volume | PIER Journals

Abstract

The boundary value solution of electromagnetic radiation from an axis-asymmetric slot antenna on a perfectly conducting prolate spheroid coated with a confocal sheath is presented. The electromagnetic fields are expanded in terms of prolate spheroidal vector wave functions. The unknown expansion coefficients are determined from a set of linear equations derived from the application of boundary conditions on the tangential fields' components. Numerical results for radiation patterns and power are presented. It is found that the thickness of the sheath has a significant effect on the radiated fields, and the radiated power is greatly enhanced for certain values of the sheath thickness.

1. Wait, J. R., "Electromagnetic radiation from spheroidal structures," Advanced Antenna Theory, 523-559, 1969. Google Scholar

2. Schelkunoff, S. A., Advanced Antenna Theory, John Wiley & Sons, 1962.

3. Weeks, W. L., Electromagnetic Theory for Engineering Applications, John Wiley & Sons, 1964.

4. Wait, J. R., "Theories of prolate spheroidal antenna," Radio Sci., Vol. 1. No. 4, No. Vol. 1. 4, 1966. Google Scholar

5. Do-Nhat, T. and R. H. MacPhie, "The input admittance of the thin prolate spheroidal dipole antenna with finite gap width," IEEE Trans. Antennas Propagation, No. 11, 1243-1252, 1995. Google Scholar

6. Li, L. W., M. S. Lenong, T. S. Yeo, and Y. B. Gan, "Electromagnetic radiation from a prolate spheroidal antenna enclosed in a confocal spheroidal radome," IEEE Trans. Antennas Propagation, Vol. 50, No. 11, 1525-1533, 2002.
doi:10.1109/TAP.2002.803950 Google Scholar

7. Zhang, M. and A. A. Sebak, "Radiation characteristics of a slot antenna on a conducting prolate spheroid," Canadian J. Phys., Vol. 73, 376-385, 1995. Google Scholar

8. Flammer, C., Spheroidal Wave Functions, Stanford University Press, 1957.

9. Zhang, M., "Radiation characteristics of asymmetrically slotted spheroidal antennas," Master Thesis, No. 1, 1995. Google Scholar

10. Sinha, B. P. and R. H. MacPhie, "Electromagnetic scattering by prolate spheroids for plane waves with arbitrary polarization and angle of incidence," Radio Sci., Vol. 12. No. 2, No. Vol. 12. 2, 171-184, 1997. Google Scholar

11. Sebak, A. A. and B. P. Sinha, "Scattering by a conducting spheroidal object with dielectric coating at axial incidence," IEEE Trans. Antennas Propagation, Vol. 40, No. 3, 268-274, 1992.
doi:10.1109/8.135468 Google Scholar

12. Mushiake, Y. and R. E. Webster, "Radiation characteristics with power gain for slot on a sphere," IRE Trans. Antennas Propagation, Vol. 5, No. 1, 47-55, 1957.
doi:10.1109/TAP.1957.1144465 Google Scholar

13. Shafai, L. and R. H. Chugh, "Resonance effects in slotted spherical antenna coated with homogeneous materials," Canadian J. Phys., Vol. 51, 2341-2346, 1973. Google Scholar

14. Lin, C. C. and R. E. Mu, "Improved radiation from a spherical antenna by overdense plasma coating," IEEE Trans. Antennas Propagation, Vol. 17, No. 9, 675-678, 1969.
doi:10.1109/TAP.1969.1139506 Google Scholar

15. Richmond, J. H., "Axial slot antenna on dielectric-coated elliptic cylinder," IEEE Trans. Antennas Propagation, Vol. 37, No. 10, 1235-1241, 1989.
doi:10.1109/8.43531 Google Scholar

Dr. Ming Zhang

Dr. Abdel Sebak