volume | PIER Journals

2007-01-31

Effect of Internal Resonance on the Radar Cross Section and Shield Effectiveness of Open Spherical Enclosures

Khalid Fawzy Ahmed Hussein

Professor Khalid Fawzy Ahmed Hussein

Microwave Engineering Department

Electronics Research Institute

Egypt

Homepage

Progress In Electromagnetics Research, Vol. 70, 225-246, 2007

doi:10.2528/PIER07012101 | Google Scholar

Abstract

In this paper, the effects of the internal resonances of an open conducting spherical enclosure with circular aperture on its radar cross section (RCS) and shield effectiveness (SE) are studied over a wide frequency band. The sizes of the spherical enclosures investigated in the present work range from electrically small (perimeter is less than the wavelength) to electrically large (perimeter is up to ten times the wavelength). It is shown that for such an enclosure, both the RCS and SE, as functions of frequency, have sharp spikes, minima, or maxima at the resonant frequencies corresponding to the internal modes of the closed conducting sphere. Principal and higher order modes are considered. The effects of the aperture width on the perturbation of the field inside and outside of the spherical enclosure, the near field outside the cavity, the RCS and the SE are presented over a wide range of frequency. It is shown that the sharpness and amplitude of the spikes, minima, or maxima of the RCS and SE are decreased with increasing the aperture width. Also, the resonant frequencies of the enclosed spherical cavity are shifted with increasing the aperture width. For the purpose of verifying the accuracy of the obtained results for the SE of an open spherical enclosure at resonance, the obtained field configurations and distributions inside a spherical enclosure of a small aperture are compared to those of the spherical cavity modes which have already been obtained analytically. Also, some of the results concerning the RCS of a spherical enclosure are compared to other published results.

Download Full Article (344) View Full Article volume

Citation

Copy Export

Khalid Fawzy Ahmed Hussein, "Effect of Internal Resonance on the Radar Cross Section and Shield Effectiveness of Open Spherical Enclosures," Progress In Electromagnetics Research, Vol. 70, 225-246, 2007.
doi:10.2528/PIER07012101

References

1. Ammari, H., G. Bao, and A. W. Woods, "A cavity problem for Maxwell's equations," Methods and Applications of Analysis, Vol. 9, No. 2, 249-260, 2002. Google Scholar

2. Jin, J. M. and J. L. Volakis, "A finite element-boundary integral formulation for scattering by three-dimensional cavity-backed apertures," IEEE Trans. Antennas and Prop., Vol. AP-39, No. 1, 97-104, 1991.
doi:10.1109/8.64442 Google Scholar

3. Alfonzetti, S., B. Azzerboni, and G. Borzi, "Scattering from threedimensional cavity-backed apertures in infinite ground plane by RBCI," IEEE Trans. Magnetics, Vol. 36, No. 7, 917-920, 2000.
doi:10.1109/20.877592 Google Scholar

4. Vinogradov, S. S., P. D. Smith, and E. D. Vinogradova, Canonical Problems in Scattering and Potential Theory, Part I: Canonical structures in potential theory, 2002.

5. Rao, S. M., D. R. Wilton, and A. W. Glisson, "Electromagnetic scattering by surfaces of arbitrary shape," IEEE Trans. Antennas Propagat., Vol. 30, No. 5, 409-418, 1982.
doi:10.1109/TAP.1982.1142818 Google Scholar

6. Yla-Oijala, P., M. Taskinen, and J. Sarvas, "Surface integral equation method for general composite material and dielectric structures with junctions," Progress In Electromagnetics Research, Vol. 52, 81-108, 2005.
doi:10.2528/PIER04071301 Google Scholar

7. Hanninen, I., M. Taskinen, and J. Sarvas, "Singularity subtraction integral formulae for surface integral equations with RWG, rooftop and hybrid basis functions," Progress In Electromagnetics Research, Vol. 63, 243-278, 2006.
doi:10.2528/PIER06051901 Google Scholar

8. Kotsis, A. D. and J. A. Roumeliotis, "Electromagnetic scattering by a metallic spheroid using shape perturbation method," Progress In Electromagnetics Research, Vol. 67, 113-134, 2007.
doi:10.2528/PIER06080202 Google Scholar

9. Mallahzadeh, A. R. and M. Soleimani, "RCS computation of airplane using parabolic equation," Progress In Electromagnetics Research, Vol. 57, 265-276, 2006.
doi:10.2528/PIER05080101 Google Scholar

10. Khan, Z. A., C. F. Bunting, and M. D. Deshpande, "Shielding effectiveness of metallic enclosures at oblique and arbitrary polarizations," IEEE Trans. Elctromagn. Compat., Vol. 47, No. 1, 2005. Google Scholar

11. Starton, J. A., Electromagnetics Theory, Section 9.24, 1941.

12. Abramowitz, M. and I. Segun, Handbookof Mathematical Functions with Formulas, Graphs, 1965.

13. Hussein, K. F. A., "Fast computational algorithm for EFIE applied to arbitrarily-shaped conducting surfaces," Progress In Electromagnetics Research, Vol. 68, 339-357, 2007. Google Scholar

14. Hussein, K. F. A., "Efficient near-field computation for radiation and scattering from conducting surfaces of arbitrary shape," Progress In Electromagnetics Research, Vol. 69, 267-285, 2007.
doi:10.2528/PIER07010302 Google Scholar