journal Opt. Soc. Am. 52:116–130 (1962).ADSCrossRefGoogle Scholar
  2. [2]
    R.G. Kouyoumjian and P.H. Pathak, “A UTD Approach to EM Scattering and Radiation,” Chapter 3 in Low and High Frequency Asymptotics, V.K. Varadan and V.V. Varadan, eds., North-Holland, Elsevier Science Publishers, B.V. Netherlands (1986).Google Scholar
  3. [3]
    P.H. Pathak, “Techniques for high frequency problems,” in Antenna Handbook — Theory, Applications, and Design, Van Nostrand Reinhold, New York (1988).Google Scholar
  4. [4]
    P. Ya. Ufimtsev, Method of edge waves in the physical theory of diffraction, (from the Russian, Method krayevykh voin v fizicheskoy teoril difraktsii), Izd-Vo Sov. Radio 1–243 (1962). Translation prepared by the U.S. Air Force Foreign Technology Division, Wright-Patterson Air Force Base, OH; released for public distribution September 7, 1971.Google Scholar
  5. [5]
    P.H. Pathak and R.J. Burkholder, “Modal, Ray and Beam Techniques for Analyzing the EM Scattering by Open-ended Waveguide Cavities, IEEE Trans. Antennas Prop. Vol. AP-37, No. 5, pp. 635–647, May 1989.ADSCrossRefGoogle Scholar
  6. [6]
    R.J. Burkholder, “High-Frequency Asymptotic Methods for Analyzing the EM Scattering by Open-Ended Waveguide Cavities,” Ph.D. Dissertation, The Ohio State University, Columbus, June 1989.Google Scholar
  7. [7]
    A. Altintas, P.H. Pathak, and M.C. Liang, “A Selective Modal Scheme for the Analysis of EM Coupling into or Radiation from Large Open-Ended Waveguides,” IEEE Trans. Antennas Prop. Vol. AP-36, No. 1, pp. 84–96, January 1988.ADSCrossRefGoogle Scholar
  8. [8]
    I.I. Shirai and L.B. Felsen, “Rays, Modes and Beams for Plane Wave Coupling into a Wide Open-Ended Parallel-Plane Waveguide,” Wave Motion, 9, pp. 301–317, 1987.CrossRefGoogle Scholar
  9. [9]
    I.I. Shirai and L.B. Felsen, “Rays and Modes for Plane Wave Coupling into a Large Open-Ended Circular Waveguide,” Wave Motion, 9, pp. 461–482, 1987.CrossRefGoogle Scholar
  10. [10]
    S.W. Lee, I.I. Ling and R.-C. Chou, “Ray-Tube Integration in Shooting and Bouncing Ray Method,” Microwave and Optical Tech. Letters, Vol. 1, No. 8, October 1988.CrossRefGoogle Scholar
  11. [11]
    I.I. Ling, R.-C. Chou, and S.W. Lee, “Shooting and Bouncing Rays: Calculating the RCS of an Arbitray Cavity,” IEEE Trans. Antennas and Prop. Vol. AP-37, No. 2, pp. 194–205, February 1989.ADSCrossRefGoogle Scholar
  12. [12]
    J. Maciel and L.B. Felsen, “Systematic Study of Fields Due to Extended Apertures by Gaussian Beam Discretization,” IEEE Trans. Antennas and Prop. Vol. AP-37, No. 7, pp. 884–892, July 1989.ADSCrossRefGoogle Scholar
  13. [13]
    J. Maciel and L.B. Felsen, “Gaussian Beam Analysis of Propagation from an Extended Plane Aperture Distribution Through Dielectric Layers, Part I - Plane Layer, Part II — Circular Cylindrical Layer,” IEEE Trans. Antennas and Prop. Vol. AP-38, No. 10, pp. 1607–1624, October 1990.ADSCrossRefGoogle Scholar
  14. [14]
    P.H. Pathak and R.J. Burkholder, “High Frequency EM Scattering by Open-Ended Waveguide Cavities,” accepted for publication in J. Radio Science, Jan.-Feb. 1991.Google Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • P. H. Pathak
    • 1
  • P. H. Law
    • 1
  • R. J. Burkholder
    • 1
  1. 1.ElectroScience LaboratoryThe Ohio State UniversityColumbusUSA

Personalised recommendations