volume | PIER Journals

Abstract

In this paper, the modal method is applied to analyze coated circular waveguide terminated by a perfect electric conductor (PEC) plate. The key to this method is the accurate calculation of the propagation constants of modes in coated circular waveguide. To overcome numerical difficulties, such as overflow, encountered in solving characteristic equation, the characteristic equation is modified using Hankel function of the second kind instead of Bessel function of the first kind in the coated layers. The modified characteristic equation can be accurately solved to obtain the propagation constants even for very large circular waveguide with highly lossy coatings. To verify the modified characteristic equation, the attenuation and scattering property of circular waveguide structure have been simulated. Simulation results agree well with the reference results.

1. Lee, C. S. and S. W. Lee, "RCS of a coated circular waveguide terminated by a perfect conductor," IEEE Trans. Antennas Propagat., Vol. 35, No. 4, 391-398, 1987.
doi:10.1109/TAP.1987.1144114

2. Anastassiu, H. T., J. L. Volakis, and D. C. Ross, "The mode matching technique for electromagnetic scattering by cylindrical waveguides with canonical terminations," J. Electromagn. Waves Appl., Vol. 9, No. 11/12, 1363-1391, 1995.

3. Moll, J. W. and R. G. Seecamp, "Calculation of radar reflecting properties of jet engine intakes using a waveguide model," IEEE Aerospace and Electronic Systems, Vol. AES-6, No. 9, 675-683, 1970.

4. Altintas, A., 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 Propagat., Vol. 36, No. 1, 84-96, 1988.
doi:10.1109/8.1077

5. Ling, H., S. W. Lee, and R. C. Chou, "High-frequency RCS of open cavities with rectangular and circular cross sections," IEEE Trans. Antennas Propagat., Vol. 37, No. 5, 648-654, 1989.
doi:10.1109/8.24193

6. Ling, H., R. C. Chou, and S. W. Lee, "Shooting and bouncing rays: calculation RCS of an arbitrarily shaped cavity," IEEE Trans. Antennas Propagat., Vol. 37, No. 2, 194-205, 1989.
doi:10.1109/8.18706

7. Burkholder, R. J., "High-frequency asymptotic methods for analyzing the EM scattering by open-ended waveguide cavities," Thesis (Ph.D.), 1989.

8. Rodríguez, J. L., F. Obelleiro, and A. G. Pino, Iterative solutions of MFIE for computing electromagnetic scattering of large openended cavities, IEE Proc. â€” Microw. Antennas Propag., Vol. 144, No. 2, 141-144, 1997.

9. Wang, T. M. and H. Ling, "Electromagnetic scattering from three-dimensional cavities via a connection scheme," IEEE Trans. Antennas Propagat., Vol. 39, No. 10, 1505-1513, 1991.
doi:10.1109/8.97382

10. Trintinalia, L. C. and H. Ling, "Electromagnetic scattering from 3-D arbitrary coated cavities via a connection scheme using triangular patches," J. Electromagn. Waves Appl., Vol. 8, No. 11, 1411-1423, 1994.

11. Jin, J. M., "Electromagnetic scattering from large, deep, and arbitrarily-shaped open cavities," Electromagn., Vol. 18, 3-34, 1998.

12. Chou, R. C. and S. W. Lee, "Modal attenuation in multilayered coated waveguides," IEEE Trans. Microwave Theory Tech., Vol. 36, No. 7, 1167-1176, 1988.
doi:10.1109/22.3652

13. Harrington, R. F., Time-Harmonic Electromagnetic Fields, McGraw-Hill, New York, 1961.

14. Yeh, C. and G. Lindgren, "Computing the propagation characteristics of radially stratified fibers: an efficient method," Appl. Optics, Vol. 16, No. 2, 483-493, 1977.

15. Collin, R. E., The optimum tapered transmission line matching section, Proc. IRE, Vol. 44, No. 4, 539-548, 1956.

16. Unger, H., "Circular waveguide taper of improved design," Bell System Tech. J., Vol. 37, No. 7, 899-912, 1958.

Dr. Fu-Gang Hu

Dr. Chao-Fu Wang

Dr. Yuan Xu

Dr. Yeow-Beng Gan